Generator size to start motor

[Cord]

I have an ejector pump with a 2hp 1/230v motor that draws 13.9 amps and has a recommended breaker size of 20 amps. My 3,000 watt, .8pf generator is rated for 16a/240v. Even with no load on the motor, the generator will not start the motor; it instantly goes to overload and shuts down. I understand the inrush needs to of a motor are greater than it's running amps, but this motor is currently unloaded as we're testing it dry. Assuming the motor is wired correctly, what size generator would be needed to start the motor?

 

[coldsteelva]

Potentially 19.9amps, thus a 20amp breaker - do they make a Kill-A-Watt meter that can plug inline and record the max start pull?

EDIT: Can you post or Google the mfr make model

 

[Soundguy]

If the pump reccomends a 20a breaker, then you can bet that it's max draw is no more than about 25ish amps for a very, very, very short time, otherwise the 20a breaker would pop.

I generally like a generator to be RATED for 2X motor RUN for good starts. Now.. the genny should have a higher 'start' number than it's rated number. For instance.. you see a 6500w rated genny that will do 8500 for starts, etc. That';s on good clean motors.

I've seen some old haggard motors that needed 3X run for starting.. seeing fewer and fewer of those nowadays.

 

[buickanddeere]

Doing a hard start upgrade by making the start capacitor 3 to 5 times larger . Depends if the generator had a real voltage regulator or a peice if crap cheapo bridge rectifier .
7500Watt running maybe able to limp it over but I would go with this.8W/1W Dual Fuel Generator, 459cc - Champion Power Equipment

 

[buickanddeere]

Just because a 2X larger generator usually limps the motor up to speed , after several seconds of wide open governors, dim lights from low voltage and 10 seconds up to speed instead of 2 seconds, doesn't mean you should .
Generators are cheap now compared to the 1999 Y2K prices. Buy what is needed instead of barely enough.
I'll look at the code book but iirc that 20 FLA motor requires a 30 amp breaker and at least 12 gauge wire .

 

[buickanddeere]

Most of the time when something gets broken, burned out or wrecked . The operator was trying to make do with something too small doing too large of a task. 92W/115W Electric Start Portable Generator, 459cc - Champion Power Equipment

 

[Cord]

I attached a cut sheet for the pump. Remember, at this time I'm only trying to start this with no load so I can prove it's functional to the inspector.

The generator that I initially tried to test it on was a MEP-831a. It's a very nice inverter unit, but it's very sensitive to an overload.

For testing, I have a 6,500 cont / 7500 surge generator reserved from a rental house. I wanted a 10k unit, but it wasn't available. I'm concerned the 6.5k won't be enough.

The permanent generator will be a Onan DJB 6k diesel unit.

 

[HarryVanderpool]

We have a 2hp submersible 300' down our well. 230v
In 1994 we bought a bare-bones Generac 5000 watt generator.
When we have extended power outages, which we have had many,sometimes 3 and 4 days, we run the generator 3 hours in the morning and 4 in the evening.
When the well kicks on, the generator lets out a momentary bark and runs very smoothly.
No problems with this set-up in 23 years. Never even changed the spark plug.
Yearly filled with stabilized gas and always turn the valve off and run the carb dry prior to storage.
ALWAYS starts on the first pull.
We never run it unless a power outage.

 

[buickanddeere]

Depends what other loads the 6Kw diesel is carrying when the 2HP pump starts . I have started a 3/4HP 240V deep well pump with a 5000 watt Honda and it's plenty for that generator. A 2HP deep well start on 5000watt will be very slow and at brownout voltage if it starts at all. Sure that isn't a 1/2HP instead of 2HP ?

 

[HarryVanderpool]

1/2hp 300' down would be a very bad idea; don't you think?