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mfreeland 11-29-2010 07:42 PM

Substituting a Murray for Siemens branch breaker
I recently purchased a Milbank Meter Main/Breaker Panel combo to replace an aged outdoor meter and to supply juice to a new barn. The main breaker in the combo main/breaker panel is a Siemens 200 amp QN2200RH (22 kAIC) for which they say on the label that branch breakers should be Siemen's type QP or QPH. The box doesn't have pass through lugs and I'd rather not use tap connectors on the load side conductors going to the house. Also, I like the idea of being able to shut off the underground juice to the barn between my utility pole (near the house) and the barn 240' away in case I need to do some digging in the yard. I found a very good price on a Murray QP 200 amp double pole branch breaker (10 kAIC) that looks like it would plug right in to the breaker panel using 4 of the 8 available spaces (2 adjacent and 2 opposite). I understand that Murray and Siemens breakers are identical except for branding and everything I have found on-line would support that notion - the literature I've found on the Siemens QN2200RH and Murray MPD2200R both share identical (I mean identical) layout/style, type font, images and the graphs of time-current characteristic curves for the 2 breakers is also identical. In fact, the Murray literature (including the TCC graph) is copyrighted by Siemens. Can anyone imagine my having any problem using the Murray breaker in the combo panel to feed my barn even though it apparently isn't series rated for the Siemens? Also, am I correct in assuming that there should be no problem in using the Murray branch breaker w/ only a 10 kAIC circuit interupting rating downstream from the 22 kAIC Siemens main breaker? Thanks

emolatur 11-29-2010 09:25 PM

Oh boy. I hate this question. Code says, basically, you can't do it. I always do. I am a bad, bad midget.

Alright here's the deal: you have to install things per the manufacturer's instructions. If the breaker or the panel claims to be legal for each other, then you can do it. Otherwise, you can't, whether it fits or not.

Several brands (Murray is one, I can't remember the others, but if someone mentions them I probably will) are actually made by the same company. Guess what? They're not listed for each other. Thus, even though you may buy the exact same breaker from the exact same factory, with all of the same identical internal (and external!) components... since the sticker affixed to it claims the other brand, you can't use it! That doesn't make me happy. It makes me scream and cuss now and then, actually.

Murray is usually junk anyway.

mfreeland 12-01-2010 06:54 PM

Then Siemens would be junk too? Please explain. Thanks

frenchelectrican 12-01-2010 09:15 PM

Not always be junk however as emolatur explaing about cross brand name and I know Murrphy do use couple other name brands as well but one ugly gotcha is you really have to follow the listing on the load centre.

I don't have issue with Seamens breakers they are allright to me noting fancy for moi.

But if the inspector see crossbrand they will say something about that unless the inspector is aware with few diffrent listing.

I know I did have a list what it can be crossover but I don't have the listing with moi at the moment so I will have to dig up and find it.

As long it do listed in for that load centre the inspector will have no issue.

{ you may want to get a copy once I find it and keep it in your load centre }


LyonsElecSupply 12-01-2010 10:04 PM

By chance is your meter center a U5168-200 (maybe some other designators?)

If it is, you should have lugs at the bottom for 200 amp 4/0 alum.

Now as far as your subfeed goes YOU MUST put that on a disconnect rated for the wire. Im guessing you want to run 200 to your house and 200 to your barn by your question. If you are running 200 Amp to your barn, I will ask you these questions: why do you need 200 amps in a barn, and what size wire were you planning on burying...........At 240 foot, you are looking at around 300 kcmil (which is usually available only single wire runs) to support a 200 amp service.....Most 200 amp breakers dont allow for anything larger than that........

