Only two ungrounded conductors [hot] {any color in the rainbow except white, gray, green, or bare} and one neutral conductor [grounded] (white or gray) is normally required for a single phase service, however no equipment grounding conductor [green or bare] is required between the load side of the meter base and the main service panel. The neutral may be used as a dual purpose grounding and grounded or neutral if installed from the point of connection of that power company to and including the inside of the main service rated disconnect or distribution panel. NEC 250.142.A But anything that is installed on the load side of the main breaker must be with a separate neutral and a separate grounding conductor if that being installed uses a neutral or grounded leg. The neutrals and grounding conductors must be separated on any installation that receives its power on the load side of the main breaker or disconnect fuse.
The service equipment is that which contains the service disconnect (the first point to disconnect power from the utility, after the drop or lateral, and usually directly after the meter). Everything else is "load-side" equipment.
All grounding must comply with NEC tables 250.66 and NEC 250.122
- Three conductors with ground wire in conduit adequate for the load, weather head within 12” of service conductor leaving 18” drip loop.
- Meter base large enough for the load, and identify neutral and ground conductors.
- No copper and aluminum conductors under the same connection or lug must be approved connection.
- Use appropriate size switch to accommodate conductor, do not trim strands of to make it fit.
- 4 wire service when it leaves service disconnect under the meter, and complies with NEC tables 250.66 & 250.122
- NEC approved conduit from bottom of meter base or disconnect switch for a minimum of 12” below ground level. Ground all switch boxes, meter bases, all motors and all boxes of any type with a minimum of # 6 soft drawn copper (to pole ground where applicable) or NEC table 250.122.
- BCEC requires all Grounds and Ground Wire No Smaller Than # 6.
