I have a 4 cylinder Lister driven generator set for driving all the 3 phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which has a problem starting a couple of my machines in the winter when the oil is very thick. I have been trying to rig up a phase comparison device to determine if the frequency of the set is correct, by connecting the alternator output of one phase to the incoming mains supply via two 240 volt bulbs in series. this has worked on several generators over the years and the lights beat against the mains voltage and when the speed is correct to give 50 Hertz the beating stops and the lights stay on or off. It works very well, however when I tried to connect one phase from the Lister to the mains through my two bulb box, the earth leakage trip tripped. I cannot see why this should be unless there is a neutral to earth leak somewhere. A chase around with a meter did not reveal anything that I did not expect but I am wondering if the neutral wire from the alternator should be strapped to the frame and / or run to an earth pole in the outside ground. The incoming mains is earthed by a copper rod below the electric meter.

A small portable single phase generator which is not earthed anywhere but which has an earth wire out just connected to it's chassis, performs perfectly and as I can also test this against the Lister with no problem I have set the little engine as accurately as I can to the mains frequency and then connect this to the Lister set and re-synchronized it. I want to mount the frequency setting facility permanently so I would rather fix the problem. Would it be better to run an earth wire across the workshop or bang a galvanized earth pole into the ground outside adjacent to the generator. set

What should I do about this tripping, is it an earthing problem or what?
Any comments would be appreciated. By the way I have a very high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen running and is really too good to scrap.

Thanks George.

On Monday, 15 August 2016 16:10:24 UTC+1, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3 phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which has a problem starting a couple of my machines in the winter when the oil is very thick. I have been trying to rig up a phase comparison device to determine if the frequency of the set is correct, by connecting the alternator output of one phase to the incoming mains supply via two 240 volt bulbs in series. this has worked on several generators over the years and the lights beat against the mains voltage and when the speed is correct to give 50 Hertz the beating stops and the lights stay on or off. It works very well, however when I tried to connect one phase from the Lister to the mains through my two bulb box, the earth leakage trip tripped. I cannot see why this should be unless there is a neutral to earth leak somewhere. A chase around with a meter did not reveal anything that I did not expect but I am wondering if the neutral wire from the alternator should be strapped to the frame and / or run to an earth pole in the outside ground. The incoming mains is earthed by a copper rod below the electric meter.

A small portable single phase generator which is not earthed anywhere but which has an earth wire out just connected to it's chassis, performs perfectly and as I can also test this against the Lister with no problem I have set the little engine as accurately as I can to the mains frequency and then connect this to the Lister set and re-synchronized it. I want to mount the frequency setting facility permanently so I would rather fix the problem.. Would it be better to run an earth wire across the workshop or bang a galvanized earth pole into the ground outside adjacent to the generator. set

What should I do about this tripping, is it an earthing problem or what?
Any comments would be appreciated. By the way I have a very high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen running and is really too good to scrap.

Thanks George.


The large genny frame & neutral ought to be earthed, but doing so won't solve the RCD tripping. To avoid a trip you'd need both neutrals connected, and the bulbs live to live, and no earth leakage at the genny or anything connected to it. However I doubt very much this would be legal, since the gen can then backfeed the mains supply in some situations.

FWIW indicator neons consume far less current than filament bulbs.


NT

On Mon, 15 Aug 2016 08:20:14 -0700, tabbypurr wrote:

====snip====


FWIW indicator neons consume far less current than filament bulbs.


Totally unsuited for use as a "Synchroscope", they require about 90v to
strike and will extinguish at about 60 volts. Far better to use a couple
of high efficiency panel lamp LEDs in antiparallel with a 5W 100K ballast
resistor in series.

Since you need to accurately determine the extinguishing point of the
light curve (minimal voltage difference across the sychronising breaker's
contacts), you could add a 10 to 15K half watt resistor in series between
the 5W resistor and the LEDs with a pair of 10v 400mW zenners in
antiseries across the half watt resistor and LED part of the circuit to
limit the maximum brightness and avoid dazzle to better facilitate
detection of the minimum voltage difference point required to determine
the least dramatic moment at which to close the synchronising breaker.

--
Johnny B Good

On 15/08/2016 21:52, Johnny B Good wrote:
On Mon, 15 Aug 2016 08:20:14 -0700, tabbypurr wrote:

====snip====


FWIW indicator neons consume far less current than filament bulbs.


Totally unsuited for use as a "Synchroscope", they require about 90v to
strike and will extinguish at about 60 volts. Far better to use a couple
of high efficiency panel lamp LEDs in antiparallel with a 5W 100K ballast
resistor in series.

I'm going to bite.

In my university days I was told that it was difficult to synchronise
generators on what the article below calls the Three Dark Method. And
that the Two Bright, One Dark Method illustrated in this article gave a
reduced phase error as the eye could compare brightness and colour of
two bulbs. Of course the bulbs had to be matched, but if they were from
the same batch then they probably would be.

http://www.industrial-electronics.com/elecy3_13.html

Since you need to accurately determine the extinguishing point of the
light curve (minimal voltage difference across the sychronising breaker's
contacts), you could add a 10 to 15K half watt resistor in series between
the 5W resistor and the LEDs with a pair of 10v 400mW zenners in
antiseries across the half watt resistor and LED part of the circuit to
limit the maximum brightness and avoid dazzle to better facilitate
detection of the minimum voltage difference point required to determine
the least dramatic moment at which to close the synchronising breaker.

I'm sure there are many ways. The issue here was to reduce any currents
to well below any earth leakage threshold.

On Mon, 15 Aug 2016 22:14:07 +0100, Fredxxx wrote:

On 15/08/2016 21:52, Johnny B Good wrote:
On Mon, 15 Aug 2016 08:20:14 -0700, tabbypurr wrote:

====snip====


FWIW indicator neons consume far less current than filament bulbs.


Totally unsuited for use as a "Synchroscope", they require about 90v
to
strike and will extinguish at about 60 volts. Far better to use a
couple of high efficiency panel lamp LEDs in antiparallel with a 5W
100K ballast resistor in series.

I'm going to bite.

In my university days I was told that it was difficult to synchronise
generators on what the article below calls the Three Dark Method. And
that the Two Bright, One Dark Method illustrated in this article gave a
reduced phase error as the eye could compare brightness and colour of
two bulbs. Of course the bulbs had to be matched, but if they were from
the same batch then they probably would be.

http://www.industrial-electronics.com/elecy3_13.html

Since you need to accurately determine the extinguishing point of the
light curve (minimal voltage difference across the sychronising
breaker's contacts), you could add a 10 to 15K half watt resistor in
series between the 5W resistor and the LEDs with a pair of 10v 400mW
zenners in antiseries across the half watt resistor and LED part of the
circuit to limit the maximum brightness and avoid dazzle to better
facilitate detection of the minimum voltage difference point required
to determine the least dramatic moment at which to close the
synchronising breaker.

