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Discussion Starter #1
Hi all -

Building a house here and re-did the electrical service as the 3500sf house by default came with 200 amp service and 1 panel box. I asked for and am having 400-amp service with 2 200-amp (Panels A & B) installed as we have a lot of electronics equipment and want room to grow if we put a hot tub in, etc.

I've provided the electricians with lighting and electrical circuit and switch schedules and they are asking me for panel schedules.

I have:

28 interior electrical receptacle circuits
5 exterior electrical receptacle circuits
14 interior "dedicated" circuits for things like microwave, fridge, garbage disposal, washer, etc.
5 "high-draw" circuits for water heater, A/C condenser, range, dryer and furnace
14 lighting circuits

I've calculated lighting load schedules easily based on fixture wattage, etc. but have questions when it comes to receptacle loads, etc. and then panel design:

1.) Are there any best practices/code estimators for rating receptacle load circuit - ie. I have a circuit with 4 duplex outlets or a circuit with 3 duplex outlets and 1 quad outlet or a circuit with 4 duplex headed by a 1 GFCI outlet. How do I estimate wattage? Are there any differences if the circuit is a bedroom circuit vs. a bathroom vs. a kitchen circuit?

2.) How do you rate something like an A/C condenser - the one I am getting has these electrical specs:

Maximum Over-Current Protection Amps: 45
Minimum Circuit Ampacity: 28.2
Compressor Rated Load Amps: 21.15
Compressor Locked Rotor Amps: 96
Condenser Fan Motor HP: 1/4
Condenser Fan Full Load Amps: 1.7
Condenser Locked Rotor Amps: 3.1

How the heck do you figure out breaker size and wattage load? The Locked Rotor Amps is throwing me!

3.) How do I distribute these across 2 panels? Best to keep the high-draws and dedicated all on one panel and lighting/electrical on another? My goal is to a.) ensure no draws cause light flickering, b.) no electronics (computer equipment, AV, etc. gets damaged by surging power), c.) to have logical layout to follow to know where to throw circuit breakers for a room and d.) to have ample room to grow (which seems like I do with 71 out of 84 slots used - 13 free).

Thanks so much! I just want to have an educated draft to pass to the electrician!

Cheers!
Lee
 

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3.) How do I distribute these across 2 panels? Best to keep the high-draws and dedicated all on one panel and lighting/electrical on another? My goal is to a.) ensure no draws cause light flickering, b.) no electronics (computer equipment, AV, etc. gets damaged by surging power), c.) to have logical layout to follow to know where to throw circuit breakers for a room and d.) to have ample room to grow (which seems like I do with 71 out of 84 slots used - 13 free).
You can do all this if you like, but none of it make any sense.

Nothing will prevent the power from dipping when large loads start up. Even putting them in separate panels. Where do you think the panels are fed from? It's not like there is a one-way valve in the system preventing one panel from dipping. They both come from the same source. :whistling2:
Same exact thing goes for surges.
And IMO laying out breaker's positions according to location in the house is anal beyond comprehension. :icon_rolleyes:
 
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The general usage circuit loads on residential panels are too transient to predict what the loads will be.

Your AC needs a 30 amp circuit.
 
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Discussion Starter #6
LOL - I am a bit anal retentive though it does seem that logical ways are:

Lighting 1
Lighting 2
Lighting 3
Receptacle 1
Receptacle 2
Receptacle 3

or

Lighting 1 Lighting 2
Lighting 3 Receptacle 1
Receptacle 2 Receptacle 2

So I'm guessing none of that matters - nor does a recommendation of:

Lighting 1 - Living Room Receptacle 1 - Living Room
Receptacle 2 - Living Room Lighting 2 - Family Room
Receptacle 3 - Family Room


As for start-up flicker, understand it all comes from the same meter/feed.

My concern that prompted all this custom work was that there were like 4 lighting circuits and they were all at/near 80% max scheduled load for a 15-amp circuit - and that was before we added lights and determined bulbs we would use!

Thanks for responding - and I welcome everyone else's comments!

Cheers!
Lee
 

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Personally, Jim, I would recommend #10 wire on a 40 amp.
I meant 30 amp circuit ampacity, but was not clear. You and I knew what I was saying.
 
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