# Balanced Load??



## Chuck (Feb 11, 2014)

What is meant by a balanced load? How important should it be to me?


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## aandpdan (Oct 8, 2012)

It can be very important.

If your generator has 240 volt outputs then there are two "hot" legs from the generator.

From leg 1 to neutral is 120 volts.
From leg 2 to neutral is 120 volts.
From leg 1 to leg 2 is 240 volts. 

240 volt loads are balanced as they use both legs.

Balancing your load refers to 120 volt loads. Your generator may be rated at 5000 watts but you can't pull 5000 watts off of one leg. You can only pull 2500 watts off of each. 

Ideally you will have both legs balanced as close as possible. For example:

Refrigerator - 750 watts.
Boiler and pump - 700 watts.
TV and internet - 150 watts.
Lighting - 100 watts.

You'd put the refrigerator and lighting on one leg - 850 watts.
You'd put the boiler and TV on the other - 850 watts.

Some variation is normal. You'll never get them perfectly balanced as loads vary.


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## Chuck (Feb 11, 2014)

Thanks aandpdan.
Does a leg refer to a receptacle? And what can go wrong with an unbalanced load?


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## aandpdan (Oct 8, 2012)

Not a receptacle.

In the US we use a 120/240 volt system - 3 wires. HOT/Neutral/HOT

Each hot is a "leg." In the diagram below the +++++ is a winding in your generator, the ----- is just the lead to it.

Leg 1 ----- +++++ ------ NEUTRAL ----- +++++ ----- LEG 2.

/\ ---------120 V -----------/\-----------120 V ----------/\

/\ -------------------------240 V-------------------------/\

In effect, a generator is a center tap transformer. The polarity between the two legs at any moment in time is 180 degrees apart (opposite).

HOT to neutral is 120 volt, HOT to HOT is 240 volt. 

Back to the example of a 5000 watt generator, it's really 2500 watts per leg. If you put all the loads on one leg, you could burn out the winding on the generator.


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## whimsey (Dec 13, 2013)

Interestingly enough I noticed that in my B&S 5500 watt generator they says to balance out the load on the 120 V circuits use the top upper left plug first and the second load into the plug below it and the third plug into the top right plug and the fourth into the bottom right plug. I mistakenly assumed that like a socket in the house that both the plugs of each socket were on the same circuit. It doesn't look that way. The top plug of the left and right side socket are connected and the same for the bottom of the left and right socket. 

Whimsey


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## aandpdan (Oct 8, 2012)

Good observation.

Most generators split outlets. The top of a standard receptacle would be on one leg and the bottom on the other. 

It's a multi-wire branch circuit, commonly used in homes.


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## Chuck (Feb 11, 2014)

So I shouldn't run my gens with only a 600w quartz light plugged in?

Also, should a gen always be grounded when ran? If so, for what reason?


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## aandpdan (Oct 8, 2012)

You can safely run only a 600 watt light. It really only become a problem as you get heavier loads on the generator. Just remember what your limit is per winding - 1/2 the total output.

If you connect to a transfer switch your generator is grounded, via the house grounding electrode system. 

Fault current from a short won't go into the earth, it would use the equipment grounding conductor and return to the generator. IMHO it won't do anything, but, just follow your manufacturers recommendations. In your residence it is primarily for lightning protection.


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## Chuck (Feb 11, 2014)

Ok. Thanks, aandpdan.


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