Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.

On 25/03/2012 16:29, Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.


Induction motor? Start load 6 x running load IIUC?

Happens a lot with pressure washers.

--
Dave - The Medway Handyman www.medwayhandyman.co.uk

The Medway Handyman wrote:
On 25/03/2012 16:29, Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.


Induction motor? Start load 6 x running load IIUC?

can be a lot more than that.

Happens a lot with pressure washers.



--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On Sun, 25 Mar 2012 16:29:20 +0100, Him & Her wrote:

Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.

You could just remove the trip switch.... or preferably fit a less fussy one.

--
http://petersparrots.com
http://petersphotos.com

U2's on-tour sound system weighs 30 tons.

On Sun, 25 Mar 2012 16:29:20 +0100, Him & Her wrote:

Sorry no, nothing to do with girls getting high

Very few females called Genny these days. My Mum was one, though! .-)

--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

It is, and there is not much you can do except maybe have a resistor in
series - a high wattage bulb - and a switch to short it out once the
motor is up to speed.

Another option is the old aircraft trick of a rotary converter where the
inertia of it keeps the voltage up past the surge. But that itself needs
to start up as well..



TIA.




--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On Mar 25, 4:29*pm, "Him & Her" wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.

http://wiki.diyfaq.org.uk/index.php?title=Droppers


NT

On Mar 25, 5:51*pm, NT wrote:
On Mar 25, 4:29*pm, "Him & Her" wrote:

Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.

http://wiki.diyfaq.org.uk/index.php?title=Droppers

NT

Another possibility is to start the load on 110v then switch to 240v.
Especially easy if the gen has both voltage outputs.


NT

On Mon, 26 Mar 2012 03:51:28 -0700 (PDT), NT wrote:

Another possibility is to start the load on 110v then switch to 240v.
Especially easy if the gen has both voltage outputs.

But normally that just switches which socket is live the blue 240 one
or the yellow 110v...

--
Cheers
Dave.

On Mar 26, 1:27*pm, "Dave Liquorice"
wrote:
On Mon, 26 Mar 2012 03:51:28 -0700 (PDT), NT wrote:
Another possibility is to start the load on 110v then switch to 240v.
Especially easy if the gen has both voltage outputs.

But normally that just switches which socket is live the blue 240 one
or the yellow 110v...

.... making it easy to implement


NT

On Mon, 26 Mar 2012 07:14:25 -0700 (PDT), NT wrote:

Another possibility is to start the load on 110v then switch to
240v.
Especially easy if the gen has both voltage outputs.

But normally that just switches which socket is live the blue 240
one
or the yellow 110v...

.... making it easy to implement

Are you suggesting a blue/yellow Y cord? I'd look very closely at the
wiring between the alternator, switch and sockets. One assumes that
the 110/240 adjustment is done by series (240) and parallel (110)
connection of two windings from the alternator.

--
Cheers
Dave.

Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

TIA.


I suppose you could try a 1kW fire element in series; switch it out once
the saw was turning. Or get someone else to. Don't want you losing an arm.

Bill

On 25/03/2012 18:30, Bill Wright wrote:
Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged it
to it.

What (if anything) can I put in line to stop the trip on start up as I
figure it's just that initial surge.

TIA.

I suppose you could try a 1kW fire element in series; switch it out once
the saw was turning. Or get someone else to. Don't want you losing an arm.

Bill
I had a similar issue with a chop saw - it was the mains mcb
that tripped in this case..
Sort of solved by running the saw from a longish (and cheap!) extension
cable reel - seemed to have just enough resistance to give the mcb time
to not drop out. Saw didn't seem to suffer once it was up to speed.

Adrian

"Adrian Brentnall" wrote in message
...
: On 25/03/2012 18:30, Bill Wright wrote:
: I suppose you could try a 1kW fire element in series; switch
it out once
: the saw was turning. Or get someone else to. Don't want you
losing an arm.
Snip
: I had a similar issue with a chop saw - it was the mains mcb
: that tripped in this case..
: Sort of solved by running the saw from a longish (and cheap!)
extension
: cable reel - seemed to have just enough resistance to give the
mcb time
: to not drop out. Saw didn't seem to suffer once it was up to
speed.

