CRITERIA NEEDED FOR THIS INTERCONNECTION

The example to the right shows what your setup might look like for this type of interconnection. This will be most common on town homes. Depicted is a main disconnect (MSP) attached to the meter on the exterior of the building. The sub panel is on the interior of the home over 10 feet away from the meter with no main breaker. not depicted is the labeling indicating that it will not accept a main breaker.

This interconnection has the following requirements that need to be met before it can be considered:

1. The sub panel is feeding directly from a main disconnect on the exterior of the home.

2. load side breaker interconnection in the MSP is not possible or otherwise not preferred.

   • In the case this is a main-disconnect type enclosure with no other load side bus attached. It is direct feeding the sub panel.

3. There are at least 3 inches of feeder length to tap to from the MSP.

4. There must be no code violations present in and around the MSP. 

   • If there is a plan in place to resolve code violations, then  you can consider this condition met.

5. There must be sufficient available backfeed for the amount of PV we will be landing in this load center.

An option for protecting this sub panel is to redirect the feeders onto a new sub panel that will house the main disconnect.

1. The existing feeders were removed from the bottom lugs of the MSP.

2. New feeders were ran from the bottom lugs of the MSP to feed the new sub panel mounted beside the MSP.

3. The new sub is installed with a main breaker positioned at the top with lugs at the bottom.

   1. feeders were extended and spliced to the existing feeders that feed the interior sub panel.

We have now placed a main disconnect between the PV and the main lugs of the existing sub panel.