[R D S[_2_]]

Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What's the solution?
Bypass the CU and put it on a fused switch?

[A.Lee]

R D S wrote:

Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What's the solution?
Bypass the CU and put it on a fused switch?

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?

It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.

Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.

[R D S[_2_]]

On 17/11/2011 19:48, A.Lee wrote:
R D wrote:

Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What's the solution?
Bypass the CU and put it on a fused switch?

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

[A.Lee]

R D S wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:
Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i wouldnt be
surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he knows
what the cables are etc, and could fit a C type MCB if he thinks it is
suitable.
Alan
--
To reply by e-mail, change the ' + ' to 'plus'.

[John Rumm]

On 17/11/2011 19:41, R D S wrote:

Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What is the rating on the breaker (I take it you mean a MCB and not the
RCD)?

What is the machine?

Induction motors in particular are renowned for drawing a high inrush
current (5 to 9 times the normal rating). Ordinary B type breakers will
typically enter the instant part of their trip curve on 5x current.
Hence unless there is substantial headroom (e.g. 10A motor on 32A MCB)
its quite possible to get a trip.

What's the solution?

If the MCB is dedicated to the machine, then fit a Type C response curve
breaker for it.

Bypass the CU and put it on a fused switch?

Possibly, or a HRC fuse carrier in place of the MCB.



--
Cheers,

John.

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

[Dave Liquorice[_3_]]

On Thu, 17 Nov 2011 20:05:56 +0000, R D S wrote:

The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

Rating plates are normally their running consumption, though can be a
bit loose in the defintion. What is the machine? 14A is only about
3kW, the inrush would be 3 or 4 times that.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

16A would imply a spur rather than a ring. What sort of circuit is
this?

--
Cheers
Dave.

[R D S[_2_]]

On 17/11/2011 20:33, A.Lee wrote:
R D wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:
Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i wouldnt be
surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he knows
what the cables are etc, and could fit a C type MCB if he thinks it is
suitable.
Alan

The sparky merely scratched his head while the breaker kept tripping and
told my landlord that we had too much equipment and that we were
overloading the circuit. (All of the other equipment was idle)

I unplugged everything else and demonstrated that it was this one piece
of equipment causing the problem. The sparky then said it was because
the machine is old.

I argued that a new machine would work in exactly the same and would
cost £16k so we needed to get it working. It ended up with a blistering
row between my landlord and myself because the sparky has convinced him
that I am somehow using his electrics inappropriately.

Another instance where I am sorry that a 'professional' was involved.

[The Natural Philosopher[_2_]]

R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:
R D wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:
Our landlord has had a consumer unit fitted in place of a fusebox
at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the
relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are
fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i wouldnt be
surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he knows
what the cables are etc, and could fit a C type MCB if he thinks it is
suitable.
Alan

The sparky merely scratched his head while the breaker kept tripping and
told my landlord that we had too much equipment and that we were
overloading the circuit. (All of the other equipment was idle)

I unplugged everything else and demonstrated that it was this one piece
of equipment causing the problem. The sparky then said it was because
the machine is old.

I argued that a new machine would work in exactly the same and would
cost £16k so we needed to get it working. It ended up with a blistering
row between my landlord and myself because the sparky has convinced him
that I am somehow using his electrics inappropriately.

Another instance where I am sorry that a 'professional' was involved.

startup current on a big motor is up to 10 times the running current.

rewire with cooker cable and a 45A slow blow cutout..

Some motors have a resistor in series that gets shorted by a centrifugal
switch to limit startup current. Others have 'slow start' using PWM
power to the motor.

[R D S[_2_]]

On 17/11/2011 20:57, Dave Liquorice wrote:
On Thu, 17 Nov 2011 20:05:56 +0000, R D S wrote:

The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

Rating plates are normally their running consumption, though can be a
bit loose in the defintion. What is the machine? 14A is only about
3kW, the inrush would be 3 or 4 times that.

It's one of these,
http://www.opticalmachinery.com/506r.html
I can't find any technichal spec on them but they have 2 motors so I
guess that 14A would be if both were running.


I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

16A would imply a spur rather than a ring. What sort of circuit is
this?

Couldn't tell you. It's in a basement under a shop, I had assumed it was
on the ring but it might be a spur.

[NT[_2_]]

On Nov 17, 9:02*pm, R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:



R D *wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D * wrote:
Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.

[John Williamson]

R D S wrote:
On 17/11/2011 20:57, Dave Liquorice wrote:
On Thu, 17 Nov 2011 20:05:56 +0000, R D S wrote:

The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

Rating plates are normally their running consumption, though can be a
bit loose in the defintion. What is the machine? 14A is only about
3kW, the inrush would be 3 or 4 times that.