Interesting idea that Adrian, will give that a try in a day or
two.

"Bill Wright" wrote in message
...
: Him & Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: TIA.
:
:
: I suppose you could try a 1kW fire element in series; switch it
out once
: the saw was turning. Or get someone else to. Don't want you
losing an arm.

Anything is worth a try although I can't help thinking I'm going
to look a right prat turning on a leccy fire in the middle of a
park

On 25/03/2012 16:29, Him & Her wrote:
Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from
it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

Is it an induction motor saw?

They can take anything from 5 to 9 times the normal full load current on
starting, coupled with the likelihood of it being a non unity power
factor. Hence that 1500W might be at 0.65 PF or similar,

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

Might be interesting to see if the motor starts on its own from the
genny (i.e. assuming its belt drive, then without the belt one). If it
does then some form of belt tensioner that would allow the motor to be
unloaded at startup and then the blade drive engaged.

--
Cheers,

John.

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

"John Rumm" wrote in message
o.uk...
: On 25/03/2012 16:29, Him & Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: Is it an induction motor saw?
:
: They can take anything from 5 to 9 times the normal full load
current on
: starting, coupled with the likelihood of it being a non unity
power
: factor. Hence that 1500W might be at 0.65 PF or similar,
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: Might be interesting to see if the motor starts on its own from
the
: genny (i.e. assuming its belt drive, then without the belt
one). If it
: does then some form of belt tensioner that would allow the
motor to be
: unloaded at startup and then the blade drive engaged.

No belt drive unfortunately

Him & Her wrote:
"John Rumm" wrote in message
o.uk...
: On 25/03/2012 16:29, Him & Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: Is it an induction motor saw?
:
: They can take anything from 5 to 9 times the normal full load
current on
: starting, coupled with the likelihood of it being a non unity
power
: factor. Hence that 1500W might be at 0.65 PF or similar,
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: Might be interesting to see if the motor starts on its own from
the
: genny (i.e. assuming its belt drive, then without the belt
one). If it
: does then some form of belt tensioner that would allow the
motor to be
: unloaded at startup and then the blade drive engaged.

No belt drive unfortunately

There are soft start units available which go between the power source
and the motor, but they're not cheap.

Otherwise, a slower MCB might help, as would a non-inverter generator
with a large flywheel mass.

--
Tciao for Now!

John.

On 25/03/2012 22:27, Him & Her wrote:
"John wrote in message
o.uk...
: On 25/03/2012 16:29, Him& Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: Is it an induction motor saw?
:
: They can take anything from 5 to 9 times the normal full load
current on
: starting, coupled with the likelihood of it being a non unity
power
: factor. Hence that 1500W might be at 0.65 PF or similar,
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: Might be interesting to see if the motor starts on its own from
the
: genny (i.e. assuming its belt drive, then without the belt
one). If it
: does then some form of belt tensioner that would allow the
motor to be
: unloaded at startup and then the blade drive engaged.

No belt drive unfortunately

How loud is the motor when running - quite and smooth like a bit of
machine shop equipment, or screams at you like most hand held power tools?

Failing that, what make/model of saw?

Just trying to work out what sort of motor it actually is... If it *is*
an induction motor, then it would be unusual to have a direct drive. If
its a universal motor then the problem is simpler to solve since the
inrush is less anyway, and a bit of extra resistance in the supply will
often solve the problem.

For example, trying the long extension lead trick mentioned elsewhere
might work. Also with a universal motor, you may find an off the shelf
power tool speed controller can be used to start it on slow and then
ramp it up. Or, you could make a step start box (basically a couple of
relays, a high power resistance of some sort (a traditional light bulb
(or a few in parallel) may pass enough current to get it spinning with
no load), and a second relay that closes after a short time delay to
short out the extra resistor and apply full power to the tool)


--
Cheers,

John.

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

On 26/03/2012 11:41, John Rumm wrote:
On 25/03/2012 22:27, Him & Her wrote:
"John wrote in message
o.uk...
: On 25/03/2012 16:29, Him& Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: Is it an induction motor saw?
:
: They can take anything from 5 to 9 times the normal full load
current on
: starting, coupled with the likelihood of it being a non unity
power
: factor. Hence that 1500W might be at 0.65 PF or similar,
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: Might be interesting to see if the motor starts on its own from
the
: genny (i.e. assuming its belt drive, then without the belt
one). If it
: does then some form of belt tensioner that would allow the
motor to be
: unloaded at startup and then the blade drive engaged.

