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OT Panel/Circuit Breaker Board Selection Help Needed

dalmatiangirl61

Diamond
Joined
Jan 31, 2011
Location
BFE Nevada/San Marcos Tx
I need to replace the single phase panel board in my home/shop, what is currently there was installed in 1960, the breakers are no longer available (except used), and did not come in anything higher than 70 amp. I have at least 200 amps coming in (probably more), it looks like 225 amp panels are common, there are some 250 amp panels, but quite a jump in price.

I need to have a 125 amp breaker to feed the rpc, and more circuits than currently available 36 @ 120v or 18 @ 240v. When looking at advertisements, if it says 42 space, is that 120v(single pole) or (double pole)240v breakers? I see one that says 42 space, 64 circuit, please explain this?

Looking around online this looks like it would suit my needs, yet currently out of stock. Is this a good choice or should I look at something else? https://www.homedepot.com/p/Eaton-BR-225-Amp-84-Circuit-Indoor-Main-Breaker-Plug-On-Neutral-Load-Center-with-Copper-Bus-BRP42BC225/307648489
 
For openers, I would go with SqD instead of CH because of the availability of equipment. All the panel builders have to go through U/L. Find out what the local electricians and inspectors favor. As far as the number of breakers of what size and such, that will have to be a careful reading of the literature.

Tom
 
I have a licensed electrician to do the work (weekend side job), choosing/purchasing the panel is up to me, we are skipping the inspector. There are no electrical supply houses locally, hardware store has some home grade units (sq D)but only 42 circuits, looks like ordering is my best option.
 
After looking at numerous descriptions it seems "spaces" is considered 2 pole, and circuits is single pole, so a 42 space is an 84 circuit panel, but I see many descriptions that say 42 space 42 circuit, and others that say something like 42 space 64 circuit, I'm thinking whomever wrote the ads was confused, but it has me a bit confused.

So it looks like 42 space on a 225 amp panel is all I'm going to get, I know sq D has 2 series, the homeline (don't want that) and the _____, my mind is drawing a blank.
 
Spaces is the number of slots that can fit a single pole breaker. So half that for two-pole.

Circuits is the maximum number of single-pole (120V) circuits you can have if you use as many tandem breakers as you're allowed, and fill the rest with single-pole breakers. This assumes zero 240V.

With AFCI/GFCI requirements, you can't use many tandem breakers.

Check how many amps your current main breaker is rated for - that's what you need to match. You may be able to go higher, but you probably would need to involve the power company and maybe run a new service cable. 200A is fairly common.
 
Spaces is the number of slots that can fit a single pole breaker. So half that for two-pole.

Circuits is the maximum number of single-pole (120V) circuits you can have if you use as many tandem breakers as you're allowed, and fill the rest with single-pole breakers. This assumes zero 240V.

With AFCI/GFCI requirements, you can't use many tandem breakers.

Check how many amps your current main breaker is rated for - that's what you need to match. You may be able to go higher, but you probably would need to involve the power company and maybe run a new service cable. 200A is fairly common.

There is currently no main breaker, not in existing panel, or elsewhere. There is a 400 amp fused disconnect, 3ph, yet currently only carrying single phase. Its a commercial building, previous owner removed 3/4 of the electrical system in the building, I am just trying to upgrade the 1/4 with service which is all concrete (floor/walls/ceiling), the only wood is room dividers and some furniture. No insurance, no banks to deal with if I burn the place down. Trust me, a moron with no previous electrical experience could do a better job than what is currently in place, and that has already been "approved" by an "inspector".
 
I second the Square D recommendation.

If you have to buy the panel, then watch out for your supplier. There are several different price sheets, you need to find a supplier that will sell to you off a reasonable business one...

Some of the others are higher, and the "nominal list" is astronomical just to let the contractor put that on the quote and bill.
 
I second the Square D recommendation.

If you have to buy the panel, then watch out for your supplier. There are several different price sheets, you need to find a supplier that will sell to you off a reasonable business one...

Some of the others are higher, and the "nominal list" is astronomical just to let the contractor put that on the quote and bill.

Yes, I see Graybar has some astronomical pricing. What is the commercial series called? I need that to refine my search. Most of what is coming up in searches is the homeline.
 
qo is the square d line you should get- it enables you to use 3 phase if you want to in the future. and then, qo breakers, too. The qo line is higher quality all around. You can get either home depot or lowes to order in the exact panel you want- go on the schneider website (they own square d) and look at the different panels. I think the biggest is 54 spaces.
 
