158 Service entrance equipment weather head overhead wires service mast meter base and meter on exterior 3-wire 120-240V service height above grade in accordance with electrical code requirements grounding wire main breaker distribution panel 12.7 mm (1⁄2 in.) support panel fixed to wall Note: Capacity 100 to 200 amps. The service wires are brought to the main breaker located in the basement through a rigid conduit. The main breaker and distribution panel containing branch circuit protection (breakers or fuses) are mounted on a plywood or OSB back-up panel. floor joists water supply pipe fixed to back-up strip combination service entrance panel water meter ground wire clamped below shut-off valve finished basement floor Note: Service equipment must be grounded. Note: Ground wire from main entrance panel must be clamped to the water service entrance pipe below shut-off valve as shown (metallic pipe only).