It's one of these,
http://www.opticalmachinery.com/506r.html
I can't find any technichal spec on them but they have 2 motors so I
guess that 14A would be if both were running.


I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

16A would imply a spur rather than a ring. What sort of circuit is
this?

Couldn't tell you. It's in a basement under a shop, I had assumed it was
on the ring but it might be a spur.

I know it's an outside chance, but all the references to that machine on
the first few pages of Google hits include prices in US Dollars and/or
shipping from there. As this is a UK group, presumably you are in the
UK, so are the motors UK or USA spec? 60Hz motors often don't like 50Hz
and vice versa, even if the voltages match. It's even more fun if, for
some reason, the motors are for 110 Volts. Has the machine worked
satisfactorily in the UK previously?

--
Tciao for Now!

John.

[R D S[_2_]]

On 17/11/2011 21:24, John Williamson wrote:
R D S wrote:
On 17/11/2011 20:57, Dave Liquorice wrote:
On Thu, 17 Nov 2011 20:05:56 +0000, R D S wrote:

The machine has a plate on it stating 14 amp. I assume that is the
start
up current, I would be very surprised if it drew that while running.

Rating plates are normally their running consumption, though can be a
bit loose in the defintion. What is the machine? 14A is only about
3kW, the inrush would be 3 or 4 times that.

It's one of these,
http://www.opticalmachinery.com/506r.html
I can't find any technichal spec on them but they have 2 motors so I
guess that 14A would be if both were running.


I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

16A would imply a spur rather than a ring. What sort of circuit is
this?

Couldn't tell you. It's in a basement under a shop, I had assumed it
was on the ring but it might be a spur.

I know it's an outside chance, but all the references to that machine on
the first few pages of Google hits include prices in US Dollars and/or
shipping from there. As this is a UK group, presumably you are in the
UK, so are the motors UK or USA spec? 60Hz motors often don't like 50Hz
and vice versa, even if the voltages match. It's even more fun if, for
some reason, the motors are for 110 Volts. Has the machine worked
satisfactorily in the UK previously?

I'm in the UK.

I know that the machine is made for the wrong frequency but it has been
in use in the UK now on a consumer unit at our previous premises for
approx 3 years and for 3 years since at our current place for 3.5 years.

[Tim Watts[_2_]]

Dave Plowman (News) wrote:

In article ,
R D S wrote:
The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

As been said, have the breaker changed to a 'C' type one. Might have to be
ordered - not every wholesaler keeps them in stock.


Worth noting, for general wibbling only, that there is also a type D
breaker, which is even more tolerant. However, it also requires an extremely
low phase-earth impedance to meet disconnection times and it's quite
difficult to meet those requirements in a domestic setting.

I have seen a type D used in one situation only - computer room 32A circuits
where a rack full of UPSes and machines starting at once took out the type C
previously fitted. In that particular case, the substation transformer was
just behind the building and the 600A distribution board where the breaker
was about 15m from the load. And the earthing conductor to the substation
was a bit of nearly inch thick green/yellow wire

--
Tim Watts

[ARWadsworth]

R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:
R D wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:
Our landlord has had a consumer unit fitted in place of a fusebox
at the shop we rent.

One of the machines I use, when starting up, is causing a breaker
to trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the
relevant circuit breaker rated at?
It is likely that it is drawing too much current to start up the
motor. A change to a 'C' type MCB may work (usually B type
breakers are fitted, the C allows a bigger current to be drawn for
a short time), or if the cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the
start up current, I would be very surprised if it drew that while
running. I think the breaker is 16 amp but i'm not 100% (i'm at hone
right
now) that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i
wouldnt be surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he
knows what the cables are etc, and could fit a C type MCB if he
thinks it is suitable.
Alan

The sparky merely scratched his head while the breaker kept tripping
and told my landlord that we had too much equipment and that we were
overloading the circuit. (All of the other equipment was idle)

I unplugged everything else and demonstrated that it was this one
piece of equipment causing the problem. The sparky then said it was
because the machine is old.

I argued that a new machine would work in exactly the same and would
cost £16k so we needed to get it working. It ended up with a
blistering row between my landlord and myself because the sparky has
convinced him that I am somehow using his electrics inappropriately.

Another instance where I am sorry that a 'professional' was involved.

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work out
of you can safely use a C type breaker on that circuit, or indeed a 20A MCB
or a 20A C type MCB to stop the tripping.

I am afraid that you cannot just swap the MCB to a C type without doing some
measurements which of course the sparky should be able to do - assuming that
he is a sparky and not a drinking pal of the landlords.

