A bell box is a weatherproof aluminum electrical enclosure that protects outdoor wiring connections from rain and moisture.
For the full breakdown, see our best Bell Box Electrical guide.
A gray metal box bolted to the side of a house, with conduit snaking into its threaded hubs, is usually a bell box electrical enclosure. The name comes from Bell, a Hubbell brand that builds weatherproof boxes for outdoor wiring — not from anything that rings.
Outside the US, “bell box” can mean an alarm sounder or chime unit, so context matters. In American electrical work, it almost always means a weatherproof enclosure for branch-circuit wiring in wet, damp, or dry locations. Weatherproof here means sealed against rain and splashing water — these are surface-mount enclosures, not submersible boxes.
What Does a Bell Box Do?
A Bell box protects electrical connections in places where weather can reach them — exterior walls, patios, and other moisture-prone spots. Hubbell’s Bell product line is built for exactly this job: keeping rain, snow, and humidity away from wiring so corrosion and shorts don’t get a foothold.
The typical unit is die-cast aluminum with threaded openings for conduit. You mount the box to a flat surface, run conduit or cable into a hub or fitting, and seat the gaskets properly so the weatherproof seal holds. Some models suit new work, others old work, and several ship with closure plugs for unused openings plus self-threading ground screws for grounding the metal box.
In practice, you’ll see these boxes on exterior receptacles that power holiday lights, junction boxes for landscape lighting, and surface-mount housings for sprinkler timers and pool equipment. The difference from a standard indoor box is the seal: weatherproof covers, gaskets, and threaded hubs keep water out where an open knockout would let it pour in. The corrosion-resistant aluminum body is why they keep working outdoors for decades.
Bell Box Specs: Gangs, Hubs, and Capacity
Bell boxes come in