Lights Getting Brighter - Possible Loose Neutral? MBroad

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MBroad

Joined May 16, 2016
9
Ok, I have talked to the neighbors around me, they all day theirs do the sad be thing. So I guess I'll be calling the power company on Monday.
As a side note, just for my knowledge. If the house has a 100 amp main breaker but the sum of all the other breakers add up to 280 amps, how does that make any since? I'm just a little curious. I try to stay away from electrical power. Kinda tingly when you hit 110v but 220v hurts a bit.
 

WBahn

Joined Mar 31, 2012
27,868
Ok, I have talked to the neighbors around me, they all day theirs do the sad be thing. So I guess I'll be calling the power company on Monday.
As a side note, just for my knowledge. If the house has a 100 amp main breaker but the sum of all the other breakers add up to 280 amps, how does that make any since? I'm just a little curious. I try to stay away from electrical power. Kinda tingly when you hit 110v but 220v hurts a bit.
"they all day theirs do the sad be thing" ... huh???

Each individual circuit can handle a certain amount and that circuit's breaker reflects that amount, but not all of the circuits are in use, at their max limit, at the same time. The total of ALL the circuits combined can't exceed 100 A at any given time, spread out among all of the breakers, each of which can't exceed it's own particular rating.
 

#12

Joined Nov 30, 2010
18,224
If the house has a 100 amp main breaker but the sum of all the other breakers add up to 280 amps, how does that make any since?
First, you never use up all the power available from any one breaker. Second, you never have everything in the house turned on at the same time.

Now the other side of the coin: You might have the central furnace running at 10KW and the water heater running at 3500 watts and the clothes dryer running at 5Kw and the kitchen stove on at 3Kw and you're at 89.5 amps. Throw in a refrigerator at 3 amps and a microwave oven at 10 amps and you're at 102.5 amps. POP go the main breakers. An old 60 amp house doesn't stand a chance.

You never exceeded the ability of any one breaker, but they all added up to over 100 amps. That's why houses today get 150 amps or 200 amps for their mains.
 

wayneh

Joined Sep 9, 2010
17,189
There's a whole science in predicting the "usage factor", or whatever the term is, the percentage of capacity that a particular usage will typically use. For instance a fast food restaurant might use, on average, 60% of their rated maximum. Their needs are fairly consistent and predictable. A residence might average only 30%. A home requires more headroom because the usage is sporadic and unpredictable as #12 has laid out.

If you're the power company and your job is to supply all these various kinds of customers with reliable power, you find yourself in the statistical modeling and prediction business.
 
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