If you have access to the installation certificate that was issued with the
CU swap then we can tell you what breaker you can use:-)

--
Adam

[ARWadsworth]

Tim Watts wrote:
Dave Plowman (News) wrote:

In article ,
R D S wrote:
The machine has a plate on it stating 14 amp. I assume that is the
start up current, I would be very surprised if it drew that while
running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right
now) that doesn't sound like much.

As been said, have the breaker changed to a 'C' type one. Might have
to be ordered - not every wholesaler keeps them in stock.


Worth noting, for general wibbling only, that there is also a type D
breaker, which is even more tolerant. However, it also requires an
extremely low phase-earth impedance to meet disconnection times and
it's quite difficult to meet those requirements in a domestic setting.

I have seen a type D used in one situation only - computer room 32A
circuits where a rack full of UPSes and machines starting at once
took out the type C previously fitted. In that particular case, the
substation transformer was just behind the building and the 600A
distribution board where the breaker was about 15m from the load. And
the earthing conductor to the substation was a bit of nearly inch
thick green/yellow wire

I saw a 20A D type on a lighting circuit at a recently rewired dance studio.
It had been used as there were far too many fluorecents on the circuit. I
had quoted for that rewire but would not come down by £300 so they used a
different guy. I was called in to sort his mess out and it cost them more
than £300 for me to do so.

--
Adam

[NT[_2_]]

On Nov 18, 7:28*am, Tim Watts wrote:
Dave Plowman (News) wrote:
In article ,
* *R D S wrote:
The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

As been said, have the breaker changed to a 'C' type one. Might have to be
ordered - not every wholesaler keeps them in stock.

Worth noting, for general wibbling only, that there is also a type D
breaker, which is even more tolerant. However, it also requires an extremely
low phase-earth impedance to meet disconnection times and it's quite
difficult to meet those requirements in a domestic setting.

I have seen a type D used in one situation only - computer room 32A circuits
where a rack full of UPSes and machines starting at once took out the type C
previously fitted. In that particular case, the substation transformer was
just behind the building and the 600A distribution board where the breaker
was about 15m from the load. And the earthing conductor to the substation
was a bit of nearly inch thick green/yellow wire

Type C, type D and fuse are all good options, though I couldnt
guarantee a C would be slow enough to work. I'd pick the fuse simply
because its a lot more tolerant of startup current than a C type
breaker.

Replacement is simple enough. However, if you do decide you dont want
to do this for some reason, another option is to start the machine
with a series current limiter, then switch the limiter out. Better to
avoid automated starts if you do this, as it makes motor stall
possible.

Bear in mind your 14A rating will no longer apply at 50Hz, the motor
will draw more when running, somewhere upto 16.8A. This wont be a
probem for a 15/16A fuse/breaker in that that wont trip it. It may all
be clearer if you look up some trip curves for type B&C breakers and
wire fuses.

In theory you could probably fix the CU problem and take it out of the
rent. But running a 17A load on what could be argued as being a 15A
circuit could leave you on less certain ground in negotiating terms,
even if its a nonissue in real terms.


NT

[Martin Brown]

On 17/11/2011 21:35, R D S wrote:
On 17/11/2011 21:24, John Williamson wrote:
R D S wrote:
On 17/11/2011 20:57, Dave Liquorice wrote:
On Thu, 17 Nov 2011 20:05:56 +0000, R D S wrote:

The machine has a plate on it stating 14 amp. I assume that is the
start
up current, I would be very surprised if it drew that while running.

Rating plates are normally their running consumption, though can be a
bit loose in the defintion. What is the machine? 14A is only about
3kW, the inrush would be 3 or 4 times that.

It's one of these,
http://www.opticalmachinery.com/506r.html
I can't find any technichal spec on them but they have 2 motors so I
guess that 14A would be if both were running.


I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.

16A would imply a spur rather than a ring. What sort of circuit is
this?

Couldn't tell you. It's in a basement under a shop, I had assumed it
was on the ring but it might be a spur.

I know it's an outside chance, but all the references to that machine on
the first few pages of Google hits include prices in US Dollars and/or
shipping from there. As this is a UK group, presumably you are in the
UK, so are the motors UK or USA spec? 60Hz motors often don't like 50Hz
and vice versa, even if the voltages match. It's even more fun if, for
some reason, the motors are for 110 Volts. Has the machine worked
satisfactorily in the UK previously?

I'm in the UK.

I know that the machine is made for the wrong frequency but it has been
in use in the UK now on a consumer unit at our previous premises for
approx 3 years and for 3 years since at our current place for 3.5 years.

