Guide

Specifying a Distribution Box for the Installation Site

Metal or plastic, indoor or outdoor, surface or flush. The enclosure decision is usually made last and causes the most site problems.

Match the Enclosure to the Environment

An indoor consumer unit in a dry hallway and a cabinet on a farm wall are not the same specification. The range covers plastic PZ30 style boards for indoor final circuit distribution, JXF metal boxes for industrial and plant room positions, and IP65 rated waterproof boxes for outdoor and wash down locations.

Water proof distribution box HT Type in ABS plastic, front view with sealed lid — Water Proof Distribution Box

Count the Ways Before Choosing the Size

Ways are counted in DIN modules, not circuits. A single pole MCB is one module, a four pole smart breaker takes four, and an AFDD or RCBO usually takes two. Boards fill up faster once smart and arc fault devices are added, so it pays to count modules at the design stage.

Plastic MCB distribution box with 2-4 ways, front view showing push-button switch and circuit chart — Plastic MCB Distribution Box

Ingress Protection in Plain Terms

IP65 means dust tight and protected against water jets. That is the specification for an outdoor cabinet or a pump house. Indoor boards do not need it and are cheaper without it.

JXF power distribution box in front view showing welded construction and surface finish — JXF power distribution box

Metal or Plastic

Metal enclosures suit plant rooms, workshops and positions where impact is likely. Plastic boards are lighter, insulating and normal for domestic and light commercial final circuit distribution.

Leave Room for the Smart Upgrade

Buyers who expect to retrofit smart breakers later should specify spare modules now. A four pole smart device needs the same space as four single pole devices, and a full board is the most common obstacle to a retrofit.