1、 Selection of measuring boxes
1) The measuring box can be made of two materials: "non-metal" and "metal".
2) Decentralized users should choose independent single meter boxes for electricity consumption.
3) If there are grounding conditions on site, a metal metering box should be selected. If there are no grounding conditions on site, a metal metering box should be selected.
Measurement boxes made of non-metallic materials should be used, and stainless steel measurement boxes can be used in coastal areas (humid, salt spray, and other corrosive and rusty environments).
2、 Selection of entrance line cross-section
1) BVV-2 is selected as the overhead and directly buried conductor for the incoming line × 6 copper core sheathed wire;
2) When laying wires in conduit and trunking, BVV-2 should be used × 10 copper core sheathed wire.
3、 Outlet method of measuring box
This typical design is based on the "Low Voltage Code of the State Grid of China" and includes four additional modules, namely the installation of corresponding metering boxes and their supporting inlet and outlet lines:
1) Single phase metering box with copper core sheath outlet (with protective tube or slot protection at the outlet).
2) Single-phase metering box, copper core sheathed outlet (outlet of residential vertical shaft cable tray)
3) Three-phase metering box, overhead insulated wire lead out (with protective tube or slot protection for the lead out).
4) Three-phase metering box, cable outlet (the outlet is protected by overhead or underground casing).
4、 Installation requirements for measuring boxes
1) The distance between the outdoor measuring box and the ground is 1.8-2m (referring to the distance between the bottom of the box and the ground).
2) The metal measuring box must be reliably grounded.
3) The center line of the highest observation window of the metering box in the vertical shaft of the community shall not be higher than 1.8m from the ground where it is installed. When installing walls, the distance between the bottom edge of the box and the ground at the installation site should not be less than 0.8m. When installed in underground buildings (such as garages, civil air defense projects, etc.), Should not be less than 1.0m
5、 Classic design scheme:
（1） Single-phase metering box, copper core sheathed wire outgoing line (outgoing line section is protected by protective tube or wire slot)
（2） Single-phase metering box, copper core sheathed wire outlet (vertical shaft cable tray outlet in the community)
（3） Three-phase metering box, overhead insulated wire outlet (the outlet section is protected by protective pipes or wire ducts)
（4） Three-phase metering box, cable outlet (the outlet section is protected by overhead or underground casing)
（5） Grounding device
1. Single-phase metering box, copper core sheathed wire outlet (the outlet section is protected by protective pipes or wire slots)
1) Metal multi position container metering box diagram (PVC casing protection for outgoing lines)
