ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
Video: Inventor of the GFCI self-testing shocks
by Bill Addiss. 01/17/18 11:11 PM
FPE in Germany
by HotLine1. 01/17/18 07:07 PM
Fujifilm Recalls Power Adapter Wall Plugs
by Admin. 01/16/18 07:04 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 4 guests, and 13 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Running out of breaker space in new panels #208028
12/21/12 03:11 AM
12/21/12 03:11 AM
B
bossanova5  Offline OP
Member
Joined: Oct 2012
Posts: 13
L.A. CA
Hello all,

I'm upgrading a building for a machine shop with three new 225 amp 208/120 volt three phase 42 space panels.

I have over 50 machines to wire up and I'm running out of breaker space in the panels.In one section I have 29
machines that pull 16 amps under full load.I plan on putting them on 20 amp three pole breakers(They are being fed with #12 wire currently with a 30 amp fused disconnect(Allready exisiting on the machines)

I want every machine to have it's own breaker

Since I can only get 14 breakers per panel I'm thinking about adding a secondary panel or extension panel that will feed off of the bus bars from the 225 amp panels to create more space(not a sub).The feeder panel will have a 225 amp mainbreaker in it.While the secondary will be just busbars.I plan on using 3/0 as the jumpers from the main panel to the secondary panel.

All of the machines are not going to be used at one time so there's really no chance of an overload.

I'm pretty sure this is legal.

Any and all advice is appreciated.

Thanks




Work Gear for Electricians and the Trades
Re: Running out of breaker space in new panels [Re: bossanova5] #208031
12/21/12 10:34 AM
12/21/12 10:34 AM
HotLine1  Offline

Member
Joined: Apr 2002
Posts: 6,918
Brick, NJ USA
What you need, and I hope you already have is a 'main panel' with feed thru lugs, you will be OK.

Based on your OP above, is that how you are going from panel to panel?



John
Re: Running out of breaker space in new panels [Re: bossanova5] #208042
12/21/12 03:17 PM
12/21/12 03:17 PM
B
bossanova5  Offline OP
Member
Joined: Oct 2012
Posts: 13
L.A. CA
I'm feeding two 225 amp panels through the exisiting 400 amp switchgear from one 225kva transformer that allready exsists.Each panel will have a 225amp main protecting it at the switchgear.

I'm adding another 225kva transformer and adding two more 225 amp panels directly tapped from the transformer which will have mains built in the panels.

Three of the panels will have feed through lugs that will feed the secondary panels.

Thanks for the input

Re: Running out of breaker space in new panels [Re: bossanova5] #208046
12/21/12 05:25 PM
12/21/12 05:25 PM
HotLine1  Offline

Member
Joined: Apr 2002
Posts: 6,918
Brick, NJ USA
Sounds like a plan!

BTW, Welcome to ECN!!


John
Re: Running out of breaker space in new panels [Re: bossanova5] #208052
12/22/12 04:20 AM
12/22/12 04:20 AM
B
bossanova5  Offline OP
Member
Joined: Oct 2012
Posts: 13
L.A. CA
Thanks John for your input

Re: Running out of breaker space in new panels [Re: bossanova5] #208054
12/22/12 08:33 AM
12/22/12 08:33 AM
T
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
With motor control the NEC has permitted panels beyond 42 spaces for the longest time.

You might get quotes going both ways -- since there's some labor economy to using fewer parts.

Sometimes space, itself, is a hassel.



Tesla
Re: Running out of breaker space in new panels [Re: bossanova5] #208059
12/22/12 01:51 PM
12/22/12 01:51 PM
B
bossanova5  Offline OP
Member
Joined: Oct 2012
Posts: 13
L.A. CA
Where exactly does it state in the code that it permits more than 42 spaces in a panel when dealing with motor controls?

Thanks

Re: Running out of breaker space in new panels [Re: bossanova5] #208062
12/22/12 03:29 PM
12/22/12 03:29 PM
G
gfretwell  Offline

Member
Joined: Jul 2004
Posts: 9,166
Estero,Fl,usa
The recent code has actually lifted all restrictions on breaker count (2008 I think)

I have not compared the pricing tho. Until they get into the supply chain in quantity, 2 panels may be cheaper of one is MLO.


Greg Fretwell
Re: Running out of breaker space in new panels [Re: bossanova5] #208071
12/22/12 11:14 PM
12/22/12 11:14 PM
T
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
Way, way back in the olden days...

There was a 42 circuit limit on LIGHTING PANELS. (Only)

In a footnote, it was mentioned that if there were no lighting (and appliance-- eg 1-phase recepticals and such) loads, the panel was not deemed a LIGHTING PANEL.

That little detail skipped by most of us commercial electricians because we almost never touched a panel that would not be deemed a LIGHTING panel.

If you dig out your ancient Square D catalogs -- and peruse their I Line offerings it will be quickly apparent that 54 circuit panels were an industrial option from... forever.

The ancient panels would often termed 'controlling' because the industrial firm would turn the big motor(s) on and off back at the panel.

This practice pre-dates modern notions of motor control.

In the beginning, even switches were expensive, and so reduced to the bare minimum.

This practice dates into the 19th Century. You can see such devices in museums, or old photos. It's hard to believe that knife switches were used to control high horsepower switches -- but they certainly did in the field of electric traction motors! (railroads)

BTW, the guys throwing those switches looked like Dr. Frankenstien -- of moviedom -- with his googles and massive insulating gloves, as he threw his 'monster' switch.

That practice is exactly where the movie crew got the whole idea.

=========

The actual wording never stated that it was permitted to exceed 42 spaces -- the wording was that LIGHTING panels were RESTRICTED to 42 spaces. It then went on to describe our common variety breaker panels as being just such restricted panels.

That restriction has been lifted because of the AFCI. It's now hopeless to construct a McMansion with only 42 spaces -- while meeting the code -- and using but one panel.

So, NEMA threw the limit away, and had the NEC agree.

BTW, there was a period when fuse boxes were restricted to just six fuses. Again, that limit was eliminated when it proved inconvenient. But, you will find simply no end of antique fuse boxes limited to just six.

With them, the residence could technically eliminate a MAINS cut-off. That's just how cheesy things were. (Think retrofit shacks.)

France, BTW, is still big into fuses, not circuit breakers. It's a sweet deal for fuse sales -- and fuse makers. Naturally, only French fuses will do.

Last edited by Tesla; 12/22/12 11:28 PM.

Tesla
Re: Running out of breaker space in new panels [Re: bossanova5] #208073
12/23/12 03:37 AM
12/23/12 03:37 AM
B
bossanova5  Offline OP
Member
Joined: Oct 2012
Posts: 13
L.A. CA
Thanks for the history lesson smile

Page 1 of 2 1 2

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
The_Lightman
The_Lightman
Orlando, Fl, USA
Posts: 49
Joined: August 2001
Show All Member Profiles 
Top Posters(30 Days)
Admin 20
sparky 16
Potseal 15
Popular Topics(Views)
243,574 Are you busy
180,374 Re: Forum
170,849 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.030s Queries: 16 (0.005s) Memory: 1.0254 MB (Peak: 1.2049 MB) Zlib enabled. Server Time: 2018-01-21 08:40:10 UTC