1. Common LEB terminal box sizes (4 models)
| Model | Terminals | Enclosure Size (mm) | Installation | Application |
|---|---|---|---|---|
| LEB-4 | 4-position | 250×180×80 | Flush mount | Small bathroom |
| LEB-6 | 6-position | 300×200×80 | Flush mount | Standard bathroom |
| LEB-8 | 8-way | 350×250×80 | Flush / surface mount | Large bathroom / shower area |
| MEB-12 | 12-way | 400×300×100 | Surface mount | Building entrance |
2. How to determine terminal count (by number of items connected)
LEB terminal count = number of items connected + 1 (PE incoming) + 1 (bonded to MEB). Typical bathroom: 1 PE incoming + 1 cold water pipe + 1 hot water pipe + 1 heating pipe + 1 rebar + 1 MEB bond = 6 terminals. Allow 1–2 spare terminals and choose LEB-6 or LEB-8.
3. Mounting height (GB 50303)
GB 50303: LEB terminal boxes are flush-mounted in the bathroom wall, with the bottom edge 0.3–0.5mabove floor level. Avoid a location directly sprayed by the shower; typically install behind the door or under the washbasin.Must not be installed inside a suspended ceiling— it makes servicing difficult.
4. Enclosure materials (3 Types)
| Material | IP rating | Application | Price |
|---|---|---|---|
| Painted steel | IP30 | Indoor, dry | Low |
| Stainless steel 304 | IP54 | Damp environments | Medium |
| Flame-retardant ABS | IP44 | Indoor flush mount | Low |
5. LEB Selection Reference (by location)
| Location | Model | Terminals | Conductor cross-section |
|---|---|---|---|
| Standard bathroom | LEB-6 | 6-position | 6mm² |
| Large bathroom / shower area | LEB-8 | 8-way | 6mm² |
| Swimming pool | LEB-8 | 8-way | 10mm² |
| Hospital operating room | LEB-8 + MEB | 8+12 positions | 10–16mm² |
FAQ FAQ
What is the standard size of an LEB terminal box?
Commonly 250×180×80mm (4 positions) to 350×250×80mm (8 positions); the number of terminals is determined by the number of items to be bonded.
How do you calculate the number of LEB terminals?
Number of bonded items + 1 (PE incoming) + 1 (MEB link) + 1–2 spare. A typical bathroom uses 6 positions.
What is the installation height for an LEB?
Bottom edge above floor 0.3–0.5m, flush-mounted in the bathroom wall, away from direct water spray.
What special requirements apply to an LEB for a swimming pool?
More terminals (≥ 8 positions), conductor cross-section ≥ 10mm², enclosure ingress protection ≥ IP54, stainless steel enclosure.
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