When terminating homeruns in a breaker panel, do you install all your higher rated breakers at the uppermost, or lowermost positions.

Why?

Our panels come preloaded with breakers bolted in position as per the panel schedules on the engineered prints. Kinda nice that way.

Yep, not always, but usually:

MAIN
1)RANGE 2)FURNACE
3)RANGE 4)FURNACE
5)WATER HEATER 6)DRYER
7)WATER HEATER 8)DRYER
9)KITCHEN 1 10)WASHER/LAUNDRY
11)KITCHEN 2 12)BATH 1
13)MICROWAVE 14)BATH 2
15)DISHWASHER 16)BATH 3
17)Bedroom AFCI 18)LIGHTS
19)Bedroom AFCI 20)LIGHTS
21)RECEPTACLES 22)RECEPTACLES
etc. etc.

Depending upon the loads and the job at hand...

I guess I want the Main bus to handle the least amount of current as possible. Putting higher loaded breakers near the top makes less of the bus heat up... That and I try to keep the kitchen circuits and other like circuits together.

<diclaimer>JMHO and my own theory, which could be greatly flawed. </disclaimer>

(Edited to repair an incomplete sentence...)

[This message has been edited by sparky66wv (edited 07-23-2002).]

Most people here install new panels with the highest rated C/Bs next to the main and then in descending order of current rating.

There's no requirement to do it that way, and extra circuits usually just get added in any convenient space.

I am wondering if this is really an issue. The bus is usually rated to handle the load and then some unless it is an unusual installation. I myself try not to put heavy loads back to back. Most panels are rated for maximum load per stab now and I am surprised at what the ratings are. Usually pretty high.

Lighting c/b's at the top.
I always put the heaviest loads as close as I can to the incoming power (why stress the buss?)
BTW, I normally deal with panels that aren't resi setups.
They'll always start looking at the top. That gives them some lights to find the problem.

Concentrating highest load circuits at the top would seem to do two things...places the largest heat generators together, and since heat rises, puts them in a naturally warmer location in the panel. Any other reasons for doing this?? Bad experiences distributing them along the buses??

66,

I like your panel arrangement.

When I apprenticed, seems like the majority of the panels I made up were "split-bus". The goal there was to get all the big loads on their own breakers, that counted as service disconnects, and to get the big loads off the "lighting main".

As I got further in my engineering studies, I continued to put the large loads close to the line terminations to help minimize the I²R heat generated in the panel.

The shorter the distance the large current travels inside the box, the less heat will be created by the resistance of the path.

Al

Monday I pulled a 50 amp double pole for a an AC condensor of off 40/42 in a 30 year old GTE panel, the busses looked like cast aluminum, the breaker was really hot and you could hear it arcing on the buss. I had 50 amp from the range as they were going to gas, and it was on 36/38. I pop it out and went to 5/7 and relanded the AC there,
water heater 1/3 sub feed for garage 2/4
AC condensor 5/7 dryer 6/8
fridgerator 9 washer 10
dishwasher 11 kitchen recepts 12
kitchen recept13 kitchen recepts 14
general lite 15 general lites 16
bath one 17 bath two 18
bath three 19 bedroom one 20
bedroom two 21 bedroom three 22
living room 23 storage room 24
sunroom 25 outside lites 26

I don't think that heat or electric stress is important.

I arrange them by use.

My main panel has a group of breakers for subpanels, a group for the HVAC, a group for large appliances, a group for the exterior, and a group for the garage the main is located in. There are empty spaces between the groups.

There are subpanels for my detached shop, the west bedrooms and baths, the living and kitchen, and the east bedrooms and baths.

Although largest next to main is the norm here, I don't believe it really makes that much difference. The busbar(s) should be sized to carry the maximum rated load of the panel with minimal voltage drop, even if the entire load is at the far end.

Sounds as though this might be another set of experiments for the ECN bench-testing group!

My 2 cents;

Heavy loads at top, try to separate at least 1 space between other frames.
LCL loads with >40% circuit rating go next.

Sensitive and light loads near the bottom.

Goal Electrically is trying to keep the surges and stuff from flowing through the entire bus, along with having heavy loads closer to the subfeed terminations.

Goal Thermally is to put the heat generating frames where the heat can dissipate better and not transfer to other frames via conduction [hence the attempt to leave a space between frames or sections of frames, along with staggering them back to back].

Does this makes sense???

Scott S.E.T.

Yet when you look at a SqD Homeline panel, if you look closely at the breaker assignment numbers. They imply that the double breakers go at the bottom. My experience has always seen them at the top with the same reasons listed here given.

I'm gonna dig deeper into this one.

Currently,
Are you sure you don't mean the "minis" go on the bottom.
This is where the panels that accept minis usually want tehm installed, as indicated by the bus diagram.
Although I have seen older panels that seemed to allow them in an irregular order.