Circuits in an AL distribution box are assigned reference numbers based on the electrical identification number of the box, with sequential numbering for each circuit and associated junction boxes.

Circuit Numbering in AL Distribution Boxes

Each AL distribution box, such as the HWB60-AL series, is treated as a main power distribution module. Every circuit fed from the box is assigned a Power Circuit (PC) reference number, which is prefixed by the electrical identification number of the distribution box. This ensures that each circuit can be uniquely identified for documentation, labeling, and maintenance purposes .

Numbering Conventions

1. Sequential Numbering: Circuits are numbered sequentially, typically starting from the incomer (main input) and progressing through the subsidiary circuits in order of electrical importance, such as bus sections, transformer feeders, and connected equipment .
2. Junction Boxes: If a circuit has multiple junction boxes, each box is labeled by prefixing the PC reference number with CJB- (control junction box) or PJB- (power junction box). Additional boxes in the same circuit are suffixed with a slash and a sequential number (e.g., PJB-101/2), .
3. Special Systems: For systems like fire alarms or trace heating, junction boxes are prefixed with FJB- or HJB-, followed by the circuit or zone number .
4. Labeling: The PC reference number is displayed on the front of the distribution box or compartment, and also appears on schematics and interconnection diagrams for clarity .

Practical Example

For an AL distribution box with an electrical ID AL01:

• Main incomer circuit: AL01-M101
• First subsidiary circuit: AL01-C102
• Second junction box in the same circuit: AL01-C102/2
• Fire alarm junction box in zone 3: FJB-3 This system ensures consistent identification across all circuits and associated components, facilitating maintenance, troubleshooting, and compliance with electrical documentation standards .

Summary

In summary, AL distribution box circuits are numbered using a combination of the box's electrical ID and sequential PC reference numbers, with additional prefixes and suffixes for junction boxes and special systems. This standardized approach allows clear labeling, easy reference in schematics, and safe management of electrical circuits.