I'm sure there are many ways. The issue here was to reduce any currents
to well below any earth leakage threshold.

I was addressing the issue of using neons in place of incandescent lamps
to determine synchronisation between two generators (in this case, every
generator connected to the national grid and your lister driven 3 phase
genset).

As I understand it, you're not trying to parallel up your 3 phase genset
to the public mains supply, just using a single phase incandescent lamp
synchroscope to use the mains frequency as a reference by which to set
the speed of your 3 phase genset the use of which now seems to be causing
the earth leakage breaker to trip.

I suspect that the mistake you've made is to plug into a 13A wall socket
that's protected by an ELCB or equivilent to access the mains supply as
your frequency reference.

If, otoh, the consumer unit is protected by a whole house ELCB, then
your simple incandescent lamps synchroscope just isn't "Going to 'cut
it'" and, contrary to good sense, your cheapest option may prove to be
tabbypurr's suggested use of neon lamps (but only because you're not
going to be relying on it to *actually* parallel up *one* of the three
phases of your genset to the mains supply, merely use it to ascertain
when your genset is frequency, but not phase, matched to the mains
supply).

Incidentally, I'd crossbond the genset frame to your local earth point
and, for good measure, crossbond the genset's neutral to your consumer
unit's incoming neutral. Protection against 'earthing faults' demands
such crossbonding of the neutrals and (frame) 'earths in order to
function properly (fuses and elcbs).

Good luck % HTH

--
Johnny B Good

On Thursday, 18 August 2016 00:05:54 UTC+1, Johnny B Good wrote:
On Mon, 15 Aug 2016 22:14:07 +0100, Fredxxx wrote:
On 15/08/2016 21:52, Johnny B Good wrote:
On Mon, 15 Aug 2016 08:20:14 -0700, tabbypurr wrote:

====snip====


FWIW indicator neons consume far less current than filament bulbs.


Totally unsuited for use as a "Synchroscope", they require about 90v
to
strike and will extinguish at about 60 volts. Far better to use a
couple of high efficiency panel lamp LEDs in antiparallel with a 5W
100K ballast resistor in series.

I'm going to bite.

In my university days I was told that it was difficult to synchronise
generators on what the article below calls the Three Dark Method. And
that the Two Bright, One Dark Method illustrated in this article gave a
reduced phase error as the eye could compare brightness and colour of
two bulbs. Of course the bulbs had to be matched, but if they were from
the same batch then they probably would be.

http://www.industrial-electronics.com/elecy3_13.html

Since you need to accurately determine the extinguishing point of the
light curve (minimal voltage difference across the sychronising
breaker's contacts), you could add a 10 to 15K half watt resistor in
series between the 5W resistor and the LEDs with a pair of 10v 400mW
zenners in antiseries across the half watt resistor and LED part of the
circuit to limit the maximum brightness and avoid dazzle to better
facilitate detection of the minimum voltage difference point required
to determine the least dramatic moment at which to close the
synchronising breaker.

I'm sure there are many ways. The issue here was to reduce any currents
to well below any earth leakage threshold.

I was addressing the issue of using neons in place of incandescent lamps
to determine synchronisation between two generators (in this case, every
generator connected to the national grid and your lister driven 3 phase
genset).

As I understand it, you're not trying to parallel up your 3 phase genset
to the public mains supply, just using a single phase incandescent lamp
synchroscope to use the mains frequency as a reference by which to set
the speed of your 3 phase genset the use of which now seems to be causing
the earth leakage breaker to trip.

I suspect that the mistake you've made is to plug into a 13A wall socket
that's protected by an ELCB or equivilent to access the mains supply as
your frequency reference.

If, otoh, the consumer unit is protected by a whole house ELCB, then
your simple incandescent lamps synchroscope just isn't "Going to 'cut
it'" and, contrary to good sense, your cheapest option may prove to be
tabbypurr's suggested use of neon lamps (but only because you're not
going to be relying on it to *actually* parallel up *one* of the three
phases of your genset to the mains supply, merely use it to ascertain
when your genset is frequency, but not phase, matched to the mains
supply).

Neons won't get you in sync, but they will compare the frequencies without tripping anything. Filaments have much more brightness change around peak voltage, so are good to sync, but also trip RCDs.


NT

On 18/08/2016 00:05, Johnny B Good wrote:
On Mon, 15 Aug 2016 22:14:07 +0100, Fredxxx wrote:

On 15/08/2016 21:52, Johnny B Good wrote:
On Mon, 15 Aug 2016 08:20:14 -0700, tabbypurr wrote:

====snip====


FWIW indicator neons consume far less current than filament bulbs.


Totally unsuited for use as a "Synchroscope", they require about 90v
to
strike and will extinguish at about 60 volts. Far better to use a
couple of high efficiency panel lamp LEDs in antiparallel with a 5W
100K ballast resistor in series.

I'm going to bite.

In my university days I was told that it was difficult to synchronise
generators on what the article below calls the Three Dark Method. And
that the Two Bright, One Dark Method illustrated in this article gave a
reduced phase error as the eye could compare brightness and colour of
two bulbs. Of course the bulbs had to be matched, but if they were from
the same batch then they probably would be.

http://www.industrial-electronics.com/elecy3_13.html

Since you need to accurately determine the extinguishing point of the
light curve (minimal voltage difference across the sychronising
breaker's contacts), you could add a 10 to 15K half watt resistor in
series between the 5W resistor and the LEDs with a pair of 10v 400mW
zenners in antiseries across the half watt resistor and LED part of the
circuit to limit the maximum brightness and avoid dazzle to better
facilitate detection of the minimum voltage difference point required
to determine the least dramatic moment at which to close the
synchronising breaker.

I'm sure there are many ways. The issue here was to reduce any currents
to well below any earth leakage threshold.

I was addressing the issue of using neons in place of incandescent lamps
to determine synchronisation between two generators (in this case, every
generator connected to the national grid and your lister driven 3 phase
genset).

As I understand it, you're not trying to parallel up your 3 phase genset
to the public mains supply, just using a single phase incandescent lamp
synchroscope to use the mains frequency as a reference by which to set
the speed of your 3 phase genset the use of which now seems to be causing
the earth leakage breaker to trip.

I suspect that the mistake you've made is to plug into a 13A wall socket
that's protected by an ELCB or equivilent to access the mains supply as
your frequency reference.

If, otoh, the consumer unit is protected by a whole house ELCB, then
your simple incandescent lamps synchroscope just isn't "Going to 'cut
it'" and, contrary to good sense, your cheapest option may prove to be
tabbypurr's suggested use of neon lamps (but only because you're not
going to be relying on it to *actually* parallel up *one* of the three
phases of your genset to the mains supply, merely use it to ascertain
when your genset is frequency, but not phase, matched to the mains
supply).

Incidentally, I'd crossbond the genset frame to your local earth point
and, for good measure, crossbond the genset's neutral to your consumer
unit's incoming neutral. Protection against 'earthing faults' demands
such crossbonding of the neutrals and (frame) 'earths in order to
function properly (fuses and elcbs).

