What happens if your generator is too small?

Apr 02, 2007 16 Replies

Lets say I have a Yamaha EF1000 that can put out 9a max. (Which I don't) And lets say my refrigerator draws 13a to start, and 1.5a to run. (Which it does) What will happen if I try to start the fridge off the genny?



I am guessing the generator will simply stall, with no harm to either. Is that right?



Now for the really foolish question... Any way to start the fridge off the undersized generator?


Well, it won't stall. But it will trip the breaker if you try to exceed the designed rating.

The EF1000 is rated at 6.67 amps(800VA) continuous, 8.3 amps(1000VA) surge.

It's just not going to start your fridge w/o assistance, like a sizeable inverter & a battery bank charged from the generator.

Rob

stall or trip breaker, in a very marginal operation it might harm the fridge by continious running undervolt.

wh not get a bigger generator or apartment sized fridge or inverther and run fridge off your vehicles battery with car running.

My money says it will start. Fridg motors take a fraction of a second to get up to speed and the gennie will likely coast right thru it.

Jim

One of a couple things can happen. Might trip the circuit breaker on the generator. But more likely, the thermal overload on the side of the compressor will trip, and then reset after a minute or two. So, the compressor on the refrig will keep trying to start but never quite will start.

A hard start kit for the fridge may help. Some appliance guys (like me!) occasionally use a boost kit for when the starting components of a compressor go bad.

The generator will not stall. The refrigerator will cause a undervoltage problem during startup. Since your generator is close to having enough power the fridge will start, although it will struggle initially.

Speedy Jim wrote in news:licQh.24036$ snipped-for-privacy@newssvr14.news.prodigy.net:

the voltage may sag for a second. Usually there's a peak power limit spec,how much overload it can take and for how long.

So refrigerators have thermal overloads on them that automatically reset? I sent an email to the manufacturer asking about that, but they never replied.

My Honda EU2000 produces 13/16a, but the breaker is 20a. On an overload the engine "pauses". I don't know about the Yamaha, but I figured it was the same.

Yes. They will trip when they get hot by a overcurrent condition. On a frozen compressor this will occur within five seconds or so. It will cool and restart within a minute.

Indeterminate. Depends on too many characteristics of too many devices.

If I had to pick one-and-only-one, I'd bet the cubic inch of air in front of your nose on Jim's outcome.

Max continuous amp ratings are usually in the ballpark.

Surge amp ratings are ???

Skoal, Puddin'

"Life is nothing but a competition to be the criminal rather than the victim." - Bertrand Russell

Then your house will laugh at your small generator and will find a man with a bigger generator.

i

It depends. Is the surge supposed to last 100 milliseconds, 4 weeks, or 24 months?

It may stall. We tried (just for giggles) to run a hobart MIG welder off my troy bilt 2500 watt generator. With the welder turned up to about 3/4 of capacity, pulled the trigger, and it killed the troy bilt engine.

"Steve Barker" wrote in news:HvCdnb233-qWZ4zbnZ2dnUVZ snipped-for-privacy@giganews.com:

One thing to consider;many modern refrigerators have a power-factor controller built in to increase energy efficiency.

How would the underpowered generator affect it?

Historically, refridgerator motors do not play well with brown outs. When you draw more amperage than the source is able to provide, you get a brown out. The voltage will simply start lowering. Many appliances will not function. Some will recieve damage.

"dnoyeB" wrote in news:87KdnepFgPGQrYPbnZ2dnUVZ snipped-for-privacy@comcast.com:

For damage to occur,the "brownout" has to last for some time,while the V drop for a motor startup will only last for a brief time.Probably less than a minute. Motors are pretty durable.

electronics,OTOH....

So,if your fridge has microprocessor controls,then there could be a problem.

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