That is a potential fire risk. A US AC motor designed to run on 60Hz
mains when run on 50Hz UK mains will spin slower and draw higher
currents. If that additional current puts any magnetic cores into
saturation then the current can climb rapidly and the whole thing
overheats. That this hasn't happened already suggests that the motor is
somewhat over engineered and can tolerate this abuse. However it does
mean it will be drawing ~20% more current than its nominal rating.

The trip is probably because from a standing start the motor will draw a
very high transient current determined by its DC coil resistance and
then when running 20% more than nominal 14A rating exceeds your 16 amp
breakers limit. Once it is spinning properly the current drawn should
fall to normal operating levels.

It is also possible that this US kit is designed for 220V and is getting
nearer 240V in the UK so current draw could be another 10% higher still.
Best to measure it properly and find a sparks that actually knows what
they are doing. 20A breaker might stand a chance.

Cheap US made Remington mains electric razors were designed to use
mechanical 60Hz resonance which meant that sold in the UK they were next
to useless (usually as Christmas presents - slogan "so good I bought the
company"). Caveat emptor - I bet they are still selling them.

I have known US made colour computer monitors catch fire on UK 50Hz
video refresh rates in the bad old days before Multisync monitors.

--
Regards,
Martin Brown

[R D S[_2_]]

On 18/11/11 08:04, ARWadsworth wrote:

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work out
of you can safely use a C type breaker on that circuit, or indeed a 20A MCB
or a 20A C type MCB to stop the tripping.

So, as I suspected then the landlord has employed some ****wit at the
cheapest price he can find to upgrade the electrics.

Then when the electrician is scratching his head because the mcb is
tripping every time I switch a machine on and muttering about us
overloading the circuit the landlord thinks the way forward is to enter
into a slanging match with me.

That's the thanks you get for being a model tenant for over 3 years.
Time to buy summat methinks, this rental game is for mugs.

FWIW if extra work was needed because of the gear I use i'd be more than
happy to stump up for it myself which I told him when we'd all finished
screaming at each other and I could get a word in edgeways.

I seem to make extremely poor decisions about who I will have dealings
with. Either that or the majority of people are knobheads. Maybe i'm the
knobhead, I can't rule it out.

[cynic]

On Nov 17, 9:02*pm, R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:





R D *wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D * wrote:
Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.

[Dave Plowman (News)]

In article ,
R D S wrote:
I seem to make extremely poor decisions about who I will have dealings
with. Either that or the majority of people are knobheads. Maybe i'm the
knobhead, I can't rule it out.

A pal bought a BFO low voltage chandelier. Had it fitted by an
electrician. Took out the MCB - it had a massive transformer in the base.

The instructions actually said you may need a type C breaker. And
therefore it should be fitted by an electrician. The electrician of course
either didn't read or understand the instructions and told them the
fitting was faulty. When I explained what they meant he refused to fix
things without his full call out charge, etc.

--
*If they arrest the Energizer Bunny, would they charge it with battery? *

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

[NT[_2_]]

On Nov 18, 9:55*am, R D S wrote:
On 18/11/11 08:04, ARWadsworth wrote:



Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work out
of you can safely use a C type breaker on that circuit, or indeed a 20A MCB
or a 20A C type MCB to stop the tripping.

So, as I suspected then the landlord has employed some ****wit at the
cheapest price he can find to upgrade the electrics.

In fairness the landlord doesnt know if the sparky is a knobhead or
not, though its a bit naive to just trust the first opinion that comes
along, especially when it leads to the conclusion that a bunch of work
is needed.

Then when the electrician is scratching his head because the mcb is
tripping every time I switch a machine on and muttering about us
overloading the circuit the landlord thinks the way forward is to enter
into a slanging match with me.

rather unprofessional

That's the thanks you get for being a model tenant for over 3 years.
Time to buy summat methinks, this rental game is for mugs.

FWIW if extra work was needed because of the gear I use i'd be more than
happy to stump up for it myself which I told him when we'd all finished
screaming at each other and I could get a word in edgeways.

I seem to make extremely poor decisions about who I will have dealings
with. Either that or the majority of people are knobheads. Maybe i'm the
knobhead, I can't rule it out.

Sounds like he's been foolish. People are.

You might be able to resolve it by something like...


I'm offended by the way you've chosen to deal with this issue.

I've consulted ------- who confirmed that the type B overcurrent
protection device your contractor fitted has a trip curve that is
unsuitable for the load in use, and that it requires replacing with an
HRC fuse & carrier for the circuit to function corrrectly. This will
cost £quote to do, and since the problem has been introduced entirely
by your own contractors I request that you resolve this at your
expense within --- days. If this is not done I'll have the system put
right and recover the cost of doing so plus the various costs of lost
production time.


NT

[Mike Tomlinson]

In article o.uk, Dave
Liquorice writes

16A would imply a spur rather than a ring.