Good luck % HTH

If the OP has a RCD, then the neutrals should be bonded after they have
passed their respective RCDs, so that any current in the live phase is
matched in the neutral conductor.

I do agree the use of neons with their very low current draw should be
ideal in determining frequency errors.

I'd also be a bit wary about inductive loads and the storage effects one
can get as well.
Most of the things I've seen done were back in the old days when we never
had very sensitive trips like this. Goodness knows what abuse we did to
equiipment and the mains supply!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
wrote in message
...
On Monday, 15 August 2016 16:10:24 UTC+1, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which
has a problem starting a couple of my machines in the winter when the oil
is very thick. I have been trying to rig up a phase comparison device to
determine if the frequency of the set is correct, by connecting the
alternator output of one phase to the incoming mains supply via two 240
volt bulbs in series. this has worked on several generators over the years
and the lights beat against the mains voltage and when the speed is
correct to give 50 Hertz the beating stops and the lights stay on or off.
It works very well, however when I tried to connect one phase from the
Lister to the mains through my two bulb box, the earth leakage trip
tripped. I cannot see why this should be unless there is a neutral to
earth leak somewhere. A chase around with a meter did not reveal anything
that I did not expect but I am wondering if the neutral wire from the
alternator should be strapped to the frame and / or run to an earth pole
in the outside ground. The incoming mains is earthed by a copper rod
below the electric meter.

A small portable single phase generator which is not earthed anywhere but
which has an earth wire out just connected to it's chassis, performs
perfectly and as I can also test this against the Lister with no problem I
have set the little engine as accurately as I can to the mains frequency
and then connect this to the Lister set and re-synchronized it. I want to
mount the frequency setting facility permanently so I would rather fix the
problem. Would it be better to run an earth wire across the workshop or
bang a galvanized earth pole into the ground outside adjacent to the
generator. set

What should I do about this tripping, is it an earthing problem or what?
Any comments would be appreciated. By the way I have a very high quality
30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen
running and is really too good to scrap.

Thanks George.


The large genny frame & neutral ought to be earthed, but doing so won't
solve the RCD tripping. To avoid a trip you'd need both neutrals connected,
and the bulbs live to live, and no earth leakage at the genny or anything
connected to it. However I doubt very much this would be legal, since the
gen can then backfeed the mains supply in some situations.

FWIW indicator neons consume far less current than filament bulbs.


NT

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but
which has a problem starting a couple of my machines in the winter
when the oil is very thick. I have been trying to rig up a phase
comparison device to determine if the frequency of the set is
correct, by connecting the alternator output of one phase to the
incoming mains supply via two 240 volt bulbs in series. this has
worked on several generators over the years and the lights beat
against the mains voltage and when the speed is correct to give 50
Hertz the beating stops and the lights stay on or off. It works very
well, however when I tried to connect one phase from the Lister to
the mains through my two bulb box, the earth leakage trip tripped.

Do you really mean Earth Leakage Breaker, or a new fangled RCD? And is
this mains side or generator side?

Are the neutrals from your generator and mains commoned? Any unbalanced
phase current will mean that the neutral from your generator will
wander, and if there is any connection to earth, then an earth current
will pass.

If commoned, then the sum of 3 phases + neutral should always be zero.
Perhaps look out for an unintended connection between neutral and earth.

On Mon, 15 Aug 2016 19:32:19 +0100, Fredxxx wrote:

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which
has a problem starting a couple of my machines in the winter when the
oil is very thick. I have been trying to rig up a phase comparison
device to determine if the frequency of the set is correct, by
connecting the alternator output of one phase to the incoming mains
supply via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains voltage
and when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off. It works very well, however when I tried to
connect one phase from the Lister to the mains through my two bulb box,
the earth leakage trip tripped.

Do you really mean Earth Leakage Breaker, or a new fangled RCD? And is
this mains side or generator side?

Are the neutrals from your generator and mains commoned? Any unbalanced
phase current will mean that the neutral from your generator will
wander, and if there is any connection to earth, then an earth current
will pass.

If commoned, then the sum of 3 phases + neutral should always be zero.
Perhaps look out for an unintended connection between neutral and earth.

As I understand the OP, George isn't trying to synch up to the mains,
just use the mains frequency as a reference by which to set the speed of
his 3 phase genset. I suspect his incandescent lamps 'synchroscope' is
being fed via an elcb protected supply (13A socket in his workshop).
Normally, the uneconomic consumption of such a lamps based synchroscope
is not an issue but, in this particular (peculiar?) case, it's now
creating an elcb issue.

If he doesn't care for tabbypurr's idea of using neon lamps, he could
use a one to one isolating transformer between his synchroscope box and
the 13A mains socket so that the 'neutral' connection of the secondary
winding is to the genset's neutral instead of the consumer unit's
neutral. The potential 180 degree phase reversal won't be an issue when
the synchroscope is being used simply to match frequency (however, the
transformer secondary could be wired for phase coherence if phase
matching is required - in this instance it isn't).

As a matter of fact, there are plenty of alternative ways by which to
compare two different source frequencies, it's just a pity that George's
tried and trusted incandescent lamps based synchroscope method is
incompatable with ELBS. :-)

--
Johnny B Good

On Thursday, 18 August 2016 00:24:08 UTC+1, Johnny B Good wrote:
On Mon, 15 Aug 2016 19:32:19 +0100, Fredxxx wrote:

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which
has a problem starting a couple of my machines in the winter when the
oil is very thick. I have been trying to rig up a phase comparison
device to determine if the frequency of the set is correct, by
connecting the alternator output of one phase to the incoming mains
supply via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains voltage
and when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off. It works very well, however when I tried to
connect one phase from the Lister to the mains through my two bulb box,
the earth leakage trip tripped.

Do you really mean Earth Leakage Breaker, or a new fangled RCD? And is
this mains side or generator side?

Are the neutrals from your generator and mains commoned? Any unbalanced
phase current will mean that the neutral from your generator will
wander, and if there is any connection to earth, then an earth current
will pass.

If commoned, then the sum of 3 phases + neutral should always be zero.
Perhaps look out for an unintended connection between neutral and earth.

As I understand the OP, George isn't trying to synch up to the mains,
just use the mains frequency as a reference by which to set the speed of
his 3 phase genset. I suspect his incandescent lamps 'synchroscope' is
being fed via an elcb protected supply (13A socket in his workshop).
Normally, the uneconomic consumption of such a lamps based synchroscope
is not an issue but, in this particular (peculiar?) case, it's now
creating an elcb issue.

If he doesn't care for tabbypurr's idea of using neon lamps, he could
use a one to one isolating transformer between his synchroscope box and
the 13A mains socket so that the 'neutral' connection of the secondary
winding is to the genset's neutral instead of the consumer unit's
neutral. The potential 180 degree phase reversal won't be an issue when
the synchroscope is being used simply to match frequency (however, the
transformer secondary could be wired for phase coherence if phase
matching is required - in this instance it isn't).

