230.70 / 230.90

[bphgravity]

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.

 

[A/A Fuel GTX]

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.

If a main breaker was installed, it would have to be backfed but I do believe that would satisfy 230.70. In the second case, I'd say that 230.90 would not be satisfied as there is nothing protecting the service entrance conductors.

 

[Dennis Alwon]

I see no issue with 230.70. I do, however, see a code violation on 230.90(B) since there is no overcurrent protection on the service entrance. Use a DP breaker and you got it covered.

 

[augie47]

IMHO, it meets Code as wired.

 

[dcspector]

I see no issue with 230.70. I do, however, see a code violation on 230.90(B) since there is no overcurrent protection on the service entrance. Use a DP breaker and you got it covered.

yeah Dennis that is the way I read it as well.

 

[jerm]

IMHO, it meets Code as wired.

I agree with augie47. We don't protect service entrance conductors before the service disconnecting means, and in this case the 15 amp breaker is the service disconnecting means. Before the service disconnect it's pocos problem. Feel free to disagree, I've been wrong before.

 

[A/A Fuel GTX]

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.

I agree with you guys after doing more reading but couldn't that panel actually take 6 breakers and still be legal? Or is that dependant on the mfgr labeling?

 

[A/A Fuel GTX]

I see no issue with 230.70. I do, however, see a code violation on 230.90(B) since there is no overcurrent protection on the service entrance. Use a DP breaker and you got it covered.

Dennis......I'm a bit confused. What is 230.90(B) referring to?

 

[wirebender]

Looks like a good install IMSO.

230.90 says "Each ungrounded service conductor shall have overload protection."

Since there is no load, there is no possibility of overload, protection not required.

You might even say it has overload protection due to the fact that no load is attached. IMSO

 

[Smart $]

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

Yes, under the conditions stated and as long as the service entrance conductors in use, or to be used, have an ampacity of 15A or greater.

Do you see a violation?

 

[LarryFine]

I agree with you guys after doing more reading but couldn't that panel actually take 6 breakers and still be legal? Or is that dependant on the mfgr labeling?

In this case, it's a matter of the manufacture of the panel; it will only hold two breakers (or a 2-pole).

 

[Smart $]

In this case, it's a matter of the manufacture of the panel; it will only hold two breakers (or a 2-pole).

The label phrase, "...when not more than two branch circuit breakers are installed..." implies more than two breakers can be installed. For example, if two 2-pole breakers (i.e. two branch cirucits) can be installed, it is quite likely four 1-pole breakers could also be installed in the same slots

BTW, the possibilities of not more than two branch circuit breakers are:

• two 2-pole
• two 1-pole
• one 1-pole and one 2-pole
• one 2-pole
• one 1-pole

 

[Smart $]

I agree with augie47. We don't protect service entrance conductors before the service disconnecting means, and in this case the 15 amp breaker is the service disconnecting means. Before the service disconnect it's pocos problem. Feel free to disagree, I've been wrong before.

First, service conductors or portions thereof do fall under NEC jurisdiction when not under the control of the POCO, i.e. between service point and the service disconnecting means (SDM). And we do protect service conductors ahead of the SDM in that the overcurrent protection rating of the SDM cannot be greater than the ampacity of the service conductors. In other words, by limiting load side current we are in effect limiting line side current. However, this does not protect the service conductors under fault conditions ahead of the SDM, so it is only partial protection.

 

[gndrod]

Yes, under the conditions stated and as long as the service entrance conductors in use, or to be used, have an ampacity of 15A or greater.

Do you see a violation?

Possible lack of requirement for lighting per 210.70? rbj

 

[don_resqcapt19]

It is not suitable for use as service equipment as it is being used as a lighting and appliance branch circuit panel. This would be based on the 2005 code as there is no lighting and branch circuit panel defintion in the 2008 code.

 

[bphgravity]

Thanks for all the comments...

I do appreciate the discussion.