ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Do You Travel?
by gfretwell - 05/10/21 06:47 PM
Any Woodworkers here?
by gfretwell - 05/10/21 06:26 PM
Your favourite food?
by gfretwell - 05/10/21 06:13 PM
Lock-down Thread
by gfretwell - 05/10/21 06:12 PM
Just be aware of this...
by Trumpy - 05/10/21 06:47 AM
New in the Gallery:
2020 - 2021 Winter Project
Garden 2021
Who's Online Now
1 registered members (gfretwell), 18 guests, and 20 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Split Bus Breaker Panel #221146 01/25/21 01:35 AM
Joined: Jul 2004
Posts: 9,610
gfretwell Online Content OP
This is the unicorn. First one I have ever seen. I am still not sure why this was a thing.
Has anyone seen one of these?

[Linked Image from]

[Linked Image from]

Greg Fretwell
Work Gear for Electricians and the Trades
Re: Split Bus Breaker Panel [Re: gfretwell] #221150 01/27/21 04:29 PM
Joined: Apr 2002
Posts: 7,254
HotLine1 Offline

Yes, I have come upon split bus panels over the years. main reason for using these is ....there is no 'main' CB; via the six-switch rule. The top section is 'supposed' to be ONLY 5-2 pole breakers (the 6th feeds the lower section)

Now, the above being 'the rule'; I came upon many that had more then 6 switches in the top section.

That's the only reason that I can come up with for this setup.

Re: Split Bus Breaker Panel [Re: HotLine1] #221152 01/27/21 05:57 PM
Joined: Aug 2011
Posts: 27
grich Offline
Originally Posted by HotLine1

...I came upon many that had more then 6 switches in the top section...

So some of the 2-pole breakers were removed and 1-pole breakers loaded instead? Nice.

Probably tandems, too. smile

Re: Split Bus Breaker Panel [Re: gfretwell] #221153 01/28/21 02:00 AM
Joined: Jul 2004
Posts: 9,610
gfretwell Online Content OP
This particular panel has plenty of breaker slots below for your general lighting circuits. I just never saw a breaker panel with a spiit bus, I have seen plenty of split bus fuse panels. That was probably because fuses over 60a started getting pretty expensive.
This particular one really surprised me because of how small it was. You could put in a regular 150a load center with a main breaker and still have plenty of opportunity for up to 100a feeders using branch circuit rated breakers. Those service rated breakers have to be pretty expensive. I might understand this if it was a 400a panel and you were feeding a 200a feeder along with some other loads, still serving your general lighting from here. I did that with a 200 and a 150a feeder off of it at my house. I had the 8 slot 150a service rated breaker even tho a regular one would have worked.
It is all moot now. In the 2020 code that panel is illegal. (One service disconnect per enclosure, grouped, with up to 6 boxes instead of up to 6 in one box) 230.71

Greg Fretwell
Re: Split Bus Breaker Panel [Re: gfretwell] #221163 02/04/21 09:14 AM
Joined: Jun 2002
Posts: 42
WNYJim Offline
Seems hard to be believe when you look at how split-bus panels were made but the 100 Amp panel cost was less (I think it was $5, might have been $2) than a main breaker panel. The place I've seen this panel the most is in tract homes.

Re: Split Bus Breaker Panel [Re: gfretwell] #221164 02/07/21 09:29 PM
Joined: Mar 2004
Posts: 782
BigB Offline
I can't see the pics for some reason. Split bus
panels were very popular here as the main service, we have swapped out hundreds. Mostly FPE but some GEs as well and a few QO. One house had a QO with 3 busses, first one of those I ever saw on a residential service. Most of our service equipment is outdoors and FPE made a 200 amp split bus outdoor panel that found it's way onto thousands of tract homes here. Of course DIYs and AC guys don't understand them and just plug stuff on anywhere they see a hole.
edit: I figured out the pics, seen a few of those too but the FPE was by far the most popular. A lot of times home inspectors will call those out for not having a main and we have to explain the 6 main rule.

Last edited by BigB; 02/07/21 09:33 PM.
Re: Split Bus Breaker Panel [Re: BigB] #221165 02/08/21 08:37 PM
Joined: Oct 2000
Posts: 4,005
Bill Addiss Offline
I can't see the pics for some reason

It looks like Chrome and MS Edge are 'protecting us' from seeing the images in the post.

For anyone else that can't see them you can right click on them and have them open up in a new tab.

Re: Split Bus Breaker Panel [Re: gfretwell] #221183 02/15/21 01:21 PM
Joined: Feb 2010
Posts: 6
New Member
I've seen & replaced many, they were common in St.. Louis area. Mostly FPE, probably because we had an FPE manufacturer (closed around 1984 when Washington Univ wanted the property). They are still legal to stay, but most buyers inspectors call for replacement.

Re: Split Bus Breaker Panel [Re: gfretwell] #221185 02/15/21 03:30 PM
Joined: Jul 2004
Posts: 9,610
gfretwell Online Content OP
That is the FPE problem, not the split bus tho although I imagine a lot of HIs are confused by them. Most HIs are confused about a lot of electrical issues. I assume a plumber would have the same opinion about HI's plumbing knowledge. Most of them passed a trivial test, sent a check to HACHI or someone similar and "poof" you are a certified HI.

Greg Fretwell


2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Posts: 22
Joined: August 2009
Show All Member Profiles 
Top Posters(30 Days)
Trumpy 19
Admin 8
Popular Topics(Views)
278,812 Are you busy
211,974 Re: Forum
199,011 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3