As a matter of fact, there are plenty of alternative ways by which to
compare two different source frequencies, it's just a pity that George's
tried and trusted incandescent lamps based synchroscope method is
incompatable with ELBS. :-)

The usual voltage ELCBs usually don't care about a lightbulb's worth of earth leakge. RCDs do, sometimes aka current ELCBs. Nothing cares about neons.


NT

On Wed, 17 Aug 2016 16:51:25 -0700, tabbypurr wrote:

On Thursday, 18 August 2016 00:24:08 UTC+1, Johnny B Good wrote:

====snip====


As a matter of fact, there are plenty of alternative ways by which to
compare two different source frequencies, it's just a pity that
George's tried and trusted incandescent lamps based synchroscope method
is incompatable with ELBS. :-)

The usual voltage ELCBs usually don't care about a lightbulb's worth of
earth leakge. RCDs do, sometimes aka current ELCBs. Nothing cares about
neons.


In a sense, neons are like 'stupidity', not a problem in small
quantities but a major force to be reckoned with in very large numbers as
most politicians are only too well aware. :-)

BTW, thanks for the heads up on ELCBs and RCDs. I can never remember the
differences between what would seem, on the face of it, to be devices
with essentially the same function. We don't have a single one of either
of those devices in this house, hence my lack of motivation to learn the
distinction between them. :-)

--
Johnny B Good

On 18/08/2016 01:42, Johnny B Good wrote:
On Wed, 17 Aug 2016 16:51:25 -0700, tabbypurr wrote:

On Thursday, 18 August 2016 00:24:08 UTC+1, Johnny B Good wrote:

====snip====


As a matter of fact, there are plenty of alternative ways by which to
compare two different source frequencies, it's just a pity that
George's tried and trusted incandescent lamps based synchroscope method
is incompatable with ELBS. :-)

The usual voltage ELCBs usually don't care about a lightbulb's worth of
earth leakge. RCDs do, sometimes aka current ELCBs. Nothing cares about
neons.


In a sense, neons are like 'stupidity', not a problem in small
quantities but a major force to be reckoned with in very large numbers as
most politicians are only too well aware. :-)

BTW, thanks for the heads up on ELCBs and RCDs. I can never remember the
differences between what would seem, on the face of it, to be devices
with essentially the same function. We don't have a single one of either
of those devices in this house, hence my lack of motivation to learn the
distinction between them. :-)

A reasonable description here for those who are interested:

http://wiki.diyfaq.org.uk/index.php/RCD
http://wiki.diyfaq.org.uk/index.php/ELCB

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine if
the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt bulbs
in series. this has worked on several generators over the years and the
lights beat against the mains voltage and when the speed is correct to
give 50 Hertz the beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough. Florries
would, though.

--
*And the cardiologist' s diet: - If it tastes good spit it out.

Dave Plowman London SW
To e-mail, change noise into sound.

On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine if
the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt bulbs
in series. this has worked on several generators over the years and the
lights beat against the mains voltage and when the speed is correct to
give 50 Hertz the beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough. Florries
would, though.

Household filament lamps can be used for a useful chunk of the audio spectrum, so have no difficulty following a few Hz.


NT

On Tuesday, 16 August 2016 09:25:50 UTC+1, wrote:
On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine if
the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt bulbs
in series. this has worked on several generators over the years and the
lights beat against the mains voltage and when the speed is correct to
give 50 Hertz the beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough. Florries
would, though.

Household filament lamps can be used for a useful chunk of the audio spectrum, so have no difficulty following a few Hz.


NT


Thanks for all the useful suggestions and advice, it will take a while to go through then ,ut to clarify, I do not need very accurate frequency comparisons as the Lister engine will vary a bit according to the load anyway. I shall have a look this morning and identify exactly what is is that is tripping and what it says on it.

The motor I mentioned came from a motor alternator set which was used to produce 3 phase 415 supply for some industrial computer equipment that required a frequency of 400 cycles/sec as it was then (Hertz now) The motor and alternator were mounted in line on a very heavy chassis and coupled together by a big rubber cush drive. I still have all the kit but it is all separated and who would want a 400 Hz supply anyway. I also have a 65 Kw alternator on a big frame, the same Computer quality, - this has been superseded by the Lister Genny. I can send pictures if I had emails to anyone or maybe I shall post it on my website if I can find time : maribelecosystems,co,uk It was all made with cost not being an issue, I live in Norfolk, NE of Norwich, but the motor is fairly easy to transport.

Regards George.

On 16/08/2016 10:19, George wrote:
On Tuesday, 16 August 2016 09:25:50 UTC+1, wrote:
On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News)
wrote:
In article
, George
wrote:
I have been trying to rig up a phase comparison device to
determine if the frequency of the set is correct, by connecting
the alternator output of one phase to the incoming mains supply
via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains
voltage and when the speed is correct to give 50 Hertz the
beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the
audio spectrum, so have no difficulty following a few Hz.


NT


Thanks for all the useful suggestions and advice, it will take a
while to go through then ,ut to clarify, I do not need very accurate
frequency comparisons as the Lister engine will vary a bit according
to the load anyway. I shall have a look this morning and identify
exactly what is is that is tripping and what it says on it.

The motor I mentioned came from a motor alternator set which was used
to produce 3 phase 415 supply for some industrial computer equipment
that required a frequency of 400 cycles/sec as it was then (Hertz
now)

Most aircraft based power systems are 400Hz - perhaps this was computer
kit originally intended to fly.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tuesday, 16 August 2016 10:37:54 UTC+1, John Rumm wrote:
On 16/08/2016 10:19, George wrote:
On Tuesday, 16 August 2016 09:25:50 UTC+1, wrote:
On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News)
wrote:
In article
, George
wrote:
I have been trying to rig up a phase comparison device to
determine if the frequency of the set is correct, by connecting
the alternator output of one phase to the incoming mains supply
via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains
voltage and when the speed is correct to give 50 Hertz the
beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the
audio spectrum, so have no difficulty following a few Hz.


NT


Thanks for all the useful suggestions and advice, it will take a
while to go through then ,ut to clarify, I do not need very accurate
frequency comparisons as the Lister engine will vary a bit according
to the load anyway. I shall have a look this morning and identify
exactly what is is that is tripping and what it says on it.

The motor I mentioned came from a motor alternator set which was used
to produce 3 phase 415 supply for some industrial computer equipment
that required a frequency of 400 cycles/sec as it was then (Hertz
now)

Most aircraft based power systems are 400Hz - perhaps this was computer
kit originally intended to fly.

Any particular reason for that frequency or is it just that it had to be something and with allied kit needing to co-opt/nationalcompanies merging etc.?

On Tue, 16 Aug 2016 02:19:23 -0700 (PDT), George
wrote:

I do not need very accurate frequency comparisons as the Lister engine will vary a bit according to the load anyway. I shall have a look this morning and identify exactly what is is that is tripping and what it says on it.