My recommendation is this: get a 2 pole 125 amp breaker and bury somewhere around 2/0 urd/use. (I dont have my trusty chart in front of me atm)

As emolatur said, using breakers from one manufacturer in another device, they MUST be UL listed for the application. If not, the inspector can deny you. Now, that being said if it is a U5168-200 housing, you can use Murray, ITE/Siemens, Cutler Hammer BR series and (I think Square D homeline)

mfreeland 12-02-2010 10:48 AM

Yes, I am using a U5168-200. I was planning on running 200 amp to the barn only because someone suggested I go for as much amperage as I could - you know, the "Go big or go home!" mentality - and they believed I could do so using 4/0-4/0-2/0 AL URD. Truthfully, I probably wouldn't ever need 200 amps. I plan on subdividing the barn to include 2 workshops, each of which would have a 240 V electric heater requiring a dedicated 30 amp circuit. I can imagine adding a large air compressor requiring a 40 amp circuit. The rest of my needs would only be lights and standard power tools, table saw, planer, etc. Obviously it is unlikely that I'd be using a lot of these simultaneously (perhaps, even unlikely that I'd be heating both workshops simultaneously). As far as my U5168-200, my understanding is that the bottom lugs of this will be occupied by the 3/0 CU lines going back up my utility pole to supply the house and that my only option for adding underground service was a from a branch breaker on the panel or tap connectors to the 3/0 CU going back to the house. But, w/ the tap connector arrangement I'd have to cut off power to the house to cut off underground power to the barn in the event I wanted to do some digging in the yard - and a future fence is a possibility.
As far as "listed" branch breakers for the U5168, for a Siemens QNRH main breaker (22 kAIC) - and mine is a QN2200RH - they list only Siemens QP, QPH. The other makes that you mention are only listed for Siemens QNR main breaker (10 kAIC). I understand that sometimes Siemens/Murray crossovers are permitted. I couldn't find a Siemens QP 200 amp branch breaker and I was afraid that anything smaller wouldn't be capable of handling the 4/0 AL (212 KCMIL by my research) as well as the Murray MPD2200. I guess I mistakenly believed that it was more the distance I was going than the amperage that was requiring of the larger wire (I understand that the 2 are obviously related but interpreted what they told me as the distance being more limiting). If you believe my needs would be met by 125 amps and 2/0- 2/0-#4 AL URD, I'd be happy to save a couple hundred bucks and work w/ smaller wire! But, if I were to go w/ my original thought using the Murray MPD2200 and 4/0-4/0-2/0 AL URD would you see a problem w/ a 10 kAIC MD-T rather than a 22 kAIC MD-HT? Thanks

mfreeland 12-02-2010 10:52 AM

Where might I possibly find a list of acceptable Siemens/Murray crossovers if such exists? Thanks

LyonsElecSupply 12-02-2010 03:48 PM

I should be able to help you here.

I sell that meter center and understand what you are doing now. To address your second question there is no "crossover" list, the breakers must be labeled and UL Listed for use in the said enclosure OR the enclosure must indicate what is acceptable in said enclosure. One of the two. To the best of my knowledge you can use Siemens QP, Cutler Hammer BR and Murray MP.

You can go the route you intend to, but it will be at a substantial cost to you. IF YOU DECIDE ON 200 amps.....This is the cost effective way to do it: get a tangle box (metal or pvc) large enough to accomodate the wires and tap off your urd to that. Remember you will need to have dual rated taps Al/Cu and (i believe anti oxidant on the wires) Run pvc to the ground and terminate the PVC underground to run URD to the Barn.

As far as the breakers go:

I know for a fact that the u5168-200 CAN accept Cutler Hammer Series BR breakers. With this information I suggest you not go with a 200 amp service. You are going to pay an arm and a leg for service you wont use or need. You can get a BR2100 (2 pole 100 amp 10kaic) for about 45 bucks. I suggest you go with about 80 amps to 100.

As far as your wire:

I did the calcs and you CAN use 4/0 alum in a 240' run. The voltage drop at 200amps is under 5%. 4/0 is acceptable as service entrance at 200 amps, however its whatever your AHJ says the barn is. If it is a branch then you might not be able to use it and will have to derate the circuit. Dont forget that in this set up you need 4 wires to the barn for your isolated ground.

