[measure thrice]

Please let me clarify "INSIDE"
My meter is mounted on the back of the house with the underground utility run coming to the surface below the meter. My panel in mounted on the other side of the exterior wall (in a hallway).

There is a direct connection via an approximately one inch ID fitting between the meter box and my panel box. In the winter so much cold air comes through this opening that a sixteenth inch of ice can form on the panel door.

I'm wondering if there is a recommended way to seal this gap INSIDE the conduit. The one inch opening has only four wires coming through.

There are many products for sealing gaps around the conduit, but are there any that are safe to use inside.

There is a "Great Stuff" Fireblock form for sealing around electrical runs. I'm not sure if this would have any long term effect on the insulation.

Thank you in advance for any suggestions.

 

[InPhase277]

Please let me clarify "INSIDE"
My meter is mounted on the back of the house with the underground utility run coming to the surface below the meter. My panel in mounted on the other side of the exterior wall (in a hallway).

There is a direct connection via an approximately one inch ID fitting between the meter box and my panel box. In the winter so much cold air comes through this opening that a sixteenth inch of ice can form on the panel door.

I'm wondering if there is a recommended way to seal this gap INSIDE the conduit. The one inch opening has only four wires coming through.

There are many products for sealing gaps around the conduit, but are there any that are safe to use inside.

There is a "Great Stuff" Fireblock form for sealing around electrical runs. I'm not sure if this would have any long term effect on the insulation.

Thank you in advance for any suggestions.

I doubt a layer of Great Stuff would be a problem, since it sets so quickly. This would probably be the best way to go. But, don't use too much, because we don't want it so expand so much that it actually moves the conductors and forces them against the conduit walls.

Some duct seal putty would also work.