A radial, not a spur. And if it's wired in 2.5mm T&E I believe a 20A
breaker could be used.

--
(\__/)
(='.'=)
(")_(")

[Jules Richardson]

On Thu, 17 Nov 2011 21:35:38 +0000, R D S wrote:
I know that the machine is made for the wrong frequency but it has been
in use in the UK now on a consumer unit at our previous premises for
approx 3 years and for 3 years since at our current place for 3.5 years.

Is there any possibility of changing the motor (and compensating for the
speed change if needed)?

[jgharston]

R D S wrote:
So, as I suspected then the landlord has employed some ****wit at the
cheapest price he can find to upgrade the electrics.
Then when the electrician is scratching his head because the mcb is
tripping every time I switch a machine on ...

Being non-domestic premises, it's not required to be MCB/RCD
protected, insist on going back to a rewirable fuse consumer unit,
though a quick skim of the faq and wiki don't give me an
appropriate reference.

JGH

[RobertL]

On Nov 18, 9:41*am, Martin Brown
wrote:

It is also possible that this US kit is designed for 220V and is getting
nearer 240V in the UK so current draw could be another 10% higher still.


Presumably it's not designed for 110 Volt like US equipment usually
is.

Robert

[Martin Brown]

On 18/11/2011 16:01, RobertL wrote:
On Nov 18, 9:41 am, Martin
wrote:

It is also possible that this US kit is designed for 220V and is getting
nearer 240V in the UK so current draw could be another 10% higher still.


Presumably it's not designed for 110 Volt like US equipment usually
is.

I think it would have expired with a blue flash and a shower of sparks
long since if it was. Heavy industrial kit like larger power tools and
some domestic aircon tend to be on 220v even in 110 mains countries.

--
Regards,
Martin Brown

[charles]

In article
,
RobertL wrote:
On Nov 18, 9:41 am, Martin Brown
wrote:

It is also possible that this US kit is designed for 220V and is getting
nearer 240V in the UK so current draw could be another 10% higher still.


Presumably it's not designed for 110 Volt like US equipment usually
is.

heavy curent stuff in the USA and Canada tends to use 220v (110v + 110v)

--
From KT24

Using a RISC OS computer running v5.16

[John Williamson]

Martin Brown wrote:
On 18/11/2011 16:01, RobertL wrote:
On Nov 18, 9:41 am, Martin
wrote:

It is also possible that this US kit is designed for 220V and is getting
nearer 240V in the UK so current draw could be another 10% higher still.


Presumably it's not designed for 110 Volt like US equipment usually
is.

I think it would have expired with a blue flash and a shower of sparks
long since if it was. Heavy industrial kit like larger power tools and
some domestic aircon tend to be on 220v even in 110 mains countries.

Until the full info was posted, I saw no indication that this wasn't a
new installation for the machine concerned. It also wouldn't be the
first time someone stuck the wrong voltage label onto a machine.

14A draw as mentioned is within the norm for a 110V machine, is it not?
Say a vacuum cleaner, which I know this isn't.

--
Tciao for Now!

John.

[John Rumm]

On 18/11/2011 12:01, Mike Tomlinson wrote:
In whill.co.uk, Dave
writes

16A would imply a spur rather than a ring.

A radial, not a spur. And if it's wired in 2.5mm T&E I believe a 20A
breaker could be used.

It could, but that might not fix the problem - the inrush could be over
100A and that will trip a B20.

(A C16 breaker has the same magnetic trip response as a B32)

--
Cheers,

John.

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

[robgraham]

On Nov 18, 8:04*am, "ARWadsworth"
wrote:
R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:
R D *wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D * wrote:
Our landlord has had a consumer unit fitted in place of a fusebox
at the shop we rent.

One of the machines I use, when starting up, is causing a breaker
to trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the
relevant circuit breaker rated at?
It is likely that it is drawing too much current to start up the
motor. A change to a 'C' type MCB may work (usually B type
breakers are fitted, the C allows a bigger current to be drawn for
a short time), or if the cabling allows, a bigger rated breaker.

The machine has a plate on it stating 14 amp. I assume that is the
start up current, I would be very surprised if it drew that while
running. I think the breaker is 16 amp but i'm not 100% (i'm at hone
right
now) that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i
wouldnt be surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he
knows what the cables are etc, and could fit a C type MCB if he
thinks it is suitable.
Alan

The sparky merely scratched his head while the breaker kept tripping
and told my landlord that we had too much equipment and that we were
overloading the circuit. (All of the other equipment was idle)

I unplugged everything else and demonstrated that it was this one
piece of equipment causing the problem. The sparky then said it was
because the machine is old.

