Circuit Loads
 

When planning circuits, what do you allow for outlets when figuring
the total load? I have a 15A circuit with very little on it, but 8
outlets. Is there a standard amp draw assumed for outlets?

Yes, for general lighting outlets 1.5 amps per outlet or max 10 outlets on a
15 amp circuit
"TrueWest" wrote in message
...
When planning circuits, what do you allow for outlets when figuring
the total load? I have a 15A circuit with very little on it, but 8
outlets. Is there a standard amp draw assumed for outlets?

It really depends on where you live (Canada/US) and if this is a home or
commercial. There are no rules on general lighting outlets per circuit, only
the load per square foot of space covered (3va/ft2) if this is US residential.
You do have "design" concerns to serve the load you plan on using.

From: TrueWest


When planning circuits, what do you allow for outlets when figuring
the total load? I have a 15A circuit with very little on it, but 8
outlets. Is there a standard amp draw assumed for outlets?

No. The number of outlets on a residential convenience circuit is unlimited.

The number of circuits is calculated at 3 watts per sq. ft. The (minimum)
number of outlets is determined by linear wall space.

So if you end up with 5 circuits and 50 outlets, plan on 10 outlets per
circuit. If you end up with 60 outlets, figure 12 per circuit.

And it's perfectly legal to shift the number of outlets to ease the job or
facilite better distribution based on known usages - like put 14 on one, but
only 6 on another.

Yes. In Canada, the max residential is 12 outlets per circuit, max predicted
12 amps on a 15 amp circuit, and we assume about 1 amp per average duplex
receptacle. A bathroom where you might use a hairdryer or other high
consumption device would require more latitude.

Dave

"Greg" wrote in message
...
It really depends on where you live (Canada/US) and if this is a home or
commercial. There are no rules on general lighting outlets per circuit,
only
the load per square foot of space covered (3va/ft2) if this is US
residential.
You do have "design" concerns to serve the load you plan on using.

A bathroom where you might use a hairdryer or other high
consumption device would require more latitude.

Bathrooms, kitchens and laundries require 20a dedicated circuits (2) in
kitchen.
The original question was about the general lighting circuits. In the US these
are distributed equally based on the VA per square foot (3va) and the
receptacles are placed based on the average length of a lamp cord (6 feet). The
objective is not to have any wall space 2' or longer, not more than 6 feet from
a receptacle and that no cord will have to be pulled across a door opening or
other hazard.
There is no limit on how many receptacles that is since they assume you will
not really use them all anyway. It is purely based on the projected load of 3va
per square foot.
This is just the minimum. You can always put in more.
We plug in a lot more things than our parents but generally they use less
power. Large loads are usually put on dedicated circuits.

"Greg" wrote in message
...
A bathroom where you might use a hairdryer or other high
consumption device would require more latitude.

Bathrooms, kitchens and laundries require 20a dedicated circuits (2) in
kitchen.
The original question was about the general lighting circuits. In the US
these
are distributed equally based on the VA per square foot (3va) and the
receptacles are placed based on the average length of a lamp cord (6
feet). The
objective is not to have any wall space 2' or longer, not more than 6 feet
from
a receptacle and that no cord will have to be pulled across a door opening
or
other hazard.
There is no limit on how many receptacles that is since they assume you
will
not really use them all anyway. It is purely based on the projected load
of 3va
per square foot.
This is just the minimum. You can always put in more.
We plug in a lot more things than our parents but generally they use less
power. Large loads are usually put on dedicated circuits.


I have heard about those 20 amp circuits, but they are rarely used in
Canada (too bad). Here, for a kitchen the duplex receptacles are usually
wired with 15 amp circuits, but the upper and lower plug of the receptacle
must be on separate circuits. For a bathroom, 15 amp GFI-protected plugs are
the norm. Almost all home wiring is done with 14 gauge romex, not the 12
gauge wire that you more commonly use in the US. I like the increased
versatility you have, unfettered by the worry about exceeding a maximum
fixture count during the planning stage. On the other hand, if you later
discover that a circuit is overloaded and breakers are tripping, you then
have some remodeling to do.

You make a good point about the trend toward increasing use with each
generation. Whether that trend will continue is hard to say.

Dave

You make a good point about the trend toward increasing use with each
generation. Whether that trend will continue is hard to say.

We plug in a lot more stuff but it is generally lower wattage than our parents.
A new TV is really more like a big lamp. You could cook a chicken in one of
those old tube sets.
Central heating and A/C has taken the place of space heaters and window shaker
A/C units. People are finally starting to discover compact flourecent bulbs.

According to Dave :
I have heard about those 20 amp circuits, but they are rarely used in
Canada (too bad).

Recent code changes in Canada are going to make them a lot more common - at
least in kitchens.

Up until recently, kitchen counter outlets could _only_ be split duplex 15A
dual circuits. New GFCI requirements for kitchen counter outlets (very
much like the US') mean that you either have to use dual GFCI breakers for
them (very pricey), or, use US-style 15A/20A 12ga circuits with a GFCI
outlet (just like the Americans have for a while).
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.