sub panel disconnect

[c.dinardi]

I installed a 100amp sub panel in a detached garage that was converted into a living space. The sub panel is lug, feed from the houses on a 100amp breaker from the main panel. the inspector is telling me that i need to put a 100amp breaker in the sub to serve as the disconnect means, or install a new panel with a main disconnect. Doesn't the 100amp breaker from the main serve this purpose. I cant find any thing in the N.E.C. that states I have to have a main disconnect in my sub panel. Any help would be appreciated

 

[selectelectric]

Detached Garage

Detached Garage

No I don't have my book right with me but if the garage is detached you do treat it as a separate service it requires a main disconnecting means and its own bonding grid

 

[Dennis Alwon]

I installed a 100amp sub panel in a detached garage that was converted into a living space. The sub panel is lug, feed from the houses on a 100amp breaker from the main panel. the inspector is telling me that i need to put a 100amp breaker in the sub to serve as the disconnect means, or install a new panel with a main disconnect. Doesn't the 100amp breaker from the main serve this purpose. I cant find any thing in the N.E.C. that states I have to have a main disconnect in my sub panel. Any help would be appreciated

Look at section 225.32. The inspector is correct to a point. If you have 6 circuits or less then the 6 circuits can be considered the disco for the building (section 225.33). I personally would probably put in a 100 main breaker kit.

 

[augie47]

You might want to be sure to look at Art 225 & Art 408 with emphasis as to what Code cycle you are on. 08 made some significant changes in panels.

 

[c.dinardi]

i did a little more digging and came up with these codes.

NEC 225.31 States that means shall be provided for disconnecting all ungrounded conductors (hots) that supply or pass through a building or structure.

NEC 225.32 States that the disconnecting means shall be located either inside or outside the structure served or where the conductors pass through the building and it shall be readily accessible located nearest the point of entrance of the conductors.

So 225.31 is telling you that you are required to have a disconnect and then 225.32 is telling you that this disconnect has to be either inside or outside the building and where the wires pass through the building - so they could not located on another structure.

 

[mcclary's electrical]

I installed a 100amp sub panel in a detached garage that was converted into a living space. The sub panel is lug, feed from the houses on a 100amp breaker from the main panel. the inspector is telling me that i need to put a 100amp breaker in the sub to serve as the disconnect means, or install a new panel with a main disconnect. Doesn't the 100amp breaker from the main serve this purpose. I cant find any thing in the N.E.C. that states I have to have a main disconnect in my sub panel. Any help would be appreciated

If you have less than six, you're good, more than six, you need a main.

 

[don_resqcapt19]

Before using the "six disconnect rule" you need to look close at the panel label. The disconnect for a second building is required to be suitable for use as a service disconnect. The labeling in some panels tells you that the panel is suitable for use as service equipment only when a main breaker is installed in the panel.

 

[Dennis Alwon]

Before using the "six disconnect rule" you need to look close at the panel label. The disconnect for a second building is required to be suitable for use as a service disconnect. The labeling in some panels tells you that the panel is suitable for use as service equipment only when a main breaker is installed in the panel.

This is true but I have not seen a panel in many years that wasn't suitable for service disco. I guess this panel could be one of them so that is good advice.

I wonder what the difference is between a panel that is suitable and one that is not. Probably it was just never tested for that purpose.

 

[charlie b]

OK. You figured out that since this is a separate building, it needs a disconnecting means. You figured out that the breaker in the house panel will not count. But that doesn?t mean that the garage panel must have a main breaker. One way to meet the requirement is by placing an enclosed disconnect (or breaker) on the outside wall of the garage, or on the wall just inside. But do keep in mind the rules that govern the separation of neutrals and grounds, that govern the connection of equipment grounding conductors for garage circuits, and that require the garage to have its own grounding electrode system.