I feel confident in putting the mat inside the electrical panel. The outside panel is visible from my gate, set back about 35’ from the street. However, if I put the mat on top of the panel door, visible to anyone near my gate, they could just take it. I feel safer having it nearly enclosed by the panel door (which doesn’t seal closed after 40 years), magnetically clamped to a wall portion of the panel, draped across the breakers and sticking out about 1/4" on the other side of the panel (if I cut off 1/2" X 8", it would fit perfectly and I could close the panel door).
In my music room, I have a dedicated subpanel. I put the mat magnectically attached across the inside of it and across the breakers.
I don’t see how any heat build-up will ever occur in the breaker boxes. The exterior panel has been serviced recently by an electrician. The interior box is 25 years old.
If Tim says I’m better off putting the subpanel one outside the box, I’ll do it but I really don’t feel safe leaving the mat exposed to view on the outside panel. Also, if I put the mat magnetically attached to the inside of the outside panel door still sticking out slightly, will it be as effective?