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Is A 100 AMP Service Enough For Today's World

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#41 ·
Inner10 said:
Yeah but those are eastern standard amps not metric amps.
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Oh don't you worry. I used an Eastern Breaker.


Hope they don't change over to metric amps anytime soon. :sad:
 
#43 ·
I can remember years ago working in an 30 family apt building and having the new owner check the 60 amp panels. The building super put nickels under the fuses because the fuses were blowing all of the time, owner went crazy.

House I just finished working on has 3 br's, 400amp service with a backup generator that runs everything. Automatically starts every week for 1 hour.
 
#45 ·
Golden view said:
So if the generator runs everything, is it 96kw, or is the panel oversized?
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Not sure what size gen is, panels (3) not sure about being oversized. Generator is huge.
Electric appliances, 4 furnaces, 120 or so recessed lights, 3 fridges 2 freezers, lots of outdoor lighting, fountain etc.
Gen switch panel is 4' square, not sure why it runs every week though.
 
#48 ·
rrk said:
Not sure what size gen is, panels (3) not sure about being oversized. Generator is huge.
Electric appliances, 4 furnaces, 120 or so recessed lights, 3 fridges 2 freezers, lots of outdoor lighting, fountain etc.
Gen switch panel is 4' square, not sure why it runs every week though.
Click to expand...
Probably test run to ensure it will start.
 
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#49 ·
As said by others a load calc is the best solution. One must also remember that a 100amp service is not the max amp the service can use. One must also remember you do not count how many breakers/fuses there are and add up each breaker/fuse load for the load calc. Otherwise if that were true some folks would need a 1000amp service or bigger. Go through the home and make a list of how many lights at what wattage, list of TV's, appliances, heat sources, water pump? Hot water tank? TV Dish or cable box? Possibility of kids games? Computers? Vacuum?
 
#50 ·
100 amps X 240 volts = 24 kw

24 kw x 8 hours + 10 KW x 16 hours x 30 days = 10560 kwh x 16 cents/kwh =

$1690 a month electric bill if a 100 service was loaded only 8 hours a day.

Anybody pay this kind of bill? If not than 100 amps is more than adequate.
 
#51 ·
Fault Current said:
100 amps X 240 volts = 24 kw

24 kw x 8 hours + 10 KW x 16 hours x 30 days = 10560 kwh x 16 cents/kwh =

$1690 a month electric bill if a 100 service was loaded only 8 hours a day.

Anybody pay this kind of bill? If not than 100 amps is more than adequate.
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I was going to do this math and post but I was too lazy. Thanks.
 
#54 ·
The service is based on highest peak load, not continuous draw. So when someone turns on the range and all the oven burners, the MW has the electric dryer and washer going and decides to dry there hair while using an electric heater in the room the main won't blow. Well, until the electric water heater switches on :blink:
 
#55 ·
Load

Actually, a residential service is rated per NEC load calculations including demand factors, not peak load.

The demand factor of 35% or 40%, depending on which method, is based on the probability of loads operating at the same time - coincident.

3 watts a square foot for general lighting, 1500 kva for small appliances and laundry, and so forth.

The question was is a 100 amp service too small? How many people have seen a tripped 100 amp caused by excessive load?
 
#56 ·
Fault.... Welcome aboard :thumbsup:

While you are over here, wonder if I can pose a question that was previously unanswered on the thread that had the AF tripping but only when all three lights were under load.

(I'm a GC, can wire a common residential with help/attention to NEC changes, but I'm clearly NO pro sparky and with only very basic understanding.)

But with regard to arc faults, which I guess is simply/basically current jumping through the air, ..... is the likelyhood of an arc fault situation sensative to (a function of) voltage or current.... or maybe both, or maybe primarily voltage or primarily current. (My reference would be in the neutral where current was limited/defined).

This is basically just curiosity and seeking more understanding.

TIA

Best

Peter
 
#57 · (Edited)
Arc fault

The cause of many electrical fires in homes (and Apartments, etc) was determined to be the failure of the standard circuit breaker to detect common occurrences like a bad connection at a receptacle, frayed cords, loose wire nuts, broken appliances, and similar problems. The technology available today is capable of responding to these problems and hopefully, prevent fires.

