No main breaker

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karn

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This is MDP, there is no main breaker in this EDC, this is the first time I seen something like this that does not have a main breaker, is this code legal? There is a main disconnect outside and a transfer switch on the other side of the building
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(Surge protection device near bottom, not the main breaker)
 
karn said:
This is MDP, there is no main breaker in this EDC, this is the first time I seen something like this that does not have a main breaker, is this code legal? There is a main disconnect outside and a transfer switch on the other side of the building
View attachment 20927
View attachment 20928
(Surge protection device near bottom, not the main breaker)
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What do you find objectionable and why? Code section?
 
There's not exactly a code section I know of that would object to this, but there's also not a code section I know of that would say it's permissible, from experience I just expected one to be there
 
karn said:
There's not exactly a code section I know of that would object to this, but there's also not a code section I know of that would say it's permissible, from experience I just expected one to be there
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Then you have just achieved a new experience...

It's done all the time. If for some reason someone wants the Main to be located outside, as in your case, then there is no need for it to be duplicated again inside. USUALLY people just put the Main in the panel because it's cheaper that way. But they may have had a totally legitimate reason to put it together like this.
 
karn said:
There's not exactly a code section I know of that would object to this, but there's also not a code section I know of that would say it's permissible, from experience I just expected one to be there
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Think about what is the point of main lugs only options if you can't ever use them?

If bus is properly protected by upstream OCPD then no additional overcurrent protection is necessary.

If supplying a second building mains are often installed because you still need a main disconnect for that separate building. Six disconnect rule can apply though.

Some may want mains in nearly all panels for safety procedure reasons, but this is design issue not code driving that.
 
I agree with above.. I want a main breaker so I do not need to go find the main breaker elsewhere to work on my panel, but ...
if the main breaker is near the meter, to keep any backfeed from my backup systems from affecting the local power company, then it complies. The panels in the house can be shut off, for working on, and the lockouts put in place, not so much harder than walking into the basement to do it...

just easier to install the lockouts outs on the panel I am working on, and less exercise..lol
 
Adamjamma said:
I agree with above.. I want a main breaker so I do not need to go find the main breaker elsewhere to work on my panel, but ...
if the main breaker is near the meter, to keep any backfeed from my backup systems from affecting the local power company, then it complies. The panels in the house can be shut off, for working on, and the lockouts put in place, not so much harder than walking into the basement to do it...

just easier to install the lockouts outs on the panel I am working on, and less exercise..lol
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If you ever have to change the panel itself out, the main outside may save you some extra steps and down time.

The Main outside kills the power so there is no power in the MDP at all unlike having a main in a panel.

The Main outside has nothing to do with keeping the power from backfeeding onto the power company's lines. That's the X-fr Switches job.

The Main outside allows the fire department to dump the power feeding the MDP, killing the power inside, where as a Main in MDP would not.

There's actually more pros to this type of installation than there are cons.

JAP>
 
kwired said:
Think about what is the point of main lugs only options if you can't ever use them?

If bus is properly protected by upstream OCPD then no additional overcurrent protection is necessary.

If supplying a second building mains are often installed because you still need a main disconnect for that separate building. Six disconnect rule can apply though.

Some may want mains in nearly all panels for safety procedure reasons, but this is design issue not code driving that.
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And I see MLO MDPs with no OCPD at all on the customer side of the meter on residences all the time. Many of them have more than 6 breakers installed.
 
ggunn said:
And I see MLO MDPs with no OCPD at all on the customer side of the meter on residences all the time. Many of them have more than 6 breakers installed.
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But that's a different subject and not the case in the OP's scenario.

JAP>
 
karn said:
There is a main disconnect outside and . . . .
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There are two essential requirements, and this meets one of them. It might also meet the other, but you have not said enough for us to know. One requirement is that there must be a way to turn off power to the building. An MDP that has a main breaker achieves this requirement, but so too would a disconnect switch located upstream of the MDP. So you are good to go on this requirement. The other requirement is that the MDP must be protected against overcurrent. If the outside disconnect also has fuses, you will have achieved this requirement as well. If the outdoor item is an unfused disconnect, and given that the MDP has no main breaker, then you can only achieve this requirement if there are no more than six breakers on the MDP. Looking at your first photo, I see that this is not the case. So unless the disconnect has fuses, you do have a serious code violation. Reference NEC 408.36.

 
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