Sump pump amps exceed generator capacity - what happens?

[NAC]

So, I bought a cheap generator in case we lose power and my basement starts flooding (again). BUT, I went too cheap and got one rated 800/900 watts.

My sump pump is rated 9.4 amps * 115 vols = 1100 watts.

So what will happen if I connect the two? I don't plan on connecting anything else to the generator.

I would hope that the pump will just be running at less than full capacity because it isn't recieving enough power. Or would the generator or pump be damaged?

In the future I'll buy a better generator, but that isn't an option right now...

 

[IronWing]

Everything catches fire but then the rising water puts it out so it's all good.

 

[LennyZ]

You won't be pumping water for long.
The breaker will trip and stop the pump.

 

[NAC]

Follow up question since this doesn't make sense to me:

I have two Zoeller pumps:
They are both at 5 feet head.
Model 57 which is rated at about 160 gallons per minute, 1/3 HP, 9.7 amps
Model 98 which is about 300 gallons per minute, 1/2 HP, 9.4 amps

Why would the less powerful unit draw more power?

 

[NAC]

Ack. Thanks LennyZ. That wont be good.
I wonder if Zoeller is very conservative in the amps rating.

 

[Markbnj]

AFAIK the generator will have a circuit breaker that will pop if the load exceeds the unit's output. And since one blow-dryer will exceed that unit's output I think you can count on that happening if you switch on either of those pumps.

 

[z1ggy]

Yep your breaker will go off if you hook that pump up to it. Any chance you could run the pump at less then it's rated power?

Jw, why did you go with such a cheap gen? @ 220v it's only going to be putting out 4A or so.

 

[olds]

Never go cheap. Overbuild EVERYTHING.

 

[BoomerD]

Never go cheap. Overbuild EVERYTHING.

It's better to have more than you need...and not need it than the opposite.

ALWAYS over-build/over-engineer.

 

[3chordcharlie]

Going with less than 15/20A (i.e. 'one full home circuit') on a generator means one ordinary tool/appliance is potentially capable of overloading it.

Seems like a problem to me.

 

[Mark R]

Not only that, but pumps take a big surge - typically around 10x their normal current during start up.

This can be a big problem with small generators - when a pump kicks in, even though the generator might be 3 or 4x the pump rating, the switch on surge from the pump can still stall the generator.

 

[waggy]

Never go cheap. Overbuild EVERYTHING.

yeah and when it comes to sump pumps? always go overboard...

 

[deadlyapp]

Follow up question since this doesn't make sense to me:

I have two Zoeller pumps:
They are both at 5 feet head.
Model 57 which is rated at about 160 gallons per minute, 1/3 HP, 9.7 amps
Model 98 which is about 300 gallons per minute, 1/2 HP, 9.4 amps

Why would the less powerful unit draw more power?

Depending on how the pump was designed it may not be a very efficient design. keeping the head the same and increasing the flowrate so significantly affects the hydraulic design a lot.

 

[JohnOfSheffield]

So, I bought a cheap generator in case we lose power and my basement starts flooding (again). BUT, I went too cheap and got one rated 800/900 watts.

My sump pump is rated 9.4 amps * 115 vols = 1100 watts.

So what will happen if I connect the two? I don't plan on connecting anything else to the generator.

I would hope that the pump will just be running at less than full capacity because it isn't recieving enough power. Or would the generator or pump be damaged?

In the future I'll buy a better generator, but that isn't an option right now...

Depends, there are two types of cheap.

Cheap and underpowered, it won't deliver more power than it's rated at.
Cheap and dangerous, it will try and fail horribly.

 

[NL5]

Follow up question since this doesn't make sense to me:

I have two Zoeller pumps:
They are both at 5 feet head.
Model 57 which is rated at about 160 gallons per minute, 1/3 HP, 9.7 amps
Model 98 which is about 300 gallons per minute, 1/2 HP, 9.4 amps

Why would the less powerful unit draw more power?

Less efficient motor on the smaller pump.

 

[NAC]

Thanks everyone. I hope the power stays on for this storm

I forsee a more powerful generator in my future...

 

[edro]

Motor amperages are usually overstated on nameplates.
They are usually listed using values from UL tables, which are very conservative.

It might work just fine. You won't hurt anything.