Overload Prtection For All Ungrounded Service Conductors 230.90

[InspectorElectric]

I have noticed that many of the multifamily dwelling I have been inspecting are basically using small multi-circuit disconnects for the house panels. The service conductors leave the meter base and are terminated directly into these small main lug disconnects. My understanding of 230.90 is that all ungrounded service conductors must have overload protection. My county however does not enforce this opinion, using Exception 3 in 230.90, so if the disconnect has less than 6 branch circuits it is allowed to exclude a main breaker.

My understanding is that we must have overload protection that is not derived from the breakers feeding the branch circuits of the panel itself.
Am I in error?

 

[GoldDigger]

The up to six branch and feeder breakers combined satisfy the NEC but only as long as the panel is listed for service use without a main breaker. Many are not.
Also if there is not upstream service disconnect the wires to each panel are still service conductors and must be sized and routed accordingly.

 

[jaggedben]

Are you saying that each unit has an unfused disconnect but no overcurrent device before a bunch of branch breakers for each unit? If so I agree this seems quite wrong. Although the way the rules are written differently for disconnects and overcurrent protection makes it rather confusing, I doubt anyone who wrote the Code intended to have many multiples of unfused disconnects. Every multi-unit building I can recall seeing had either a circuit breaker or a fused disco for each unit, and any branch circuits come after that.

You're using some terms that aren't clear to me, such as 'multi-circuit disconnect' and 'main lug disconnect'. (Pictures?)

 

[kwired]

Additional clarification may be in order on some items.

OP did mention "house panels" which possibly is only referring to the panel for the common areas?

If so, and there is no service disconnect ahead of this panel, you now have up to six service disconnects in this panel (if it is rated for it is another issue) plus one for each dwelling possibly giving you more then six service disconnecting means altogether.

If you have meter center with tenant breakers on each meter unit - those are your service disconnects as long as you don't have more then six that is acceptable. If there are more then six you still need a main (or up to six) service disconnecting means somehow.

 

[don_resqcapt19]

...
You're using some terms that aren't clear to me, such as 'multi-circuit disconnect' and 'main lug disconnect'. (Pictures?)

A main lug panel (often shown as MLO, Main Lug Only) is one that does not have a main breaker in it. The panel with no main, would be a "multi-circuit disconnect". Remember the code does permit up to six disconnects for each set of service entrance conductors.

The issue would be as stated in a previous post, that most small panels require a main to be listed as suitable for use as service equipment.

Many larger main lug only panels used in commercial occupancies are listed as suitable for use as service equipment without a main.

Another possible issue with the installation in the original post is the amount of unprotected service conductor within the structure and a possible violation of 230.70(A).

 

[jaggedben]

A main lug panel (often shown as MLO, Main Lug Only) is one that does not have a main breaker in it. The panel with no main, would be a "multi-circuit disconnect". ...

I'm certainly familiar with MLO panelboards. But "main lug disconnect" does not mean anything to me. (As opposed to what other kind of disconnect?) "Multi-circuit disconnect", to me, would mean a multiple-pole, single-throw device with more than one circuit wired to it. But it's not at all clear that's what the OP means.

I asked the OP what he meant because while I could guess at what he means, what he actually means could be quite different.