Repeat question 1

[Derek Greving]

So I too have this same screener and am looking for a three phase Jenny to power. I came across a MEP-004a 15 kw near me. Looks like this particular unit is capable of 3 phase but only 416V. Is that correct and if so, will it just run the 460V motor a bit slower? This came up about three years ago in the following thread, which is now closed.

thread237-477338

 

[waross]

Let me Google that for you;

15 kW @ 0.8 power factor, 50/60 Hz, 120/208 V, 240/416 V

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Ohm's law
Not just a good idea;
It's the LAW!

 

[RRaghunath]

You will be able to run a 460V motor on 416V supply provided the reduced torque output at the motor shaft is adequate to drive the connected equipment.
416V is approximately 90% of 460V and generally motors can work at that level of input supply voltage. If the driven equipment demand is large requiring full rated power at 460V, the motor is likely to get overloaded (and trip) when supplied with 416V.

R Raghunath

 

[Derek Greving]

This is the plug for the unit, which made me think it would be a good Jenny to begin with.

The other option I think I would have is running the Jenny a bit past rated to make up for. I keep hearing that these military generators are underrated?

 

[LittleInch]

Speed of your motor is governed by frequency, not volts until you get close to your max power when it can start to slip more and then overheat.

Lower voltage equals less torque but also more amps for the same power load, so your motor heats up more and if run in hot weather at high load might over heat.

Not sure how you run the generator or "Genny" past rated will help you.

From that earlier thread the load was only 2kVA or less and you're buying a 15kVA generator??

Bad move.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Derek Greving]

Please elaborate…bad move? Just in terms of not lining up directly to something closer to 460v?

 

[LittleInch]

Derek,

You haven't stated the power of your motor, but the previous thread had it a < 2kVA.

Running any generator at less than 30% or even 50% of rated power over any sort of time duration leads to poor running, fouling of cylinders if a diesel or inefficient operation of petrol (gasoline) units and is complete overkill unless you've got a whole heap of extra loads.

Of course there is always the issue of starting current, but running at 10 to 20% or so of rated power is not a good move IMHO.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Derek Greving]

 

[LittleInch]

That calculates at 1.35kW with a 15kW generator. Seems a little bit too big?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[waross]

Connect your motor for 380 Volts.
Dial your AVR down to about 395 Volts.
Low load, wet stacking or slobbering; It does or it doesn't.
Some new machines slobber. This may be cured by load banking for a couple of days.
A wet stacking military machine will probably have been run to destruction and been disposed of as scrap.
I have a lot of experience with standby generators.
Many standby machines run for extended times at light loads.
They will be fully loaded in the A/C season and very lightly loaded in cooler weather.
I have had two new machines slobber. Both were cured and are probably still running.
One additional machine was load banked for 5 days at the suppliers insistence to avoid possible wet stacking.
This set was sized to start and run a large motor but would be running at very light load for about 20 hours per day.
Don't worry about slobber.
If it happens then cure it and move on.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Derek Greving]

Thanks all. We’ll see. It happens to be close to me and frankly, I only plan to run this screener as needed. It’s not gonna be like a 8hr a day or 5 day a week thing. Maybe once a month, couple days for a couple hours tops. Thanks again for all the feedback!!