If you go to #2 URD/USE then I suggest using an 80 amp breaker. This should suffice unless you are planning on a large electric heat load or multiple large motors starting and stopping.

Honestly, the cheapest easiest solution is a 2 pole 80amp at the Combo unit, and running 2/2/2/4 URD/USE combo. Thats what I would do. Like I said unless you have a HUGE electric heat load you DO NOT need 200amps out there. 2/2/2/4 USE/URD will give you just at 5% voltage drop at 100% load. Normally you do not want to run a 100% load, you want to stay around 80% of the OCPD. This will give you 64 amps (15.360 kW) or so of continuous available load.

LyonsElecSupply 12-02-2010 04:50 PM

Ok I fully reread your post. I saw the 2 heaters and 40amp compressor.

Those heaters are probably 5.6 kW each which is about 23 amps, x2=46a continuous load. I wouldn't worry about having an 80 amp service with this set up. I honestly believe this is the way to go. You MIGHT have an issue if both heaters are on fully and your compressor kicks on.....

As far as your allowed breakers go, here is the spec sheet for said combo unit:

Your series rating as UL listed on this enclosure is 10kaic with anything other than siemens it looks like. This might be denied by the POCO as insufficient.....

the way I understand it is that the Main breaker protects to 22k from the breaker to the bus. From the bus to the branch is only 10k.......The AHJ can say this is denied due to insufficient series rating. Again this is an issue you need to talk to the POCO or AHJ about.

Good news is that they make a QP280....This will allow you to keep your series rating.

I wouldnt worry about anything over 10kaic for residential.

mfreeland 12-02-2010 09:47 PM

I am very gateful to you and appreciate all your advice/recommendations. I had an electrician out this afternoon and he concurred that 200 amps was excessive and by his calculations the 4/0 AL came up a bit too small for a 200 amp/240' run. He thought that 100-125 amps would be plenty. Like you, he also said there would be no problem using the other non-Siemens breakers and said he liked Square D Homeline. A HOM2125 breaker won't be a problem to find. One last question for you though. You say I need to run 4 wires. In talking w/ him it seems only 3 wires was ever mentioned. He said I would need 2/0-2/0-1 AL. The difference may lie in my not having fully described what I planned to do inside the barn. At the service entrance of the barn will be another load center w/ a 125 amp main and 16-24 circuit branch panel. Does that make more sense or do I need to revisit things w/ the electrician?

LyonsElecSupply 12-02-2010 09:53 PM

Not a problem, good luck with your project.

I would recommend Cutler Hammer, but Square D is a close second.

He should know to put a 4th wire at the barn. From my understanding of the code, the barn is a detached structure that is being subfed from the main panel (disconnect meter combo)

If the other panel is NOT "in sight" (the code defines this as less than 50 foot and visible when standing at the panel) you MUST have a disconnect at the other end. Also, ANY SUBPANEL must have an Isolated ground (4th wire) ran to it, regardless of its location. Because the barn is a DETACHED structure you also must drive one ground rod at the barn for that panel.

Now, he might be getting around this by driving 2 ground rods, but I am not sure.

I was always told any subpanel gets 4 wires......

Im not advising arguing with the electrician, but if hes pulling a permit, you may get rejected resulting being put into a bit of a bind.

Maybe some electricians or code experts know a way around not running a 4th wire to a subpanel on a detached structure.

emolatur 12-03-2010 01:59 PM

For the record, homeline fit almost everything, and they're the only ones I always have handy because of this.

The house I'm working on right how has some Siemens breakers, tandems at that, which the proverbial last guy shoved in the GE panel. Seem to be of decent quality, I'm leaving them.

The Murray "junk" breakers I speak of are very noticeably poor in construction, handle operation feels "spongy" and weak.