The whole idea of AFCI was to sense "low level arcing faults" that will not trip a standard circuit breaker but will burn your house down. We have all seen and heard the arcing when a frayed cord shorts out. You can see the arc, a puff of smoke, and hear the "bacon frying" sizzling sound. The nature of this high frequency arcing current is what the AFCI is designed to detect.

Unfortunately the earliest designs would also trip when motor brushes arced, dimmers were poorly designed, switching power supplies of lights and appliances were poorly designed, and so forth. Gave the AFCI a bad rap, and deservedly so.

Newer designs are supposed to be more sophisticated and less prone to false tripping.

In the case of LED fixtures and incandescents being on the same circuit and tripping the AFCI, I doubt the incandescents are the problem. Could be wiring problem like a bad splice, wire broken under the insulation, bad switch or dimmer. I suspect the LED's could be the culprit. Try removing the LED fixtures from the circuit and see what happens.

And Elvis has left the building.....
 
#58 ·
MTN REMODEL LLC said:
But with regard to arc faults, which I guess is simply/basically current jumping through the air, ..... is the likelyhood of an arc fault situation sensative to (a function of) voltage or current.... or maybe both, or maybe primarily voltage or primarily current.
Click to expand...
I understand that sentence about as well as you understand arc faults. :blink: :laughing:

The closest answer is going to be "both". Without voltage, you will have no current flow. Without enough voltage to force current across an air gap, there will be no arc.

It takes only a relatively small amount of voltage to force an arc across a gap of 0.001", but it takes thousands of volts to force an arc over a gap of 1".

In either case, such an arc produces radio-frequency energy, which is what arc fault breakers look for. They analyze the intensity and frequency pattern of the signal to determine whether it's most likely a dangerous condition or just "background" noise caused by something like motor brushes.

Uh... what was the question?
 
#59 · (Edited)
Tinstaafl said:
I understand that sentence about as well as you understand arc faults. :blink: :laughing:

The closest answer is going to be "both". Without voltage, you will have no current flow. Without enough voltage to force current across an air gap, there will be no arc.

It takes only a relatively small amount of voltage to force an arc across a gap of 0.001", but it takes thousands of volts to force an arc over a gap of 1".

In either case, such an arc produces radio-frequency energy, which is what arc fault breakers look for. They analyze the intensity and frequency pattern of the signal to determine whether it's most likely a dangerous condition or just "background" noise caused by something like motor brushes.

Uh... what was the question?
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Thanks for the response...Sorry it was confusing to you.... I'll try it again....

Let's pretend a 120 volt circut with a 6 amp heater on it, with the neutral broken, (and connsequently a potential load on the neutral), but the break in the neutral is in just close enough proximity to itself to almost cause an arc fault....

1) Would increasing voltage in the circut eventually cause an arc fault (I intuitively think so and believe you allreeady answered yes in the above)

Yes or No

2) Without increasing voltage, but now we increase potential current by plugging in more heaters (increasing possible amperage/current), would we eventually get an arc fault. (I think no... but am not sure)

Yes or No



(It's just mostly a curiosity question Tin... but it goes to the issue of the other thread when the AF seemed only to trip when there was a greater current/amperage draw. )

TIA
 
#60 ·
First off, forget about focusing on the neutral conductor, that's a red herring. You are just as likely to have arc faults on the hot.

An open neutral is just a bit more difficult to recognize, because you are expecting to see zero volts with reference to ground, and you often will whether it's open or not.

MTN REMODEL LLC said:
1) Would increasing voltage in the circut eventually cause an arc fault (I intuitively think so and believe you allreeady answered yes in the above)
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Yes, but in theory the circuit voltage will never vary more than a couple percent--generally not enough to make much difference. Unlikely.

2) Without increasing voltage, but now we increase potential current by plugging in more heaters (increasing possible amperage/current), would we eventually get an arc fault. (I think no... but am not sure)
Click to expand...
In your scenario, nothing would happen because you have an open neutral and therefore NO current would flow.

Now if instead, you have an "iffy" connection on either the hot or the neutral, it's going to be somewhat resistive. Current flowing through a resistance develops heat. More current = more heat. When you heat things up, they move. There's where higher current can lead to arcing.

Unless the aforesaid movement happens to result in a better connection.
 
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