You could just get a frequency meter: either a digital one, like:

"AC 80-300V/30-70HZ 3in1 LCD Time Voltage Frequency Combo Meter For Generator
http://r.ebay.com/q5jugZ"
This does frequency, voltage, and runtime, for 10 quid.

Or get something a bit more fitting to a Lister, i.e. an analog "vibrating reed
frequency meter", aka "resonant reed frequency meter". Or a mains fluorescent
light, used as a strobe to illuminate an on an index mark on the generator?



Thomas Prufer

On Tue, 16 Aug 2016 14:11:19 +0200, Thomas Prufer wrote:

On Tue, 16 Aug 2016 02:19:23 -0700 (PDT), George
wrote:

I do not need very accurate frequency comparisons as the Lister engine
will vary a bit according to the load anyway. I shall have a look this
morning and identify exactly what is is that is tripping and what it
says on it.

You could just get a frequency meter: either a digital one, like:

"AC 80-300V/30-70HZ 3in1 LCD Time Voltage Frequency Combo Meter For
Generator http://r.ebay.com/q5jugZ"
This does frequency, voltage, and runtime, for 10 quid.

Or get something a bit more fitting to a Lister, i.e. an analog
"vibrating reed frequency meter", aka "resonant reed frequency meter".
Or a mains fluorescent light, used as a strobe to illuminate an on an
index mark on the generator?

See what I meant by "various ways" to set the speed of that Lister
powered genset? :-)

--
Johnny B Good

On 16/08/2016 10:19, George wrote:
who would want a 400 Hz supply anyway.

An aviation museum perhaps? Widely used in aircraft.

Andy

On Tuesday, 16 August 2016 21:41:38 UTC+1, Vir Campestris wrote:
On 16/08/2016 10:19, George wrote:
who would want a 400 Hz supply anyway.

An aviation museum perhaps? Widely used in aircraft.

I was thinking that. I am going to Cosford soon to see if I can get a better understanding of the compressor problem in Jets. I have no idea if they would be interested in anything like that. Come to think of it the one unfinished product locally; a Spitfire in the Stoke Pottery museum, qualifies it as an aircraft museum.

What can the OP tell us about the kit?

In article ,
wrote:
On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine
if the frequency of the set is correct, by connecting the
alternator output of one phase to the incoming mains supply via two
240 volt bulbs in series. this has worked on several generators
over the years and the lights beat against the mains voltage and
when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the audio
spectrum, so have no difficulty following a few Hz.

Could you run that by me again? ;-)

TV cameras in the 25 frame days were very sensitive to lighting running at
a different speed. Because they used their own frequency standard which
was far more stable than mains. Florries and some discharge types would
cause flicker or hum bars on the picture. Tungsten not - I assume because
of the persistence of the filament. Even with domestic GLS lamps.

If you wanted to use high efficiency florries, you'd normally used three
phase with alternate phase tubes close together. Or the less efficient
tubes with long persistent phosphors.

--
*I used to have an open mind but my brains kept falling out *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
TV cameras in the 25 frame days were very sensitive to lighting running at
a different speed. Because they used their own frequency standard which
was far more stable than mains. Florries and some discharge types would
cause flicker or hum bars on the picture. Tungsten not - I assume because
of the persistence of the filament. Even with domestic GLS lamps.

If you wanted to use high efficiency florries, you'd normally used three
phase with alternate phase tubes close together. Or the less efficient
tubes with long persistent phosphors.

I think when broadcasters first changed over from locking the TV frequency
to the mains frequency, when for the first time the mains lights could drift
in frequency through the day but the TV frequency was accurately controlled,
they used to use DC-powered lights or else power the tungsten lights from
different phases.

When shooting high-speed film (for slow-motion sequences) it's still common
to use DC lights. There's a boxing scene in the film The Krays where they
didn't do this and in the slow-motion sequences you can see some variation
in exposure (ie flicker) between different frames. However that affects the
whole frame (being film) which is less noticeable than affecting parts of
the frame, giving rise to rolling hum bars, as with TV cameras.

An additional problem with fluorescents is that the various phosphors have
different decay times, so on fast-moving objects you see an orange "tail"
where the redder phosphor in the fluorescent tube has a slightly longer
decay time than the bluer phosphor.

When I was in America around the time of my nephew's birth, I shot some
video with my sister's UK-standard camcorder. Tungsten lights, at 60 Hz,
were fine, but the fluorescents in the "Birth Center" (maternity hospital)
caused nasty strobing that varied in colour as well as brightness.

In article ,
NY wrote:
I think when broadcasters first changed over from locking the TV
frequency to the mains frequency, when for the first time the mains
lights could drift in frequency through the day but the TV frequency
was accurately controlled, they used to use DC-powered lights or else
power the tungsten lights from different phases.

Don't think so. I started in TV in the early '60s. Pretty well all lights
were AC. And the majority - fed from the grid - on one phase for safety
reasons.

When shooting high-speed film (for slow-motion sequences) it's still
common to use DC lights. There's a boxing scene in the film The Krays
where they didn't do this and in the slow-motion sequences you can see
some variation in exposure (ie flicker) between different frames.
However that affects the whole frame (being film) which is less
noticeable than affecting parts of the frame, giving rise to rolling
hum bars, as with TV cameras.

The standard grid lighting used for boxing matches being televised was
three phase fluorescent. Ordinary TV lighting could give glare - so not
allowed by the boxing authorities. All explained to me in some detail when
we had a genuine pro boxing match in the studio.

An additional problem with fluorescents is that the various phosphors
have different decay times, so on fast-moving objects you see an orange
"tail" where the redder phosphor in the fluorescent tube has a slightly
longer decay time than the bluer phosphor.

You'd probably choose the tubes carefully for TV use - where you can. At
one time they weren't used at all where there was a choice - but high
frequency types changed that as they were more efficient for some types of
location work, perhaps run from batteries. Before LEDs

When I was in America around the time of my nephew's birth, I shot some
video with my sister's UK-standard camcorder. Tungsten lights, at 60 Hz,
were fine, but the fluorescents in the "Birth Center" (maternity
hospital) caused nasty strobing that varied in colour as well as
brightness.

Yes. As I said, tungsten doesn't normally give any problems. Hence my
query about it being used as said. Same with a lathe, etc. Florries can
make it look stationary. But tungsten not.

--
*Save the whale - I'll have it for my supper*

Dave Plowman London SW
To e-mail, change noise into sound.

On Tuesday, 16 August 2016 13:06:09 UTC+1, Dave Plowman (News) wrote:
In article ,
tabbypurr wrote:
On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine
if the frequency of the set is correct, by connecting the
alternator output of one phase to the incoming mains supply via two
240 volt bulbs in series. this has worked on several generators
over the years and the lights beat against the mains voltage and
when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the audio
spectrum, so have no difficulty following a few Hz.

