Emergency Disconnect

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Silky1

Member
Location
Ohio
Occupation
Electrician
Hello everyone, just wanted to get a better understanding of the Emergency Disconnect for one and two family dwellings. Does the disconnect have to be in one hand movement or can you have a meter/ main combo main lug and have several hand movements. Here how it would be for this installation, one breaker for the dwelling, and another one for the detached garage. Last question the surge protection would also be in this enclosure so that device would still be energized. Thank You
 
Silky1 said:
Hello everyone, just wanted to get a better understanding of the Emergency Disconnect for one and two family dwellings. Does the disconnect have to be in one hand movement or can you have a meter/ main combo main lug and have several hand movements. Here how it would be for this installation, one breaker for the dwelling, and another one for the detached garage. Last question the surge protection would also be in this enclosure so that device would still be energized. Thank You
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Unless there is a single main you cannot have 2 throws in the same panel. A meter main is fine but a meter with a main lug panel and 2 overcurrent protective device's would not be. You can have up to 6 disconnects but each must be in a separate enclosure.

The idea is to void having a main lug panel where you cannot de-energize the buss bar.
 
If the emergency disconnect(s) are the service disconnect(s), then the six handles rule in 230.71 applies. Neither the 2020 nor the 2023 code clarifies how emergency disconnects that aren't considered service disconnects are to be counted. I think if you had up to six disconnects grouped together outside, any combination of service disconnects and non-service-equipment emergency disconnects would be in the spirit of the rules. Both the 2020 and 2023 codes refer to the possibility of multiple emergency disconnects so it is definitely not the case that you are limited to one emergency disconnect.

The prohibition on multiple service disconnects in the same enclosure is a different rule change. Notably, there seems to be a loophole for multiple 'emergency disconnects' in the same enclosure.

Fwiw, I believe this will all be moot in the 2026 code where the stupid emergency disconnect rule will go away and service discos for one and two family dwellings will simply be required to be outside.
 
Dennis Alwon said:
Unless there is a single main you cannot have 2 throws in the same panel. A meter main is fine but a meter with a main lug panel and 2 overcurrent protective device's would not be. You can have up to 6 disconnects but each must be in a separate enclosure.

The idea is to void having a main lug panel where you cannot de-energize the buss bar.
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That explains what he was asking. 👍

I’ve never seen a meter/MLO combo panel. Do they even exist?
 
Seven-Delta-FortyOne said:
That explains what he was asking. 👍

I’ve never seen a meter/MLO combo panel. Do they even exist?
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Yes,
They were commonly used for houses. I think they were 12/24 slots - They'd put the entire house branch circuits and a dryer fed to a sub panel on a 90A breaker with #2AL. Then the stove, AC and range outside in the main lug panel (Or something similar)
If they had 5 full size 2 pole breakers, sometimes a unscrupulous person might put 4 singles in the last two slots making it a violation of the six disconnect rule.
 
Seven-Delta-FortyOne said:
That explains what he was asking. 👍

I’ve never seen a meter/MLO combo panel. Do they even exist?
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Buck Parrish said:
Yes,
They were commonly used for houses. I think they were 12/24 slots - They'd put the entire house branch circuits and a dryer fed to a sub panel on a 90A breaker with #2AL. Then the stove, AC and range outside in the main lug panel (Or something similar)
If they had 5 full size 2 pole breakers, sometimes a unscrupulous person might put 4 singles in the last two slots making it a violation of the six disconnect rule.
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I have never seen a meter combo with 12/24 loadcenter. (6) 2-pole breakers was the maximum allowed so it wouldn't make sense to offer 24 circuits. Square D used to make one that did have a 12 circuit loadcenter but it was not listed for tandems/twins.

The other manufactures (Challenger/Cutler-Hammer/Eaton, Siemens, Crouse-Hinds & GE) made meters combos that had 4/6 loadcenters so they would take (2) 2-pole breaker or (1) 2-pole and 1 quad breakers.

I remember in the 80's The city of San Jose failed several large tract developments because the EC used GE equipment. Instead of the breakers being next to each other like the other manufactures GE had their spaces on top of each other. This resulted in the top breaker having the handle off when up and on when down.
 
curt swartz said:
...Square D used to make one that did have a 12 circuit loadcenter but it was not listed for tandems/twins.
...
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That was a 12 space panel intended for a max of six 2-pole breakers. You weren't supposed to put 12 single pole breakers in it; the fine print on the label said max of six handles, for people who read the fine print.

I've also seen some older 8 space QO MLO meter mains.

Fairly common around here until even about ten years ago was a 4 space panel with two spaces that would take quad/tandems. (Cutler-Hammer/Eaton, or Murray). That physically restricted the disconnects to max six single pole or three two-pole. Commonly contained two service disconnects, one for a sub and one for the A/C. Nice when we could quad the A/C breaker to fit a solar breaker.
 
jaggedben said:
That was a 12 space panel intended for a max of six 2-pole breakers. You weren't supposed to put 12 single pole breakers in it; the fine print on the label said max of six handles, for people who read the fine print.

I've also seen some older 8 space QO MLO meter mains.

Fairly common around here until even about ten years ago was a 4 space panel with two spaces that would take quad/tandems. (Cutler-Hammer/Eaton, or Murray). That physically restricted the disconnects to max six single pole or three two-pole. Commonly contained two service disconnects, one for a sub and one for the A/C. Nice when we could quad the A/C breaker to fit a solar breaker.
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Correct. That is why I questioned the panel that Buck mentioned having a 12/24 buss.

I have seen 12/24 main lug loadcenters used under a stand alone meter socket so the original installer and anyone adding breakers in the future had to be aware of the 6 disconnect maximum. I have never seen a combination service entrance device without main breaker accept more that (6) 2-pole breakers.
 
Dennis Alwon said:
@curt swartz I believe Siemens, then ITE, made 12/24 wp ML panels.
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Weather proof (3R), yes. Not combination service entrance devices without a main breaker.

I have only seen and used the Siemens that had a 4/6 load buss.

As I mentioned, the NEC only permitted up to 6 breakers so a 24 circuit load center would not make sense.
 
curt swartz said:
Weather proof (3R), yes. Not combination service entrance devices without a main breaker.

I have only seen and used the Siemens that had a 4/6 load buss.

As I mentioned, the NEC only permitted up to 6 breakers so a 24 circuit load center would not make sense.
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The panel had 12 spaces. I believe the idea was to use it with 6 dp breakers but I am quite certain that twins could be used and some inspectors would try and turn it down because someone might add another breaker. They were not allowed to turn it down until someone did actually and more breakers.

When I first moved here almost every home was wired with them. The development where I lived when I first got here were all ~1200 sq. foot homes. All the homes there were wired with these panels. I am 99% sure of it but it isn't worth arguing about.
 
jaggedben said:
Yes but that's not a meter main combo obviously. It will mostly be used as a subpanel. And if you read the label, it's only suitable for use as service equipment with a main breaker installed.
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Not back then. I am sorry if I misunderstood. I did not think we were talking about meter mains without the main. Certainly you wouldn't find it now.

Also back then the panel was suitable for service without the main. Again I am talking many moons ago.
 
Back then they called it a service and equipment panel and you were not allowed to install branch circuits or lighting loads in the panel. I think it was 408.39. It changed in 97 and allowed branch circuits . It still had to be 6 or below motions of the hand.
 
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