I argued that a new machine would work in exactly the same and would
cost £16k so we needed to get it working. It ended up with a
blistering row between my landlord and myself because the sparky has
convinced him that I am somehow using his electrics inappropriately.

Another instance where I am sorry that a 'professional' was involved.

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work out
of you can safely use a C type breaker on that circuit, or indeed a 20A MCB
or a 20A C type MCB to stop the tripping.

I am afraid that you cannot just swap the MCB to a C type without doing some
measurements which of course the sparky should be able to do - assuming that
he is a sparky and not a drinking pal of the landlords.

If you have access to the installation certificate that was issued with the
CU swap then we can tell you what breaker you can use:-)

--
Adam

Interesting Adam - why can one just not swap to a C type. My previous
circular saw motor tripped the MCB - it was hard wired onto a 20A trip
- so I just changed it for a C type and have had no more problems.

I assume that the measurements you are talking about is some sort of
current/time profile and with all due respect to most sparkies I'm not
sure that they wouldn't know what that even meant.

Rob

[John Rumm]

On 18/11/2011 23:49, robgraham wrote:
On Nov 18, 8:04 am,
wrote:
R D S wrote:
On 17/11/2011 20:33, A.Lee wrote:
R D wrote:
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:
Our landlord has had a consumer unit fitted in place of a fusebox
at the shop we rent.

One of the machines I use, when starting up, is causing a breaker
to trip. The machine contains little more than a big motor.

What current is the appliance rated at, and what current is the
relevant circuit breaker rated at?
It is likely that it is drawing too much current to start up the
motor. A change to a 'C' type MCB may work (usually B type
breakers are fitted, the C allows a bigger current to be drawn for
a short time), or if the cabling allows, a bigger rated breaker.

The machine has a plate on it stating 14 amp. I assume that is the
start up current, I would be very surprised if it drew that while
running. I think the breaker is 16 amp but i'm not 100% (i'm at hone
right
now) that doesn't sound like much.

Electric motors suck up a lot of current to get started, so i
wouldnt be surprised if that is causing the breaker to trip.
A word with the sparky who installed it is my best advice, as he
knows what the cables are etc, and could fit a C type MCB if he
thinks it is suitable.
Alan

The sparky merely scratched his head while the breaker kept tripping
and told my landlord that we had too much equipment and that we were
overloading the circuit. (All of the other equipment was idle)

I unplugged everything else and demonstrated that it was this one
piece of equipment causing the problem. The sparky then said it was
because the machine is old.

I argued that a new machine would work in exactly the same and would
cost £16k so we needed to get it working. It ended up with a
blistering row between my landlord and myself because the sparky has
convinced him that I am somehow using his electrics inappropriately.

Another instance where I am sorry that a 'professional' was involved.

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work out
of you can safely use a C type breaker on that circuit, or indeed a 20A MCB
or a 20A C type MCB to stop the tripping.

I am afraid that you cannot just swap the MCB to a C type without doing some
measurements which of course the sparky should be able to do - assuming that
he is a sparky and not a drinking pal of the landlords.

If you have access to the installation certificate that was issued with the
CU swap then we can tell you what breaker you can use:-)

--
Adam

Interesting Adam - why can one just not swap to a C type. My previous
circular saw motor tripped the MCB - it was hard wired onto a 20A trip
- so I just changed it for a C type and have had no more problems.

You need to ensure that fault protection is maintained. That means (in
the case of a non RCD circuit) that the earth loop impedance at the
furthest reach of the circuit is low enough to give adequate fault
current to trip the higher threshold breaker on the magnetic part of its
response.

With a RCD protected circuit, then you can ignore the ELI, but still
need to check the similar circumstance with regards to the prospective
short circuit current.

Basically what to make sure that swapping the breaker wont leave you
finding that it now can't clear a line to neutral or line to earth fault
quickly enough to minimise shock risk, and/or to prevent cable damage.

I assume that the measurements you are talking about is some sort of
current/time profile and with all due respect to most sparkies I'm not
sure that they wouldn't know what that even meant.

Most ought to be familiar with ELI and PSCC - even if all they know is
that they are numbers their multifunction tester can give them!




--
Cheers,

John.

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

[ARWadsworth]

robgraham wrote:
If you have access to the installation certificate that was issued
with the CU swap then we can tell you what breaker you can use:-)

--
Adam

Interesting Adam - why can one just not swap to a C type. My previous
circular saw motor tripped the MCB - it was hard wired onto a 20A trip
- so I just changed it for a C type and have had no more problems.

I assume that the measurements you are talking about is some sort of
current/time profile and with all due respect to most sparkies I'm not
sure that they wouldn't know what that even meant.

