Household Amperage: Typical Usage & Power

  • Thread starter Thread starter Philosophaie
  • Start date Start date
  • Tags Tags
    Amperage
AI Thread Summary
Typical household amperage in the U.S. ranges from 150 to 200 amps, depending on the size and electrical load of the home. Most residential systems operate at a supply voltage of 240V, with 120V available for standard outlets. Industrial amperage requirements vary significantly, with some systems requiring thousands of amps at high voltages. The discussion also highlights the confusion around voltage standards, noting that while 120V is commonly referenced, actual voltages can fluctuate. Overall, understanding household and industrial amperage is crucial for ensuring adequate electrical supply and safety.
Philosophaie
Messages
456
Reaction score
0
What is the typical Amperage that comes into a normal household?
 
Engineering news on Phys.org
Philosophaie said:
What is the typical Amperage that comes into a normal household?

Less than the service breaker rating. Most residential homes have around a 150-amp to 200-amp service. The load will depend on what is on in the house of course.

CS
 
Well it depends upon the supply voltage.

What is yours?
 
Studiot said:
Well it depends upon the supply voltage.
True, but AFAIK, most countries use similar supply voltages in the 220-240V range. The US uses 240V and typical amperages range from 40A for a small apartment to 200A for a medium-sized house.
 
How many amps tipically for an Industrial 3-phase Y and Delta?
 
Typical Amperage for 3-phase.
Supply to Demand:

Delta to Delta
Deltas to Y
Y to Delta
Y to Y
 
Philosophaie said:
How many amps tipically for an Industrial 3-phase Y and Delta?
There is no "typical" for industry since industrial requirements can vary by several orders of magnitude. You could see anything up to a few thousand amps at anything up to 13,200 volts. From a few kilowatts to a few dozen megawatts.
 
russ_watters said:
There is no "typical" for industry since industrial requirements can vary by several orders of magnitude. You could see anything up to a few thousand amps at anything up to 13,200 volts. From a few kilowatts to a few dozen megawatts.
You got me curious as I was thinking about http://en.wikipedia.org/wiki/Electric_arc_furnace" .
A mid-sized modern steelmaking furnace would have a transformer rated about 60,000,000 volt-amperes (60 MVA), with a secondary voltage between 400 and 900 volts and a secondary current in excess of 44,000 amperes.
 
Last edited by a moderator:
russ_watters said:
True, but AFAIK, most countries use similar supply voltages in the 220-240V range. The US uses 240V

Strange, I always thought it is 110/120V. That's why we here have problems with things bought in US.
 
  • #10
The US feeds street-level transformers with high line voltages, and the transformers knock the voltage down to 240V. The secondary coils are center-tapped to provide 120V to each of the two legs at the breaker panel. We only get 240V when loads are connected leg-to-leg, like electric ranges, clothes dryers, and submersible pumps.
 
  • #11
Yes 120volts would be nominal. But...
In the United States[3] and Canada[4], national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 to 126 V (-5% to +5%). Historically 110, 115 and 117 volts have been used at different times and places in North America. Main power is sometimes spoken of as 110; however, 120 is the nominal voltage.
http://en.wikipedia.org/wiki/Mains_electricity#Standardization"
 
Last edited by a moderator:
  • #12
In my first house (back in the 1970s) i had a problem with lights burning out very quickly. When I checked the line voltage it was 127.x VAC. When I switched to sylvania bulbs from the GE I was using they lasted almost twice as long... all I can think is that GE specs their lights at 110 and Sylvania specs them at a higher voltage.
It all depends on where you are on the grid as to what your actual voltage is.
 
  • #13
Borek said:
Strange, I always thought it is 110/120V. That's why we here have problems with things bought in US.
turbo-1 said:
The US feeds street-level transformers with high line voltages, and the transformers knock the voltage down to 240V. The secondary coils are center-tapped to provide 120V to each of the two legs at the breaker panel. We only get 240V when loads are connected leg-to-leg, like electric ranges, clothes dryers, and submersible pumps.
So that's 120V (or in special cases 240V) at the wall, but 240V at the main electrical panel. It's nice for flexibility.
 
  • #14
russ_watters said:
So that's 120V (or in special cases 240V) at the wall, but 240V at the main electrical panel. It's nice for flexibility.
And generally topped out at 200 amps design rating at the main panel and breaker box. In the US, we generally have 15 amp breakers, and in bridged (240 V) breakers the total amperage is 30 amps.
 
  • #15
turbo-1 said:
And generally topped out at 200 amps design rating at the main panel and breaker box. In the US, we generally have 15 amp breakers, and in bridged (240 V) breakers the total amperage is 30 amps.

Care to explain that?
 
  • #16
I think he's talking about a two-pole (so 240V) breaker being 15+15=30A. If so, it isn't correct. 15A times two poles is still just 15A. Nor is the typical amperage correct. 40A breakers are pretty standard for large household devices and you'll occasionally see 60A breakers.
 
  • #17
Looking at both the OP's questions together I wonder if this is homework?
 
Back
Top