Truth be told they're all (except QO and GE's slims... and technically there's still a company up in Canada making those blasted stablok things) using the same breaker size and bus connection now, with slight variations to keep the competitors breakers from fitting. The internal mechanical guts differ from one brand to the next, and my complaint about the Murray breakers is related to this.

frenchelectrican 12-03-2010 11:41 PM


I can understand the situation however as Lyons mention the code related issue due majtory of the modern code cycle required that it have to be 4 conductor feeder from central location aka pole disconnecton panel but the quirk is where are you located due some states still use old 1999 code some state still use 02 NEC code cycle and some use 05 or 08 NEC code cycle so if it was later than '99 then it must be 4 wire feeder.

I know couple places don't really enforce the code much.

But the safest methold is make sure you follow the latest code so you will not have issue and who did pull the permit for this type of work you or the electrician ?? If the Electrician do pull the permit then they should know which code cycle they fall in.

If you have any doubt just check at county office to find out the latest scope on code { building dept or inspection dept }

And yes Lyons is correct you will need two ground rods.

The only time I know they can use the three conductor if you have no metalic path between the two buildings it may use that but myself I rather not use that methold due I feel more safer to just run 4 conductor and be done with it { I know it may add cost little more }

And for barn power requirement most case I useally run into the barn { non livestock set up } or garage most use anywhere from 60 to 100 amp subpanel size it super rare for me to see 200 A there unless have decked out machine shop or serious hobbyist.

If you did have 120mm˛{ 4/0 AWG} conductor for that distance if you have alum verison the 125 amp breaker will not have any issue at all but only one nice gotcha is the termation size that will bite ya so you will have to make a reducing splice or fingers { this part you will need a hydrallic crimper on it } but for reducing splices just get few polairs connectors and downsize to 50mm˛{ *1 Awg } copper if you going to use 125 amp breaker but if use alum in the same size then you have to kick it down to 100 amp breaker.

Hope that will clear up few details.


LyonsElecSupply 12-04-2010 08:34 AM


There is a common industry "blade" style bus. Cutler hammer BR, Homeline, Murray, QP Siemens, Westinghouse, some Challenger, a GE series (unknown which), and Gould. I think theres a few others.

You referenced carrying Homeline to drop into panels that carry this bus. Keep in mind that doing so IS NOT permitted by most inspectors. The breakers MUST be UL listed to be permitted. Now, do most inspectors really care? Na. Do you pull a permit to switch a breaker? No. Will it work fine? Heck yes. Id do it.

But if you are a nit picky perfectionist, look into carrying a set of "Listed" breakers on your truck. Cutler Hammer CL series are such a set.

emolatur 12-04-2010 09:04 AM

Lyons, I know this.

Come to my area and ask for a permit to do electrical work. You will be laughed at. You pull permits to construct a new building, or an addition over a certain size, and that covers the whole job, electrical included. Rewiring an existing structure? Don't waste the code enforcement department's time.

Inspection? That's pretty much done when the power company comes out to hook you up. "Got a main breaker? check. Ground rod(s)? check. Here's your power."

Our "code enforcement" department didn't exist 5-10 years ago. We had a couple landlords in town that the municipal officers didn't like. First they tried to take their buildings through BS applications of tax laws (and failed, mind you), so they created the code enforcement department, which proceeded to condemn half the apartment buildings in town over nonsense repairable issues.

MANY buildings here still have screw-in fuses. A good number have indoor metering. Most still have some knob&tube.

I think it's obvious where I'm going: not one person has ever complained about my use of homeline breakers in every single non-QO/FPE/Zinsco panel. :)

Re the GE panel. Mine's a "Powermark Gold", takes their breakers (including the slims) and homeline/etc also.

THQL are GE breakers that fit this "industry" bus. Sorta. The Bryant panel in the garage doesn't like them, and I haven't bothered to figure out why (just gave up and shoved homeline in there).

I'm still at a point in life where I'm curious enough to figure out why things do or do not work and are or are not allowed, rather than just accepting it. :)

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