Rob

As John said. It really is nothing more than a resistance reading at the end
of the circuit.

The resistance needs to be low enough to trip the MCB in the correct time to
prevent shock and cable damage. A C type MCB needs twice the current to pass
than a B type if there is a short circuit so the maximum resistance allowed
at the end of the circuit is half of that allowed for a B type MCB.

http://wiki.diyfaq.org.uk/index.php?...ypes_B.2CC.2CD

It really would be nothing more difficult that plugging a proper tester into
the end of the circuit and pressing the test button to check this resistance
and you then just compare the results with the table on page 103 of the OSG.

John and I (plus quite a few other posters) could do the calculations with a
tape measure and calculator if we knew what sort of a supply it was and
where the cable ran. But I know that we are both far too lazy to do it that
way:-)


--
Adam

[ARWadsworth]

R D S wrote:
On 18/11/11 08:04, ARWadsworth wrote:

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to
work out of you can safely use a C type breaker on that circuit, or
indeed a 20A MCB or a 20A C type MCB to stop the tripping.

So, as I suspected then the landlord has employed some ****wit at the
cheapest price he can find to upgrade the electrics.

Then when the electrician is scratching his head because the mcb is
tripping every time I switch a machine on and muttering about us
overloading the circuit the landlord thinks the way forward is to
enter into a slanging match with me.

That's the thanks you get for being a model tenant for over 3 years.
Time to buy summat methinks, this rental game is for mugs.

The guy could be a part P electrician. That could mean that he got his
certificate out of a cornflakes packet. If he is Part P then his registering
body will have a technical helpline and he should phone them.(no disrespect
to A.Lee who actually does take an interest in his electrics)

FWIW if extra work was needed because of the gear I use i'd be more
than happy to stump up for it myself which I told him when we'd all
finished screaming at each other and I could get a word in edgeways.

Such an easy solution (assuming that you cannot use a C Type MCB).

I seem to make extremely poor decisions about who I will have dealings
with. Either that or the majority of people are knobheads. Maybe i'm
the knobhead, I can't rule it out.

I was going to say that you cannot be a knobhead as you use uk.d-i-y, but
then I remembered so does dennis:-)

email me and I'll give you my telephone number. I'll explain the MCB options
to the landlord or the electrian (who is clearly out of his depth)

--
Adam

[Tim..[_3_]]

"R D S" wrote in message
...
On 17/11/2011 19:48, A.Lee wrote:
R D wrote:

Our landlord has had a consumer unit fitted in place of a fusebox at the
shop we rent.

One of the machines I use, when starting up, is causing a breaker to
trip. The machine contains little more than a big motor.

What's the solution?
Bypass the CU and put it on a fused switch?

What current is the appliance rated at, and what current is the relevant
circuit breaker rated at?
It is likely that it is drawing too much current to start up the motor.
A change to a 'C' type MCB may work (usually B type breakers are fitted,
the C allows a bigger current to be drawn for a short time), or if the
cabling allows, a bigger rated breaker.


The machine has a plate on it stating 14 amp. I assume that is the start
up current, I would be very surprised if it drew that while running.

I think the breaker is 16 amp but i'm not 100% (i'm at hone right now)
that doesn't sound like much.


14A is most likely the run current. Startup current will be at least 2.5x
that. Get a C type 20A breaker installed.

Tim.
..

[Tim Watts[_2_]]

ARWadsworth wrote:


The guy could be a part P electrician. That could mean that he got his
certificate out of a cornflakes packet. If he is Part P then his
registering body will have a technical helpline and he should phone
them.(no disrespect to A.Lee who actually does take an interest in his
electrics)

Yes - I did the cornflake qual just to make the BCO leave me alone. There
was *nothing* about breaker types, not cable types other than T+E, nor much
consideration of outside work.


--
Tim Watts

[ARWadsworth]

Tim Watts wrote:
ARWadsworth wrote:


The guy could be a part P electrician. That could mean that he got
his certificate out of a cornflakes packet. If he is Part P then his
registering body will have a technical helpline and he should phone
them.(no disrespect to A.Lee who actually does take an interest in
his electrics)

Yes - I did the cornflake qual just to make the BCO leave me alone.
There was *nothing* about breaker types, not cable types other than
T+E, nor much consideration of outside work.


The wiki has more info than a Prat P course.

--
Adam

* Sometimes I like to lay in my neighbours garden and pretend to be a
carrot *

[Fredxx[_3_]]

On 18/11/2011 09:55, R D S wrote:
On 18/11/11 08:04, ARWadsworth wrote:

Does not sound like a professional to me.