No belt drive unfortunately

How loud is the motor when running - quite and smooth like a bit of
machine shop equipment, or screams at you like most hand held power tools?

Failing that, what make/model of saw?

Just trying to work out what sort of motor it actually is... If it *is*
an induction motor, then it would be unusual to have a direct drive. If
its a universal motor then the problem is simpler to solve since the
inrush is less anyway, and a bit of extra resistance in the supply will
often solve the problem.

For example, trying the long extension lead trick mentioned elsewhere
might work. Also with a universal motor, you may find an off the shelf
power tool speed controller can be used to start it on slow and then
ramp it up. Or, you could make a step start box (basically a couple of
relays, a high power resistance of some sort (a traditional light bulb
(or a few in parallel) may pass enough current to get it spinning with
no load), and a second relay that closes after a short time delay to
short out the extra resistor and apply full power to the tool)

or, simpler still, a box with switches for on/off and start/run.
Manually set to start, then on. Once running flip the load switch to
run. With a load like a couple of 100W bulbs (i.e. current limit of just
under an amp) you don't need to be too fussy about how long the dummy
load is in circuit - especially if they are in open space and so can cool.


--
Cheers,

John.

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

On 26/03/2012 11:41, John Rumm wrote:
On 25/03/2012 22:27, Him & Her wrote:
"John wrote in message
o.uk...
: On 25/03/2012 16:29, Him& Her wrote:
: Sorry no, nothing to do with girls getting high
:
: Got a 3kva generator and am trying to run a 1500w table saw
from
: it.
:
: Genny trips out on pressing start on the saw. Saw works fine
when
: plugged in to house. Genny been fine with everything else
plugged
: it to it.
:
: Is it an induction motor saw?
:
: They can take anything from 5 to 9 times the normal full load
current on
: starting, coupled with the likelihood of it being a non unity
power
: factor. Hence that 1500W might be at 0.65 PF or similar,
:
: What (if anything) can I put in line to stop the trip on
start up
: as I figure it's just that initial surge.
:
: Might be interesting to see if the motor starts on its own from
the
: genny (i.e. assuming its belt drive, then without the belt
one). If it
: does then some form of belt tensioner that would allow the
motor to be
: unloaded at startup and then the blade drive engaged.

No belt drive unfortunately

How loud is the motor when running - quite and smooth like a bit of
machine shop equipment, or screams at you like most hand held power
tools?

Failing that, what make/model of saw?

Just trying to work out what sort of motor it actually is... If it
*is* an induction motor, then it would be unusual to have a direct
drive. If its a universal motor then the problem is simpler to solve
since the inrush is less anyway, and a bit of extra resistance in the
supply will often solve the problem.

For example, trying the long extension lead trick mentioned elsewhere
might work. Also with a universal motor, you may find an off the shelf
power tool speed controller can be used to start it on slow and then
ramp it up. Or, you could make a step start box (basically a couple of
relays, a high power resistance of some sort (a traditional light bulb
(or a few in parallel) may pass enough current to get it spinning with
no load), and a second relay that closes after a short time delay to
short out the extra resistor and apply full power to the tool)


We had a motor driven sample for use at shows and the speed controller
that the model maker used was a normal light dimmer and a bulb in series
with the motor. It was simple and reliable.
if you got a 3KW element in series with the motor it would not be able
to trip as the load would be resistive.

Must be worth a try.

Gary

: Got a 3kva generator and am trying to run a 1500w table saw
from it.

: Genny trips out on pressing start on the saw. Saw works fine
when plugged in to house. Genny been fine with everything else
plugged it to it.

We had a motor driven sample for use at shows and the speed controller
that the model maker used was a normal light dimmer and a bulb in series
with the motor. It was simple and reliable.
if you got a 3KW element in series with the motor it would not be able to
trip as the load would be resistive.

Must be worth a try.

