Generator Wattage Start and Run.

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TC6969
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Joined: Wed Jul 18, 2018 2:40 pm
Location: Cocoa

Generator Wattage Start and Run.

Post by TC6969 »

The other thread got me wondering about this.

Lets pick two random wattages.

Lets say 2400 start/2000 run.

You start it up and plug in a refrigerator that take 1200 to start and 1000 to run.

After it starts, do you have 1000 watts in the bank to work with?

If so, then what happens to the starting wattage?

Next you plug in a room A/C unit that takes 800 start and 600 to run.

Do you now have 400 watts to play with?

Again, what happens to the starting wattage?

Or does the starting wattage go down in proportion to the load on the running wattage?

Inquiring minds want to know!
milsurp
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Location: Pinellas

Post by milsurp »

● The rated wattage corresponds to the maximum wattage the generator can output on a
continuous basis.
● The surge wattage corresponds to the maximum amount of power the generator can output for
a short period of time. Many electrical devices such as refrigerators require short bursts of extra
power, in addition the rated wattage listed by the device, to stop and start their motors. The
surge wattage ability of the generator covers this extra power requirement.

You are correct in your math on running wattage. The 400 watts are always there to start a device but you can damage the generator if you try to run the 2400 watts all the time.
cvo
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Location: Odessa

Post by cvo »

I seriously doubt a refrigerator will needs 1000 watts to run. Go to HF and buy a inline watt meter.
zeebaron
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Post by zeebaron »

cvo wrote: Mon Aug 03, 2020 9:25 pm I seriously doubt a refrigerator will needs 1000 watts to run. Go to HF and buy a inline watt meter.
When mine is on automatic defrost, I think it's about 700 watts. Running, it's about 180.
TC6969
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Joined: Wed Jul 18, 2018 2:40 pm
Location: Cocoa

Post by TC6969 »

cvo wrote: Mon Aug 03, 2020 9:25 pm I seriously doubt a refrigerator will needs 1000 watts to run. Go to HF and buy a inline watt meter.
This is just an example.

I pulled the figures out of my head just to have some numbers to work with.

I'm not suggesting that anything needs anything. :roll:
cvo
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Location: Odessa

Post by cvo »

zeebaron wrote: Tue Aug 04, 2020 12:41 am
cvo wrote: Mon Aug 03, 2020 9:25 pm I seriously doubt a refrigerator will needs 1000 watts to run. Go to HF and buy a inline watt meter.
When mine is on automatic defrost, I think it's about 700 watts. Running, it's about 180.

If it does draw 700 watts its a resistive load, not a inductive load like the compressor.
Rchrd.miranda
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Joined: Thu Jul 19, 2018 3:15 pm

Post by Rchrd.miranda »

A general rule of thumb.....Plug in the items with the greatest starting wattage first. Then plug in the next greedy device. You need to have enough power available to start #2 or #3 without going over the max surge watts. At some point you will find there isn't enough available power to start another device that requires starting surge amperage but you can add steady use items such as lights, T.V. etc up to the max capacity of the run mode. Most manufactures recommend the generator be operated at slightly less than the maximum rated run capacity (about 80%). The catch is that if you are running at max and that big item goes off and then restarts do you have enough surge capacity to get it back on line?

UNPLUG ALL POWER BEFORE SHUTTING GENERATOR DOWN. It isn't a great idea to let a generator just run out of gas when operating under load. The rapidly diminishing output may damage devices or the generator.

Just 2 cents from a country boy......Richard
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