You are overloading the MCB, however any sparks should be able to work
out
of you can safely use a C type breaker on that circuit, or indeed a
20A MCB
or a 20A C type MCB to stop the tripping.

So, as I suspected then the landlord has employed some ****wit at the
cheapest price he can find to upgrade the electrics.

Then when the electrician is scratching his head because the mcb is
tripping every time I switch a machine on and muttering about us
overloading the circuit the landlord thinks the way forward is to enter
into a slanging match with me.

That's the thanks you get for being a model tenant for over 3 years.
Time to buy summat methinks, this rental game is for mugs.

FWIW if extra work was needed because of the gear I use i'd be more than
happy to stump up for it myself which I told him when we'd all finished
screaming at each other and I could get a word in edgeways.

I seem to make extremely poor decisions about who I will have dealings
with. Either that or the majority of people are knobheads. Maybe i'm the
knobhead, I can't rule it out.

If he's a member of the NICeic, why not ask them to inspect the
installation as not fit for purpose. Before you do so, make sure the
wiring is up to the right CSA. A clamp meter may be hand to measure the
real current taken by the machine.

[John Rumm]

On 19/11/2011 08:34, ARWadsworth wrote:
robgraham wrote:
If you have access to the installation certificate that was issued
with the CU swap then we can tell you what breaker you can use:-)

--
Adam

Interesting Adam - why can one just not swap to a C type. My previous
circular saw motor tripped the MCB - it was hard wired onto a 20A trip
- so I just changed it for a C type and have had no more problems.

I assume that the measurements you are talking about is some sort of
current/time profile and with all due respect to most sparkies I'm not
sure that they wouldn't know what that even meant.

Rob

As John said. It really is nothing more than a resistance reading at the end
of the circuit.

The resistance needs to be low enough to trip the MCB in the correct time to
prevent shock and cable damage. A C type MCB needs twice the current to pass
than a B type if there is a short circuit so the maximum resistance allowed
at the end of the circuit is half of that allowed for a B type MCB.

http://wiki.diyfaq.org.uk/index.php?...ypes_B.2CC.2CD

It really would be nothing more difficult that plugging a proper tester into
the end of the circuit and pressing the test button to check this resistance
and you then just compare the results with the table on page 103 of the OSG.

John and I (plus quite a few other posters) could do the calculations with a
tape measure and calculator if we knew what sort of a supply it was and
where the cable ran. But I know that we are both far too lazy to do it that
way:-)

One of the downsides of not having a non trip ELI tester is that the
distance and resistance method is often easier!


--
Cheers,

John.

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

[R D S[_2_]]

On 19/11/2011 08:44, ARWadsworth wrote:
email me and I'll give you my telephone number. I'll explain the MCB options
to the landlord or the electrian (who is clearly out of his depth)

It's OK. After a discussion with the landlord I doubt the electrician
will be getting any more work from him. He certainly won't be getting
back in our shop.

But cheers, you're a goodun.

[ARWadsworth]

John Rumm wrote:
On 19/11/2011 08:34, ARWadsworth wrote:
robgraham wrote:
If you have access to the installation certificate that was issued
with the CU swap then we can tell you what breaker you can use:-)

--
Adam

Interesting Adam - why can one just not swap to a C type. My
previous circular saw motor tripped the MCB - it was hard wired
onto a 20A trip - so I just changed it for a C type and have had no
more problems. I assume that the measurements you are talking about is
some sort of
current/time profile and with all due respect to most sparkies I'm
not sure that they wouldn't know what that even meant.

Rob

As John said. It really is nothing more than a resistance reading at
the end of the circuit.

The resistance needs to be low enough to trip the MCB in the correct
time to prevent shock and cable damage. A C type MCB needs twice the
current to pass than a B type if there is a short circuit so the
maximum resistance allowed at the end of the circuit is half of that
allowed for a B type MCB.
http://wiki.diyfaq.org.uk/index.php?...ypes_B.2CC.2CD

It really would be nothing more difficult that plugging a proper
tester into the end of the circuit and pressing the test button to
check this resistance and you then just compare the results with the
table on page 103 of the OSG. John and I (plus quite a few other posters)
could do the
calculations with a tape measure and calculator if we knew what sort
of a supply it was and where the cable ran. But I know that we are
both far too lazy to do it that way:-)

One of the downsides of not having a non trip ELI tester is that the
distance and resistance method is often easier!

Bypass the RCD:-)?

I have got to admit I do love my new tester. It has not tripped the RCD yet
(other than on a RCD test). And a double check of the results show that it
is quite accurate on the non trip test.

However after about 30 tests in quick succession the machine does shut down
to allow it to cool.


--
Adam

* Sometimes I like to lay in my neighbours garden and pretend to be a
carrot *