MEP-006 motor starting max? What can your generator power?

[bimota]

Any push an MEP-006 to see how many horsepower water pump one will start?

 

[R Racing]

I'd guess a 40 to 50 hp motor.

 

[Suprman]

Depends on the condition of the gen. With everything operating as intended injectors ip filters strong engine it should run at least 70kw. If it's not in tip top shape you won't get as much power out of it. Running at 440v you should be able to get 160 amps. That should start a pretty big motor.

 

[Isaac-1]

Do you have the specs on the motor you are wanting to start, does it start direct on line, or does it have some type of soft start system, etc? When you get into motors in this size range there are a lot of variables.

 

[wciguy]

The 006a is rated to start a 20 HP 3 phase motor. It will run closer to an 80 HP motor, but the starting amps is the killer and what limits it.

 

[bimota]

The 006a is rated to start a 20 HP 3 phase motor. It will run closer to an 80 HP motor, but the starting amps is the killer and what limits it.

wciguy - Can you tell us the source for your 20hp rating?

Seems small - the mil surplus reverse osmosis machine I stripped down had a 20hp pump and was mounted with an MEP-005. Though if you do the basic math - 60,000 watts divided by 746 watts per horsepower = 80HP and electrical output of diesel powered generator say 35% efficiency, the net equals 28hp. So a 20hp rating would be very conservative.

Any idea what is the limiting factor - inrush current on the electric circuit breaker perhaps? Does anyone know the actual circuit breaker setting for the -004, -005 and -006 since they use the same circuit breaker the actual trip current would need to be set somewhere. They would set the breaker to trip prior to frying something inside but they also might have a delay for inrush current - can anyone detail the electric circuit breaker verification or adjustment process?

Also - what do you do with all those generators wciguy?

 

[wciguy]

bimota - I stand corrected - - another victim of CRS disease. I had to do some digging since it has been a while since I originally found the info and my fuzzy memory had it all wrong.

"4.3.7 Motor Starting Capability. The Class 1 (precise) 15-200 kW dieselengine-driven generator sets are capable of across-the-line starting of a motor
rated at one horsepower per kW of set kW rating. The class 2 (utility) 15-200
kW diesel engine-driven generator sets are capable of across-the-line starting
of a motor rated at one horsepower per 1-1/2 kW of set kW rating. The starting
current rating of the motor is NEMA Code F and the motor being loaded with a
flywheel having the inertia equal to that of the motor. Starting is defined as
acceleration of the motor to rated speed without tripping any safety device."

Taken from MIL-STD-633E. Apparently not a "standard" anymore, though.

"NOTE: MIL-STD-633E has been redesignated
as a handbook, and is to be used for guidance MIL-HDBK-633
purposes only. This document is no longer to be 20 FEBRUARY 1998
cited as a requirement. For administrative expediency,
the only physical change from MIL-STD-633E is this
cover page. However, this document is no longer to be
cited as a requirement. If cited as a requirement,
contractors may disregard the requirements of this
document and interpret its contents only as guidance."

Also note this does not include the smaller sets(below 15KW).

My machine shop is full of 3-phase equipment, so I will have to test this info at some point. I did this at one point with a good running 005a. It would start my 10 HP air compressor, but not my 25 HP Lucas boring mill or my 15 HP Monarch Lathe. The circuit breaker tripped on both of them. Think it saw the large starting current as a short because it tripped immediately.

My 75KW load bank was originally set up for 400hz service. I replaced the six cooling fans with 60hz models. It has three separate resistance loads available, two 20KWs and one 35KW, which can be applied in any combination, so I can load to 20KW, 35KW, 40KW, 55KW, or 75KW. Make one **** of a good space heater at 75KW!!

Also have electric space heaters for checking the smaller units, 4KW (x2) and one 5KW.

Have not messed with the 180KW load bank yet. As I get the 007 gensets going, I will need it, though.

The generators I have are ones still in my inventory of units for sale, except for the lone 003a. Think I will keep this one.
The 007 units have been a disappointment. Getting coolant in the oil on 2 out of the 3 I have checked out so far. Have had the same problem with most of the 006a units I have had. Not buying any more 006a or 007a set for this reason. Have had very good luck with the 002a, 003a, 004a, and 005a gensets and I really like the 805a and 806a sets. The John Deere engines are awesome. Have seen 55KW from an 805a!

You need to redo your math on the RO machine. Using 30,000 watts instead of 60,000, unless that generator is a 006a.

This is a really useful thread. Thanks to all the participants.