Could you run that by me again? ;-)

TV cameras in the 25 frame days were very sensitive to lighting running at
a different speed. Because they used their own frequency standard which
was far more stable than mains. Florries and some discharge types would
cause flicker or hum bars on the picture. Tungsten not - I assume because
of the persistence of the filament. Even with domestic GLS lamps.

If you wanted to use high efficiency florries, you'd normally used three
phase with alternate phase tubes close together. Or the less efficient
tubes with long persistent phosphors.

To indicate speed difference, tungsten only need do a few Hz, which it does easily.

Household 60w lamps can put out light at audio frequencies, albeit heavily attentuated, and were occasionally used for that by hobbyists. Such lamps are different to 650w/1kW theatre lamps, the latter having far thicker filaments and thus much longer time constants.


NT

In article ,
wrote:
Household 60w lamps can put out light at audio frequencies, albeit
heavily attentuated, and were occasionally used for that by hobbyists.

You've still lost me. Do you mean the sound to light sort of thing?

--
*Sticks and stones may break my bones but whips and chains excite me*

Dave Plowman London SW
To e-mail, change noise into sound.

On Tue, 16 Aug 2016 01:25:47 -0700, tabbypurr wrote:

On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine
if the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt
bulbs in series. this has worked on several generators over the
years and the lights beat against the mains voltage and when the
speed is correct to give 50 Hertz the beating stops and the lights
stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the audio
spectrum, so have no difficulty following a few Hz.

Not very well, and not to a very good depth of modulation (3 or 4
percent at 2KHz or so with a DC biassed torch bulb istr).

--
Johnny B Good

On Thursday, 18 August 2016 00:37:27 UTC+1, Johnny B Good wrote:
On Tue, 16 Aug 2016 01:25:47 -0700, tabbypurr wrote:

On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News) wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine
if the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt
bulbs in series. this has worked on several generators over the
years and the lights beat against the mains voltage and when the
speed is correct to give 50 Hertz the beating stops and the lights
stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the audio
spectrum, so have no difficulty following a few Hz.

Not very well, and not to a very good depth of modulation (3 or 4
percent at 2KHz or so with a DC biassed torch bulb istr).

Response depends on rated filament current. Pick high voltage low current for best response.


NT

On Wed, 17 Aug 2016 16:54:38 -0700, tabbypurr wrote:

On Thursday, 18 August 2016 00:37:27 UTC+1, Johnny B Good wrote:
On Tue, 16 Aug 2016 01:25:47 -0700, tabbypurr wrote:

On Tuesday, 16 August 2016 00:53:00 UTC+1, Dave Plowman (News)
wrote:
In article ,
George wrote:
I have been trying to rig up a phase comparison device to
determine if the frequency of the set is correct, by connecting
the alternator output of one phase to the incoming mains supply
via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains
voltage and when the speed is correct to give 50 Hertz the
beating stops and the lights stay on or off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Household filament lamps can be used for a useful chunk of the audio
spectrum, so have no difficulty following a few Hz.

Not very well, and not to a very good depth of modulation (3 or 4
percent at 2KHz or so with a DC biassed torch bulb istr).

Response depends on rated filament current. Pick high voltage low
current for best response.

The cannibalised battery powered transistor radio and 3v torch was the
favoured combination for the transmitter (along with an ORP12(?)
'photocell' and another transistor amplifier (or even the same
cannibalised transistor radio in a switched simplex setup) for the
receiver) amongst the usual age range of 'electronics experimenters',
usually juvenile 'Nerds'. Battery operation kept such experiments 'safe'
in the hands of such child prodigies.

Also, the small compact filament is what gave the 3 volt torch its
relatively 'tight beam' with a modestly sized reflector. The choice was
between a long bulb life and really muffled audio or between short life
with less muffled audio by over-volting the torch bulb by adding a third
cell in series with the two cell battery pack (essentially a pair of C
cells in a cardboard tube) sometimes a couple of partially exhausted 3
volt batteries would be used (then, as now, battery power wasn't cheap).

--
Johnny B Good

On Tue, 16 Aug 2016 00:45:47 +0100, Dave Plowman (News) wrote:

In article ,
George wrote:
I have been trying to rig up a phase comparison device to determine if
the frequency of the set is correct, by connecting the alternator
output of one phase to the incoming mains supply via two 240 volt
bulbs in series. this has worked on several generators over the years
and the lights beat against the mains voltage and when the speed is
correct to give 50 Hertz the beating stops and the lights stay on or
off.

I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Then you've totally misunderstood the principle by which such
incandescent lamps synchroscopes work. In effect, you're using the lamps
as voltage amplitude detectors where brightness depends on the square law
of ac voltage (power function of the product of voltage and current in a
purely resistive load).

It's not the 100 brightness peaks a second we're looking at, it's the
voltage difference between phases from two different supplies that have
their neutrals bonded together. This voltage difference is amplitude
modulated by the frequency *difference* between the two supply sources
and it is *this* 'beat effect' on the lamps' brightness that's being
observed.

--
Johnny B Good

In article ,
Johnny B Good wrote:
I'm amazed a normal tungsten filament bulb reacts quickly enough.
Florries would, though.

Then you've totally misunderstood the principle by which such
incandescent lamps synchroscopes work. In effect, you're using the lamps
as voltage amplitude detectors where brightness depends on the square
law of ac voltage (power function of the product of voltage and current
in a purely resistive load).

It's not the 100 brightness peaks a second we're looking at, it's the
voltage difference between phases from two different supplies that have
their neutrals bonded together. This voltage difference is amplitude
modulated by the frequency *difference* between the two supply sources
and it is *this* 'beat effect' on the lamps' brightness that's being
observed.

Ah. An explanation I understand at last. Thanks. I was thinking more of a
strobe function.

--
*It ain't the size, it's... er... no, it IS ..the size.

Dave Plowman London SW
To e-mail, change noise into sound.

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but
which has a problem starting a couple of my machines in the winter
when the oil is very thick. I have been trying to rig up a phase
comparison device to determine if the frequency of the set is
correct, by connecting the alternator output of one phase to the
incoming mains supply via two 240 volt bulbs in series. this has
worked on several generators over the years and the lights beat
against the mains voltage and when the speed is correct to give 50
Hertz the beating stops and the lights stay on or off. It works very
well, however when I tried to connect one phase from the Lister to
the mains through my two bulb box, the earth leakage trip tripped. I
cannot see why this should be unless there is a neutral to earth leak
somewhere. A chase around with a meter did not reveal anything that
I did not expect but I am wondering if the neutral wire from the
alternator should be strapped to the frame and / or run to an earth
pole in the outside ground. The incoming mains is earthed by a
copper rod below the electric meter.

For clarification do you mean the RCD on the mains supply tripped?

If so, that does not seem very surprising if I have understood the setup
correctly.