Kris - I think you'll be best with a QO panel... and here's a thought-

Put in one panel, with main breaker from your main feeder. IF you need more circuits, or you have lots of circuits coming in from far away, put a big conduit out to a trough below, and install a subpanel... or several, that're all fed from that main.

When I did my place, I used the main panel with breakers going to subpanels located in places where it was most practical to bring smaller wiring, which reduced the amount of wire, and the amount and length of pulls from long distances. For each subpanel, you'll need conduit and appropriate 4-conductor wire (two hot, neutral, and ground), and the neutral and ground busses will need to be isolated on each subpanel, but I think you'll be really happy with how easy it makes 'scaling' the system as you rebuild.

Also... if you're working in an area, and need temporary power, bring up a 240v/50A 4-prong receptacle from the main panel. Get a range cord, connect it to a spare breaker panel (doesn't need to be very big) and mount a bunch of 120v and 240v receptacles on the sides with close nipples. Put an LED floodlight on the top, and a handle on the side, so you can carry it to wherever your work area is, plug in, and have plenty of tool power on hand.
 
Sounds to me like you need a better electrician, if he is making you responsible for sizing, layout, selecting, and procuring the gear. You admitted that you don't know what size your service actually is. It's more costly to do it twice, when the first go-round proves inadequate.

My recommendation would be to bring the entire capacity of the service into a wiring trough below the loadcenters, then tap off of that trough to feed as many panels as you require, to fulfill your needs now and into the future. For when you get around to wiring the rest of the building.

For a 125A circuit to feed your RPC, I would not recommend tapping off your loadcenter for a load that large. Many loadcenter brands will not even offer a 2Pole breaker that large, as with most, the bus stabs are only rated for 100A maximum on each bus stab, and that includes the breakers on the opposite side of the stab from the 125A breaker.

Better would be to install a 200A fusible disconnect switch fed from the lower service trough, mentioned above, dedicated to the RPC, and install fuses and wiring for your 125A RPC. This would relieve stress on the loadcenter bus and provide you additional circuit spaces in the loadcenter.

Then provide additional lower trough length, to install another loadcenter along it, when the first one becomes full and you need additional circuit capacity.

It's difficult to provide better advise without knowing what the existing service size is and how it's currently laid out and connected. That's the job the electrician should be doing. If you provided photos of the existing, we could better see what your working with.

As far as panel spaces, 42 spaces is the standard in loadcenters. Where you see panels labeled for for more circuits than advertised spaces, that means the use of tandem "twin" 1P breakers in each single space. Each loadcenter only allows a certain amount of tandem breakers to be installed, and they have a rejector mechanism to only allow so many, and in what spaces. It is recommended to avoid the use of tandems, especially in shop spaces, as the heat in the panel accumulates more when tandems are used.

SAF Ω
 
Tandems also have shown up to have issues with inrush current. We had a lab area in each office, and those were each fed their own circuit.... but at first it was via a tandem in some cases.

A regular variac would pop the tandem when it was turned on. Just about every single time. They all had to be moved to individuals, and the tandems reserved for things that were not tough loads. They were hardly good enough for that.

Lots of shop loads would be worse than just turning on a variac, which is definitely a big current spike, but not very long.
 
How about splitting into two panels ? Service drop feeds a disconnect which splits to one single-phase panel for your lighting and other loads, while the other hand feeds an rpc which then feeds a three-phase panel for the shop equipment ? Gives more flexibility ?

For three-phase, Cutler-Hammer is nice.
 
Sounds to me like you need a better electrician, if he is making you responsible for sizing, layout, selecting, and procuring the gear. You admitted that you don't know what size your service actually is. It's more costly to do it twice, when the first go-round proves inadequate.

He knows how to do the work, he works for a company that does both residential and commercial work, but they frown on employees doing outside work. All we are doing is changing out a panel to something modern that I can buy breakers for. I tapped onto main lugs and ran thru a 125a breaker last year and have been able to run the rpc, but only have 1 power cord, and its a pia to keep moving it.

