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Generator - Surge Power Question

hhsieh's Avatar

Join Date: Dec 2005
Posts: 52

06-09-08, 07:25 AM   #1  
Generator - Surge Power Question

Hello there! I'm trying to purchase a generator for my home emergency use, a surge power rating question came up:

The generator I'm interested in (one that's very portable) has a rating label says:

Operating Power Output: 1500 W
Max Power Output: 1850W

When I ask about whether it'd work with a typical home refrigerator, the store attendant got the following benchmark data for me:

Operating Power (Fridge): 700 W
Surge Power (Fridge): 2500 W

I don't know exactly what that 2500 W was about. I assume it is the start-up power rating.

My questions:

1. Will this generator work with a typical 20-25 cu.ft home fridge?

2. If it'd work, would the underrating eventually bring down my (i) refrigerator, or (ii) generator over time?



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cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,571

06-09-08, 09:53 PM   #2  
I don't think you'll be able to run that fridge on that generator. The compressor in the fridge takes a bit of wattage when it comes on...just for a moment...but the generator you have in mind won't supply that requirement and might harm the fridge if you were to try to run it on that. You'll need to look for no less than a 3500 watt generator I think. You always want to have more capacity than demand.

"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

french277V's Avatar

Join Date: Mar 2006
Posts: 4,808

06-09-08, 11:53 PM   #3  
Most gas powered portable generators don't have much surge reserve capictay at all due they are pretty close to the limit of the generator design.

the reason why they limited on the surge capitcy due the size of generator and the primemover can able keep up with the load on the generator itself.

For most portable generators I typically see around here most will ask for min of 3500 watts or larger the quick point is motor starting reserve many electric motors will take up to 6 to 8 times of running amp for few seconds.

The typical motor useage are found in:

• Refridgeators [ pretty good percentage do have two motors in there { compressor and interal fan } the watteage will varies a bit depending on the size { useally 100 to 800 watts depending on design}

• Furance blower motor useally anywhere from 1/3 HP to HP motor on them

• Waterpump again.,, it will varies from 1/3 hp and up depending on set up.

• Luminaires for the indentscent [ filment type ] they are not really affected by generator load at all. but CFL some may work ok with generator power some don't.

But there is larger size and with larger units they can be portable but most useally are stationary set up typically those unit can handle pretty good load in nice way and they are typically 7.5 KW [ 7500 watts ] or larger.

Oh yeah .,, a good head up watch out with your computer some of them don't run on generator power very well at all [ some are very picky on it ]

{ little off topic but it is releated to this not too long ago I installed pretty big one a 100 KW [ 100,000 watts ] that will take care of everything in the house what ya think you can throw it on. }

My house/shop have two generators a 20 KW and 5 KW unit both are slow speed diesel units and i have so much room leftover before i hit the limit on my 20KW unit.


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