Starting 3-ph motors w/003A

[bsorcs]

Having read many of the extremely informative genset threads, I think that I might be able to start/run all of my 3-ph machinery using a 003A.

Items of concern are:
1-~1923 GE squirrell-cage 5hp 220V/???a induction motor [12" jointer] ;
2-~1974 Reuland 7.5 hp 208/220/410V//21.2/20/10a motor [24" planer].

I have no idea what the inrush currents on these might be, but I'd bet that they are substantial. I sent emails to Reuland and GE.

Will the 003A start and run the two, individually, unloaded, given the 120/208 3ph capacity

EDIT: Same question re 5kw sets?

 

[Keith_J]

Easily. Inrush is the response to inertia, the 003a has a huge rotor permanently coupled to that 140 cubic inch Onan diesel. There are two huge flywheels on this engine, all of which will power through the inrush. As long as the equipment powered by the motors isn't loaded!!

The only issue would be temperature, keep the generator in a well ventilated enclosure, shielded from the sun and it will start either one without issue. The three phase load will be easier, simply because it will have a higher power factor on startup.

Now I wouldn't try either motor with a consumer grade 10 kW generator. The 003a would be rated a 15 kW by the same standards the consumer grade generators are rated.

 

[Triple Jim]

A recent thread points out that the breaker on the 003A may or may not hold when starting big motors. I pretty much concluded that if the fluid-delay type breaker seems to trip too quickly, that is, not enough time delay, it may be defective and need replacement.

My 003A starts the industrial 5HP single phase 1725 rpm motor driving my air compressor OK while supplying the loads around the rest of the house.

 

[Keith_J]

The breakers on the 002/003a units are adjustable. It is possible some units may be out of adjustment. Breakers protect wiring from shorts, an 003 should be able to start an unloaded 10 hp three phase motor without tripping breakers. Most tools start unloaded, even air compressors. Air conditioning compressors are an exception but they usually have suction pressure equal to discharge, meaning they are unloaded. Most air conditioning thermostats have restart protection to prevent restart 2-5 minutes after stopping to allow pressure to equalize.

 

[rosco]

My 003 trips the breaker on my 5 hp, 1 ph, compressor. Are adjustment procedures for breakers in the TM, or is that not wide spread info. I never thought to look, but will tomorrow when I get to the shop. Thanks

 

[Keith_J]

Variable resistor 3 labeled R3 adjusts the relay circuit which trips the main breaker CB1. Adjustment is covered in the -34 manual.

A 5 hp compressor on 240 volts should not trip CB1 on a MEP 003a. That is less than 20 amps running, the generator will drive 50+ amperes constant.

Also, check the unloader on the compressor. Inrush will be much higher if the unloader isn't working. When the compressor cycles off, you should hear air escaping from the line between the check valve and last stage. Usually, this is done by a small Schrader valve at the pressure switch.

Finally, if the motor capacitors are faulty, they will drastically increase the inrush current.

 

[glcaines]

I routinely power my Delta 5 HP table saw which is 3 PH and my 5 HP radial saw. Never a problem. I've also occasionally powered a 5 HP 3 Ph compressor. Again, no problems.

 

[Triple Jim]

Here's the previous thread I posted about ^. http://www.steelsoldiers.com/auxiliary-equipment/61257-mep-002a-003a-main-breaker.html

It's long, but some of the points covered were that some MEPs have the problem and some of the same model don't, adjusting the breaker to spec did not help with starting large motors, and the breaker uses fluid to create a mechanical time delay, so if the fluid were lost over the years somehow, the breaker would effectively be a non time delay type. The whole thread is worth reading.

The main breaker is made by Heinemann, and here's the document from Speddmon's post about its operation:
Breaker Theory.pdf

 

[rosco]

Super.... Thanks (I know abourt the unloader, thanks)... Super Generators

 

[bsorcs]

Yep. That's the thread that finally led me to think an 003 could haul the freight. I never cease to be amazed at the caliber and volume of info here and in the deuce forum. Hats off!

 

[bsorcs]

Same starting question, but using MEP-002A?