An electrical service assembly for mounting in a building structure wall includes an entrance panel housing, a power meter base and a connecting system connecting the power meter base to the entrance panel housing. The connecting system includes a body having a first surface abutting the power meter base, a second surface abutting the entrance panel housing and a thickness between the first surface and the second surface whereby the body spaces the power meter base from the entrance panel housing. The connecting system further includes a clamping mechanism, such as a set of fasteners, clamping the power meter base, the entrance panel housing and the body together in an assembly configuration where a wiring through-hole formed in the entrance panel housing is in register with a wiring through-hole formed in the power meter base.