I have never worked as an electrician, what is a trough? In my mind it is a container that horses and cattle drink from:D

If I can get more spaces than I currently have, there will be no need for twin breakers.

I consider this a temporary solution, more work needs to be done before I can bite the bullet and go for the full re-installation of power from the weatherhead to the top floor.

Pic 1 weatherhead
Pic 2 meter box and disconnect
Pic 3 overloaded ancient panel board, ignore the sketchyness, I needed a dedicated 120v circuit to run the shop heater last winter.
Pic 4 3 phase panel that the rpc will power, backside of 1ph panel is to right. Most of those 120v power cords feed my living space, if I had 2 empty spaces in board I would run a 240v circuit into living area to feed the large UPS system which would then feed lights (LED), computer, and TV.

RPC is a Phase-a-matic R20, I ran it at previous shop on a 70a breaker, mfr recommends 125A circuit for full power, data tag on unit states 50amps is what it consumes. I have more, and larger machines now so thinking I should set it up as mfr suggests.
 

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A "trough" is just a box type wiring enclosure that wires can be run/laid in when the cover is off. Typically can have conduit nipples in it connecting to load switches, sub panels, etc. Basically a big fat "conduit" with a removable cover, although they are square or rectangular in cross-section.
 
Here is you an example of a service using wiring troughs. This is similar in size to yours. It has one 200A 1Φ loadcenter and one 200A 3Φ loadcenter. On the right of the bottom service trough, there is room to add an additional nipple for another loadcenter or a large disconnect switch, if that becomes necessary.
IMG_20200922_202445255.jpg
IMG_20200922_202517071.jpg
The bottom trough is only for tapping the service entrance conductors, you can barley see the service conduit entering on the right end of the lower trough. Exterior mounted meter, similar to yours.
The upper trough is for branch circuits. Allows for mixing and matching branch circuit conduit loads to different panels. Having your panel flush mounted in an interior partition wall, makes this type of arrangement difficult to install. Surface mounting would lend to much more flexibility and easier circuit additions and modifications.

Comments on your photos.
It appears that at one time, the service was supplied with a 3Φ 4Wire aerial service drop. Then the underground to overhead mast wiring was converted to 1Φ. I don't see the wire for the third phase entering the service head, but there is a dangling wire, so can't tell for sure. It appears that the wiring here is set up for about 300A 1Φ 3W.
I don't see any straps on the pole mast and that's not very good for storms.
OverheadToUndergroundServicePole.jpg



On the exterior you have a CT (coil transformer) metering cabinet, with a side mounted cash register (meter). Judging from the underground conduit size, it again appears to be a 3" 300A service conduit. Tapped off of the left side of the CT cabinet appears to be a 2" conduit supplying a 200A disconnect switch. For reference in the future, if you wanted to tap your CT cabinet to feed another additional loadcenter. The new tap would require another service disconnect switch, grouped adjacent to the existing service disconnect switch.
UndergroundServiceMeteringCabinet.jpg

For the panelboard location it is not legal by today's standards to locate it in the path of the door swing. If you turned the panel around to face the other side, you would still have another door swing as a problem, complying with code. Maybe the door swings could be changed to avoid the dedicated electrical space infringement. Better yet would be to move the panelboard to the foundation wall, where your 3Φ panel is, and implement the trough wiring style as shown above, to get more circuit spaces by adding a loadcenter in the future. But if it were me, I would add another 200A fusible disconnect switch to the basement feeder dedicated to supplying the 125A RPC, and free up the panel circuit capacity for the remainder of your 1Φ loads.
PanelboardFront.jpg

SAF Ω
 
Here is you an example of a service using wiring troughs. This is similar in size to yours. It has one 200A 1Φ loadcenter and one 200A 3Φ loadcenter. On the right of the bottom service trough, there is room to add an additional nipple for another loadcenter or a large disconnect switch, if that becomes necessary.
View attachment 300034
View attachment 300035
The bottom trough is only for tapping the service entrance conductors, you can barley see the service conduit entering on the right end of the lower trough. Exterior mounted meter, similar to yours.
The upper trough is for branch circuits. Allows for mixing and matching branch circuit conduit loads to different panels. Having your panel flush mounted in an interior partition wall, makes this type of arrangement difficult to install. Surface mounting would lend to much more flexibility and easier circuit additions and modifications.

