Appleton Explosion Proof Electrical Box: Types & Uses

An explosion proof electrical box is capable of restraining any explosion originating within its enclosure. It can also prevent any spark within it from igniting the gasses, dust, vapors, and fibers present in the surrounding air.

So, the term ‘explosion proof,’ when applied to electrical boxes, doesn’t mean that it can withstand an external explosion. Instead, the term indicates that a box can contain an internal explosion so that it does not detonate a bigger blast and prevent an inner spark from triggering an accident.

There are explosion proof electrical junction boxes, conduit outlet boxes, electrical enclosures, and other types.

Appleton Explosion Proof Boxes


Many manufacturers produce high-grade explosion proof boxes that are specially designed for applications where flammable fibers, harmful vapors, dangerous liquids, hazardous gasses, combustible dust, etc. can exist during the time of operation. However, Appleton boxes are one of the most popular and widely used in various industries including petrochemical plants, oil refineries, mining facilities, waste water treatment plants, and more.

Let’s take a look at the type of those boxes and their applications:

CPU Boxes

Such an explosion proof electrical box offers flexibility in applications with four threaded hubs and three close-up plugs. They are used in classified hazardous locations, and rough environments for wiring, changing the direction of conduit runs, helping in wire pulling, connecting conduit lengths, and allowing access for maintenance.

GR and GRF Boxes

GRF boxes come with an integral mounting flange while the GR types have ten hub arrangements. They are corrosion resistant and dust-ignition proof along with being immune to an internal explosion.

These boxes are ideal for both indoor and outdoor uses in hazardous environments.

GRH Boxes

These boxes are specially designed for applying in a broad range of risky and perilous industrial environments. They comply with a variety of industrial area requirements.

GRG Boxes

This explosion proof electrical box type is flexible for various application because they are available in different sizes and hub configurations. Their compact sizes make them ideal for installation in tight spaces.

GRGS Boxes

These boxes feature five threaded hubs and three close-up plugs that make the installation process easier. Like the GRG boxes, they are also compact and thereby ideal for tight spaces. Additionally, you can use them for mounting lighting fixture.

GRSS Boxes

They comply with a broad range of classified area requirements. These boxes are easy to install for various applications because they have multiple hubs for flexibility.

GRU Boxes

They are corrosion resistant, dust-ignition proof, and explosion proof. So, you can use them in an array of industrial applications such as general purpose wiring, connecting conduit lengths, changing conduit run’s direction, and more. They feature union hubs for ease of installation.

There more explosion proof electrical box types produced by Appleton. You have to pick up the right category based on the requirements of the environment where you’ll use them.