If the genny output was truly floating, then I would expect it would
just ride the mains waveform, but sink little or no current (hence the
lamps would not light). However if the lamps are lighting, then you must
be passing current in the mains live wire that is not also present in
the mains neutral - hence the RCD trip. (it would also suggest that one
side of the genny output (i.e. the neutral) is likely bonded to earth.

A small portable single phase generator which is not earthed anywhere
but which has an earth wire out just connected to it's chassis,
performs perfectly and as I can also test this against the Lister
with no problem I have set the little engine as accurately as I can
to the mains frequency and then connect this to the Lister set and
re-synchronized it. I want to mount the frequency setting facility
permanently so I would rather fix the problem. Would it be better to
run an earth wire across the workshop or bang a galvanized earth pole
into the ground outside adjacent to the generator. set

What should I do about this tripping, is it an earthing problem or
what? Any comments would be appreciated. By the way I have a very
high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It
can be seen running and is really too good to scrap.

Thanks George.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tuesday, 16 August 2016 04:02:58 UTC+1, John Rumm wrote:
On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but
which has a problem starting a couple of my machines in the winter
when the oil is very thick. I have been trying to rig up a phase
comparison device to determine if the frequency of the set is
correct, by connecting the alternator output of one phase to the
incoming mains supply via two 240 volt bulbs in series. this has
worked on several generators over the years and the lights beat
against the mains voltage and when the speed is correct to give 50
Hertz the beating stops and the lights stay on or off. It works very
well, however when I tried to connect one phase from the Lister to
the mains through my two bulb box, the earth leakage trip tripped. I
cannot see why this should be unless there is a neutral to earth leak
somewhere. A chase around with a meter did not reveal anything that
I did not expect but I am wondering if the neutral wire from the
alternator should be strapped to the frame and / or run to an earth
pole in the outside ground. The incoming mains is earthed by a
copper rod below the electric meter.

For clarification do you mean the RCD on the mains supply tripped?

If so, that does not seem very surprising if I have understood the setup
correctly.

If the genny output was truly floating, then I would expect it would
just ride the mains waveform, but sink little or no current (hence the
lamps would not light). However if the lamps are lighting, then you must
be passing current in the mains live wire that is not also present in
the mains neutral - hence the RCD trip. (it would also suggest that one
side of the genny output (i.e. the neutral) is likely bonded to earth.

If the windings got hot at any time or received mechanical damage of some sort,that would also trip things up wouldn't it?

I gather that can be cured to a certain extent by warming insulating resin and getting it to suffuse through the windings. I'm not sure how half baked that process or idea is.

On 16/08/2016 10:56, Weatherlawyer wrote:
On Tuesday, 16 August 2016 04:02:58 UTC+1, John Rumm wrote:
On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all
the 3 phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP
but which has a problem starting a couple of my machines in the
winter when the oil is very thick. I have been trying to rig up a
phase comparison device to determine if the frequency of the set
is correct, by connecting the alternator output of one phase to
the incoming mains supply via two 240 volt bulbs in series. this
has worked on several generators over the years and the lights
beat against the mains voltage and when the speed is correct to
give 50 Hertz the beating stops and the lights stay on or off.
It works very well, however when I tried to connect one phase
from the Lister to the mains through my two bulb box, the earth
leakage trip tripped. I cannot see why this should be unless
there is a neutral to earth leak somewhere. A chase around with
a meter did not reveal anything that I did not expect but I am
wondering if the neutral wire from the alternator should be
strapped to the frame and / or run to an earth pole in the
outside ground. The incoming mains is earthed by a copper rod
below the electric meter.

For clarification do you mean the RCD on the mains supply tripped?

If so, that does not seem very surprising if I have understood the
setup correctly.

If the genny output was truly floating, then I would expect it
would just ride the mains waveform, but sink little or no current
(hence the lamps would not light). However if the lamps are
lighting, then you must be passing current in the mains live wire
that is not also present in the mains neutral - hence the RCD trip.
(it would also suggest that one side of the genny output (i.e. the
neutral) is likely bonded to earth.

If the windings got hot at any time or received mechanical damage of
some sort,that would also trip things up wouldn't it?

It could cause the output from that winding to fall, or yo fail
altogether. As to tripping - much depends on the type of circuit breaker
and what its actually protecting.

I gather that can be cured to a certain extent by warming insulating
resin and getting it to suffuse through the windings. I'm not sure
how half baked that process or idea is.

Better quality armature windings will be made like that in the first
place - it keeps dust and abrasive dust out of the windings, and reduces
and vibration in them.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Tue, 16 Aug 2016 04:02:50 +0100, John Rumm wrote:

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which
has a problem starting a couple of my machines in the winter when the
oil is very thick. I have been trying to rig up a phase comparison
device to determine if the frequency of the set is correct, by
connecting the alternator output of one phase to the incoming mains
supply via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains voltage
and when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off. It works very well, however when I tried to
connect one phase from the Lister to the mains through my two bulb box,
the earth leakage trip tripped. I cannot see why this should be unless
there is a neutral to earth leak somewhere. A chase around with a
meter did not reveal anything that I did not expect but I am wondering
if the neutral wire from the alternator should be strapped to the frame
and / or run to an earth pole in the outside ground. The incoming
mains is earthed by a copper rod below the electric meter.

For clarification do you mean the RCD on the mains supply tripped?

If so, that does not seem very surprising if I have understood the setup
correctly.

Nor did it seem surprising to me after re-reading the OP after
responding to tabbypurr's suggestion of using neon lamps in a synchroscope
(not a good idea if you plan to rely on it to determine the point at
which to get the "*least* bang for your buck" when you close the
breaker. :-).

However, purely from a frequency comparison point, a perfectly
acceptable alternative in this situation (provided you don't forget why
neon lamps aren't suited to the task of synchronising phases to within a
few degrees of each other and misuse it for this function).


If the genny output was truly floating, then I would expect it would
just ride the mains waveform, but sink little or no current (hence the
lamps would not light). However if the lamps are lighting, then you must
be passing current in the mains live wire that is not also present in
the mains neutral - hence the RCD trip. (it would also suggest that one
side of the genny output (i.e. the neutral) is likely bonded to earth.

Not just likely, it had *damn well better be* cross-bonded to the
incoming supply's neutral (and earth) or else it won't be safe against
framing faults!

--
Johnny B Good

On 18/08/2016 00:57, Johnny B Good wrote:
On Tue, 16 Aug 2016 04:02:50 +0100, John Rumm wrote:

On 15/08/2016 16:10, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3
phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which
has a problem starting a couple of my machines in the winter when the
oil is very thick. I have been trying to rig up a phase comparison
device to determine if the frequency of the set is correct, by
connecting the alternator output of one phase to the incoming mains
supply via two 240 volt bulbs in series. this has worked on several
generators over the years and the lights beat against the mains voltage
and when the speed is correct to give 50 Hertz the beating stops and
the lights stay on or off. It works very well, however when I tried to
connect one phase from the Lister to the mains through my two bulb box,
the earth leakage trip tripped. I cannot see why this should be unless
there is a neutral to earth leak somewhere. A chase around with a
meter did not reveal anything that I did not expect but I am wondering
if the neutral wire from the alternator should be strapped to the frame
and / or run to an earth pole in the outside ground. The incoming
mains is earthed by a copper rod below the electric meter.