Comments on your photos.
It appears that at one time, the service was supplied with a 3Φ 4Wire aerial service drop. Then the underground to overhead mast wiring was converted to 1Φ. I don't see the wire for the third phase entering the service head, but there is a dangling wire, so can't tell for sure. It appears that the wiring here is set up for about 300A 1Φ 3W.
I don't see any straps on the pole mast and that's not very good for storms.
View attachment 300036



On the exterior you have a CT (coil transformer) metering cabinet, with a side mounted cash register (meter). Judging from the underground conduit size, it again appears to be a 3" 300A service conduit. Tapped off of the left side of the CT cabinet appears to be a 2" conduit supplying a 200A disconnect switch. For reference in the future, if you wanted to tap your CT cabinet to feed another additional loadcenter. The new tap would require another service disconnect switch, grouped adjacent to the existing service disconnect switch.
View attachment 300037

For the panelboard location it is not legal by today's standards to locate it in the path of the door swing. If you turned the panel around to face the other side, you would still have another door swing as a problem, complying with code. Maybe the door swings could be changed to avoid the dedicated electrical space infringement. Better yet would be to move the panelboard to the foundation wall, where your 3Φ panel is, and implement the trough wiring style as shown above, to get more circuit spaces by adding a loadcenter in the future. But if it were me, I would add another 200A fusible disconnect switch to the basement feeder dedicated to supplying the 125A RPC, and free up the panel circuit capacity for the remainder of your 1Φ loads.
View attachment 300042

SAF Ω


Yes, the building was previously supplied with 3 phase, when purchased the power co guys that hooked it back up said it was still available, conversation earlier this year with engineer tells me it is not available. They have done major upgrades and modernization to the system over the years, I was not always here and do not know if the 3ph transformer was replaced with a 1ph, or was not there to begin with. Both buildings to the south of me are desiring 3ph also, not sure when/if we will get it. Weatherhead conduit is buried very deep, won't know exactly till we dig it up, previous owner did the sloped driveway burying it deeper than originally placed, I'll throw a strap around top to secure it better.

Nothing is legible on data tag for the disconnect, someone sharpied 400A on interior, iirc the fuses are still 300A, upgrading that box has been discussed also, it has problems.

Removing either of those 2 doors is problematic, yes the wall where 3ph panel is would be ideal, what you don't see in that pic is the temporary wall to the left, in the 1960 remuddle a double doorway was cut through the 1' thick concrete wall, my plan is to fill it, but the concrete work in that room needs to be finished first, otherwise it has to go thru the 2 doors in pic.

Thinking, yes I could change the direction of swing on the left door in that pic.

Looking at pic 4 in post 14, would it be acceptable to put a trough over the panel, mounted to wall, split wires so 1 set feeds into panel, other set to a fused disconnect for rpc? Data tag on rpc says 50A, I think the 125A circuit is just for surge capacity, it would not be constant? It is roughly 60 feet from disconnect outside to the panel, putting another hole in exterior wall for another conduit gets back to "problematic" as it is 16" thick at the top, and there is another 1' thick wall to go through.

Mfr specifications can be seen here. Model R20 https://phaseconverters.phase-a-matic.com/Asset/RB.pdf

Currently nothing over 5hp, I think hardest starting machine is cylindrical grinder, when I get to it, maybe a 10hp compressor. 1 person shop, doubt more than 3 machines will ever be running simultaneously.



Thank you!
 
hardest starting machine is cylindrical grinder, when I get to it,
Sorry for the OT but ... get to it ! Once you start grinding, you'll never participate in another hard-turning thread.

Grinding is the schnizzle. You'll love it.

Watch for an id grinder, they are rare enough that you can make a little niche doing just that.

And thread grinding ... (everybody has a mill and a lathe)

I guess this won't work for you (looks like radio station KOW, kinda cool ?) but in California, if you say you're a farmer and need three-phase for pumping water, boom ! they're right on it. Even if you are on the edge of a suburb. Farmers got some pull.
 
Only thing the grinder needs is rewiring motors to 230v and changing out the heaters, other than that it should be ready to go. The "when I get to it" was about the compressor, once I have 3ph I can get rid of the big box screamer and get the 3hp Quincy running, the one I want to get running is the big Westinghouse, I will have to slow it to minimum rpm to use a 10hp motor, but I like a slow chugger:D
 








 
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