C'mon, this is a DIY group... take the genny head off the engine, the motor
off the saw, couple the engine to the saw, sorted,

"John Rumm" wrote in message
o.uk...
: On 25/03/2012 22:27, Him & Her wrote:
: "John wrote in message
: o.uk...
: : On 25/03/2012 16:29, Him& Her wrote:
: : Sorry no, nothing to do with girls getting high
: :
: : Got a 3kva generator and am trying to run a 1500w table
saw
: from
: : it.
: :
: : Genny trips out on pressing start on the saw. Saw works
fine
: when
: : plugged in to house. Genny been fine with everything else
: plugged
: : it to it.
: :
: : Is it an induction motor saw?
: :
: : They can take anything from 5 to 9 times the normal full
load
: current on
: : starting, coupled with the likelihood of it being a non
unity
: power
: : factor. Hence that 1500W might be at 0.65 PF or similar,
: :
: : What (if anything) can I put in line to stop the trip on
: start up
: : as I figure it's just that initial surge.
: :
: : Might be interesting to see if the motor starts on its own
from
: the
: : genny (i.e. assuming its belt drive, then without the belt
: one). If it
: : does then some form of belt tensioner that would allow the
: motor to be
: : unloaded at startup and then the blade drive engaged.
:
: No belt drive unfortunately
:
: How loud is the motor when running - quite and smooth like a
bit of
: machine shop equipment, or screams at you like most hand held
power tools?

Hmm, I'd say she's a bit of a screamer, the saw is quite noisy
too

: Failing that, what make/model of saw?

Nowt special, a NuTool HS1500. Having said that, it does a good
job, just not when attached to the genny.

Blade just bolts straight on to the motor. Was the same on a
Performance Pro table saw I had.

: Just trying to work out what sort of motor it actually is... If
it *is*
: an induction motor, then it would be unusual to have a direct
drive. If
: its a universal motor then the problem is simpler to solve
since the
: inrush is less anyway, and a bit of extra resistance in the
supply will
: often solve the problem.
:
: For example, trying the long extension lead trick mentioned
elsewhere
: might work. Also with a universal motor, you may find an off
the shelf
: power tool speed controller can be used to start it on slow and
then
: ramp it up. Or, you could make a step start box (basically a
couple of
: relays, a high power resistance of some sort (a traditional
light bulb
: (or a few in parallel) may pass enough current to get it
spinning with
: no load), and a second relay that closes after a short time
delay to
: short out the extra resistor and apply full power to the tool)

Just tried a 10m extension, didn't seem to make any difference

On 26/03/2012 14:53, Him & Her wrote:

: How loud is the motor when running - quite and smooth like a
bit of
: machine shop equipment, or screams at you like most hand held
power tools?

Hmm, I'd say she's a bit of a screamer, the saw is quite noisy
too

: Failing that, what make/model of saw?

Nowt special, a NuTool HS1500. Having said that, it does a good
job, just not when attached to the genny.

Right ok, forget all the induction motor stuff, this is a universal
motor jobbie.

Blade just bolts straight on to the motor. Was the same on a
Performance Pro table saw I had.

Yup, I have something similar on the shelf (does not get much use since
I get a unisaw, but kept since it is transportable)

And yup, its loud!

: For example, trying the long extension lead trick mentioned
elsewhere

Just tried a 10m extension, didn't seem to make any difference

Worth a try, but probably not enough resistance for this application. I
would expect the universal motor probably pulls two to three times full
current at startup (they usually start with a "bang" as they delivery
maximum torque from stalled, and least torque when running (the opposite
of what you want in a saw really, but that is another matter!))

If you add more permanent resistance inline with it then you will
probably reduce the performance. I would be inclined to try a quick
lashup with a batten holder and a 100W light bulb inline with its supply
- see if firstly that will get it spinning at a decent speed with no
load, then secondly if the genny will hack it. If it does you can make
something more "elegant" to allow a two stage start.


--
Cheers,

John.

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

Him & Her wrote:

Sorry no, nothing to do with girls getting high

Got a 3kva generator and am trying to run a 1500w table saw from it.

Genny trips out on pressing start on the saw. Saw works fine when
plugged in to house. Genny been fine with everything else plugged
it to it.

What (if anything) can I put in line to stop the trip on start up
as I figure it's just that initial surge.

The only fix is to have a much bigger generator.