For clarification do you mean the RCD on the mains supply tripped?

If so, that does not seem very surprising if I have understood the setup
correctly.

Nor did it seem surprising to me after re-reading the OP after
responding to tabbypurr's suggestion of using neon lamps in a synchroscope
(not a good idea if you plan to rely on it to determine the point at
which to get the "*least* bang for your buck" when you close the
breaker. :-).

Indeed - making you genny spin at something about equal to mains
frequency is one thing, making it "grid tied" is something quite different!

However, purely from a frequency comparison point, a perfectly
acceptable alternative in this situation (provided you don't forget why
neon lamps aren't suited to the task of synchronising phases to within a
few degrees of each other and misuse it for this function).


If the genny output was truly floating, then I would expect it would
just ride the mains waveform, but sink little or no current (hence the
lamps would not light). However if the lamps are lighting, then you must
be passing current in the mains live wire that is not also present in
the mains neutral - hence the RCD trip. (it would also suggest that one
side of the genny output (i.e. the neutral) is likely bonded to earth.

Not just likely, it had *damn well better be* cross-bonded to the
incoming supply's neutral (and earth) or else it won't be safe against
framing faults!

Well it does rather depend on the application. For small portable
gensets just running individual power tools etc, then an IT[1]
configuration (i.e. both sides of the output windings isolated from
earth) will remain safe even if there is a live to chassis fault since
any indirect contact by an operator to the tools live would simply drag
the "live" side of the generator output to earth potential.

For large three phase gensets running fixed tooling etc, that is a less
desirable setup. Its also no good if you want to power stuff that
expects to have a earth referenced neutral, like a boiler for example
where the flame detection will typically fail without.



[1] Not Information Technology in this case, but a less commonly used
(non) earthing system:

http://wiki.diyfaq.org.uk/index.php/...Earthing_Types


--
Cheers,

John.

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\================================================= ================/

On Monday, 15 August 2016 16:10:24 UTC+1, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3 phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which has a problem starting a couple of my machines in the winter when the oil is very thick. I have been trying to rig up a phase comparison device to determine if the frequency of the set is correct, by connecting the alternator output of one phase to the incoming mains supply via two 240 volt bulbs in series. this has worked on several generators over the years and the lights beat against the mains voltage and when the speed is correct to give 50 Hertz the beating stops and the lights stay on or off. It works very well, however when I tried to connect one phase from the Lister to the mains through my two bulb box, the earth leakage trip tripped. I cannot see why this should be unless there is a neutral to earth leak somewhere. A chase around with a meter did not reveal anything that I did not expect but I am wondering if the neutral wire from the alternator should be strapped to the frame and / or run to an earth pole in the outside ground. The incoming mains is earthed by a copper rod below the electric meter.

A small portable single phase generator which is not earthed anywhere but which has an earth wire out just connected to it's chassis, performs perfectly and as I can also test this against the Lister with no problem I have set the little engine as accurately as I can to the mains frequency and then connect this to the Lister set and re-synchronized it. I want to mount the frequency setting facility permanently so I would rather fix the problem.. Would it be better to run an earth wire across the workshop or bang a galvanized earth pole into the ground outside adjacent to the generator. set

What should I do about this tripping, is it an earthing problem or what?
Any comments would be appreciated. By the way I have a very high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen running and is really too good to scrap.

Thanks George.

How far from Stoke on Trent are you and can you tell me more about the motor please?

On Monday, 15 August 2016 16:10:24 UTC+1, George wrote:
I have a 4 cylinder Lister driven generator set for driving all the 3 phase devices in my workshop.

There is also a 2 to 3 phase converter that powers up to 3 HP but which has a problem starting a couple of my machines in the winter when the oil is very thick. I have been trying to rig up a phase comparison device to determine if the frequency of the set is correct, by connecting the alternator output of one phase to the incoming mains supply via two 240 volt bulbs in series. this has worked on several generators over the years and the lights beat against the mains voltage and when the speed is correct to give 50 Hertz the beating stops and the lights stay on or off. It works very well, however when I tried to connect one phase from the Lister to the mains through my two bulb box, the earth leakage trip tripped. I cannot see why this should be unless there is a neutral to earth leak somewhere. A chase around with a meter did not reveal anything that I did not expect but I am wondering if the neutral wire from the alternator should be strapped to the frame and / or run to an earth pole in the outside ground. The incoming mains is earthed by a copper rod below the electric meter.

A small portable single phase generator which is not earthed anywhere but which has an earth wire out just connected to it's chassis, performs perfectly and as I can also test this against the Lister with no problem I have set the little engine as accurately as I can to the mains frequency and then connect this to the Lister set and re-synchronized it. I want to mount the frequency setting facility permanently so I would rather fix the problem.. Would it be better to run an earth wire across the workshop or bang a galvanized earth pole into the ground outside adjacent to the generator. set

What should I do about this tripping, is it an earthing problem or what?
Any comments would be appreciated. By the way I have a very high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen running and is really too good to scrap.

Thanks George.

So much traffic and I am sorry to say that I have had a computer problem and also a domestic one, (two kids moving schools, one to University and the other to 6th. Form College) At the moment the generator is connected earth to earth, neutral to neutral and one phase out of the three on the generator to the one phase in my distribution box. It is a RCD in the mains distribution box and trips when I start the alternator and switch it on.

The 30 HP motor and the 400 Hertz alternator were coupled together on a big frome and provided I think it was a medium sized computer Mainframe, that I was once the resident engineer looking after it. I used to do everything "technical" like installations all sorts of maintenance to just about everthing and I was also told to dispose of kit no longer used. For most people this meant get rid of it and I acquired a stack of useful kit like this, - a hundred or so 2 volt lead acid cells that were time expired, even though they were in excellent condition which I washed out, sealed and boxed up and sent back to UK when I came on leave. Most years I used to send a big crate home, weighing several tons and then hired a lorry to pick them up at Felixstowe.

I do not know what device it was that required 400 Hz at 22 Kw, as this came from another center up the road that I had little to do with, but I got the job of taking it out and getting rid of it. One machine we had was driven by a 65 Kw diesel generator and I ended up with this alternator too, It is standard three phase and a quality product. There are a few pictures of this on my website in the Old Engines section in Part two as I had some problems getting it to excite. www.maribelecosystems.co.uk.

Incidentaly I did not like Sulphuric acid much and in the search for a less dangerous electrolyte I found out that lead acid cells can be filled with an Alum solution with very little change in the characteristics Alum or Aluminum Sulphate is used in large crystal form as an underarm deodorant so indication that it is less harmful than sulphuric! Idealy the cells should be thoroughly washed out before the change, but apart from a slight lowering of the cell voltage the work OK.

Regards George.