For the follwing scenerio, are the requirements of 230.70 and 230.90 being statisfied?

240V, 3-wire, single-phase service. From the meter socket enclosure, two ungrounded conductors and one grounded conductor are brought to a 60A rated 2-pole main lug panelboard. There, one single pole 15A breaker is installed to supply a single piece of equipment. No breaker is installed on the other leg.

In addition to this arrangement, the panelboard is marked with the following label:

This panel is suitable for use as service equipment when a main breaker is installed or when not more than two branch circuit breakers are installed and is not used as a lighting and appliance panelboard.

Thanks.

Bryan- I think that what you are describing could very easily be a Lighting and Appliance branch circuit panel board per 408.34 and if that's correct then there is a violation.

I'm carious, can you explain your answer George?

Well- Is it a Service disconnect? No because it doesn't contain the ability to disconnect the Service conductors. It is not a power panel due to the definition of a power panel found in 408.34 but it might be a Lighting and Appliance branch circuit panel board based on the same article. either way it is a code violation. Kinda a weird installation.

There is an outside chance that it might qualify for a single circuit Service Disconnect per 230.79 but we should have more information, particularly about the service conductors and their sizing.

Geroge

Thanx for the explanation. I just could not wrap my noodle around your post.

Byran

Without further info, I would say you are good providing the breaker is sucured in place (408.36)(F). A single breaker can be used as a disconnect. 230.79(A). The problem is the second slot can not be use 230.79(B) unless a minimum breaker of 2 pole 30 amp breaker is used and a panel was installed.

If the disconnect is powering 1 circuit then it just passes muster. Future needs can be a little more of a problem however if there is no need for future addition then you got an economical service.

Thanks for the comments.

The breaker is is not being backfed so 408.36(F) wouldn't apply.

I know all service conductors require a disconnecting means and all service conductors require overload protection.

However in this case, there are no loads that will overload the unused leg and there is nothing actually being disconnected even with a breaker installed on that unused pole.

The code permits an MLO to be used as service equipment under certain conditions. I just not sure what the correct solution for this scenerio is.

The service described is very common, most traffic lights & cable TV system power supplies use a service like this. Although many only have 1 leg (120v only), quite a few are pulled with both legs to the breaker box, usually a main lug panel with 1 15 to 30 amp breaker.

This is exactly what my question is refering to, a TV cable pedestal.

With the second leg brought to the service, does it not require a disconnecting means and overload device.

If the other slot is blocked out and the other leg is not going to be used, why waste the money? It would serve no purpose what so ever. If the 240 were needed in the future, that the existing breaker would have to go bye-bye any ways. The problem with code inforcement is understanding the intent of the code. If just the word of the code was enforced then everyone would be doing it. This what drives me bonkers with home inspectors. Unless they had real life skills, there are only book smart at best which is not a good thing in the trade. (I'm getting off my soap box). When rather I am wearing my inspector cap or pulling wire, I go with the intent of the applicable codes.

I understand the intent, but intent is not enforceable.

So, it goes back to the true point of the original question.

Where does the code permit the disconnecting means and overload protection of a service conductor to be eliminated simply because the conductor is not being used at the time of installation?

Where in the code does it say that the service disconnect and the OCPD has to be seperate? The intent of the code IMO is met. Outside of running up the cost to the owner, how would a seperate disconnect provide additional protection or safety? The NEC is only about safety, not future capacity, efficiency or convienience.

It doesn't ?



I realize that, however I am not asking if there needs to be a separate disconnecting means. There is no service disconnecting means for one service conductor? I don't see where that is permitted.

The actual soultion is really the instructions labeled on the panelboard enclosure. It clearly states that the unit is not suitable for use as service equipment unless a main breaker is installed or with 6 disconnects or less when not used as a lightning and appliance panelboard.

It is be used as a lightning and appliance panelboard therefore a main is required in order for the equipment to be used as a service.

This has been a rather interestng discussion. I have posted this question on four separate Forums and have received completely mixed answers of yes and no. All good arguements either way.

230.79(A)

230.79 identifies the required rating of the service disconnecting means. There isn't one on the service I describe.

Or I should say, not one for ALL service conductors installed.

230.79(A) is for a single circuit service. If the is not applicable to your topic, what do you have that we do not know yet?

It's not a single circuit service. It's a 3-wire service.

Let's try another example. Say this was a 120/240V delta service. It is quite possible the B phase (208V) will have no loads at all. But, a service disconnecting means and overload device is required for that conductor. Right?

Back on my original question, doesn't 230.71(B) state that single pole units aren't permitted on multiwire circuits unless 2 or more are handle-tied together?

So again, where does the code allow service conductors to be installed and terminated at a panelboard without a disconnecting means and overload protection.

I'll begin by saying I have approved many installations like this for Traffic signals etc.

To satisfy the exact Code would two 1P15 breakers with a handle tie and labeled service disconnect, and the load on only one of the breakers work ? (Waste of material)
If that is too complex just remove one of the line side conductors. (Cheapens the job)

I'm dealing with guys that want to bury MC cable.

Terminate the second phase in the meter can, don't bring it to the panel, backfeed the 15a breaker with a clip and "Service disconnect" sticker. connect the load to another 15a breaker if you are a purist. (or the MLO lug? )

The solution Greg states is the way the manufacturer wants it done and the way I believe the code is worded.

If the intent is that the service disconnect removes power from the panelboard rails (not an unreasonable interpretation) backfeeding the 15a breaker is the only way you can do it. The operative question would be, with a single connected load, could the load be directly connected to the MLO lug, protected by the "main".

First of all are you even sure a permit was pulled. Up here, in the northeast, the cable company doesn't pull permits to put those boxes up, unless they have to. Most of the time it is low bidder. They are probably using parts lying around a shop.