NEC 2020 Code change 230.71

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mwm1752

mwm1752

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Sometimes the revised code just doesn't add up or I am not seeing the the interpretation correct.
230.71(B) basically eliminated - up to six service disconnecting means for a service disconnect "grouped in a single enclosure". There are conditions 230.71(A)(4) switchgear with up to six disconnects for the service disconnect is allowed as long as the disconnects are located in a separate compartment. Those 2 statements have me interpreting the separate compartments are for each disconnect and not attached to a buss side by side.
I believe 230.90(A) exc. 3 describes over current protection of service conductors in the case of 230.71(A)(4).
Now look in the Handbook Exhibit 230.23 & I see up to six service disconnecting means for a service disconnect "grouped in a single enclosure". The visual is very deceiving & when enforcing inspections in the field contractor rely on NFPA handbooks for clarity. I am thinking this was overlooked by NFPA and the illustration was not revised or maybe I am missing something here.
 
Yes , multiple disconnects in the same enclosure is gone from the 2020 NEC. I don't have a 2020 NEC Handbook to look at but the Handbook is notorious for errors such as you describe. There have been many over the years. Keep in mind that the Handbook is not the code and can't be used as such.
 
One of the reasons for the change was the rule in the 2017 NEC that required a barrier on the line side of main breaker. In a MLO panel with the 6 disconnects, there was no way to install a barrier, and the bus would always be hot. The bus would have higher level of fault current, compared to the secondary side of a main breaker.
 
I think you mean the commentary in the handbook is not code -- The actual articles inside are. I was just wondering if I missed something. though exhibits are a visual reference an incorrect illustration makes a teaching moment difficult for the young apprentice & impossible for the old goat master sometimes :cool:
 
mwm1752 said:
Sometimes the revised code just doesn't add up or I am not seeing the the interpretation correct.
230.71(B) basically eliminated - up to six service disconnecting means for a service disconnect "grouped in a single enclosure". There are conditions 230.71(A)(4) switchgear with up to six disconnects for the service disconnect is allowed as long as the disconnects are located in a separate compartment. Those 2 statements have me interpreting the separate compartments are for each disconnect and not attached to a buss side by side.
I believe 230.90(A) exc. 3 describes over current protection of service conductors in the case of 230.71(A)(4).
Now look in the Handbook Exhibit 230.23 & I see up to six service disconnecting means for a service disconnect "grouped in a single enclosure". The visual is very deceiving & when enforcing inspections in the field contractor rely on NFPA handbooks for clarity. I am thinking this was overlooked by NFPA and the illustration was not revised or maybe I am missing something here.
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Did you mean exhibit 230.22 ? In the 2020 Handbook.
 
Buck, No that exhibit shows it correctly -- 230.23 is an exhibit illustration for service disconnects that is no longer compliant. (The context is about conductor/ OCPD ratings) but the illustration had not been changed from previous codes. They should have updated to switch gear having separate enclosures like 230.22
 
mortimer said:
So a temp. service with main lugs is now a violation?
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Yes, that is a violation of the 2020 code. The only type of service equipment with main lugs that would be permitted is things like switch gear with a main bus, but each service disconnect in its only physical compartment. Another thing that is a violation is the typical meter center with 2 to 6 meters and breakers. The breakers are not in separate compartments, making that type of equipment a violation of the 2020 rule.
 
So exhibit 230.22 is still code compliant? Because it looks like you would have to take the cover off of three disconnects at one time.
 
Don, has a good point. I believe some meter/main bank do have separate compartments behind the single cover & some do not. I am understanding a barrier between each breaker could work.
 
mwm1752 said:
Don, has a good point. I believe some meter/main bank do have separate compartments behind the single cover & some do not. I am understanding a barrier between each breaker could work.
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Not sure if some have individual compartments or not. The ones used around here do not. The Standards Technical Panel for the UL standard that covers meter centers is looking at modifying the standard to comply with the 2020 NEC requirements.
 
Don,
Probably thinking of older ones that had KO's in the back & was a big pain to line them up. Hair is turning white fast nowadays
 
mortimer said:
So a temp. service with main lugs is now a violation?
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I bet many were never compliant without a main breaker installed. Code yes they could have six mains, but if you read the instructions it likely says something like "suitable for use as service equipment when main breaker is installed".

A big majority if not all "load centers" I believe have similar language in their instructions.

There are some I-Line panels that specifically have instructions that permit up to six main breakers to be installed in a main lug version.
 
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