electrical junction box with terminal blocks

Just as each dock at the port is intended for a different line of shipment, each terminal within a junction box is intended for a different electrical connection. You can think of each terminal within a junction box as a dock within a shipping port. If you need to remove the insulation from the tips of the wires, you can use a set of wire strippers to strip the insulation off before connecting the wire to the terminal. Make sure to use a good insulation resistance tester if you need to measure the insulation resistance. You often have multiple terminals within the same junction box, with each terminal serving as a connection point for two different wires. Junction Box TerminalsĪ terminal is a point within the junction box where two wires are connected together. This overrating acts as a safety buffer – preventing human error in rating calculations or unexpected fault conditions from causing harm. It’s always a good idea to overrate your electrical junction boxes rather than underrate them. This rating is used to determine if a junction box can handle the maximum fault current of your intended circuit. This protection rating is generally given in amps. Lastly, you have the electrical protection of a junction box. Manufacturer will usually give details of maximum depth and/or pressure conditions)

IP68 junction boxes – IP rated as “dust tight” and protected against complete, continuous submersion in water (suitable for continuous submersion at depths below 1m.

IP67 junction boxes – IP rated as “dust tight” and protected powerful jets of water or against heavy seas (up to 1m depth of submersion).

IP65 junction boxes – IP rated as “dust tight” and protected against water projected from a nozzle.

The exact level of protection will depend on the IP rating. There are varying levels of protection – for example, dust or water resistant junction boxes, dust tight junction boxes, watertight junction boxes, and submersible junction boxes. ‘ Ingress of foreign objects’ is just a fancy way of saying ‘ what can and can’t enter into’ the junction box. The IP rating describes the degree to which a junction box provides protection against the ingress of foreign objects, dust, and moisture. This is commonly known as an ‘ IP rating’. The rating also indicates how well the junction box is protected against oil, coolants, and corrosives.Īnother popular rating system is the Ingress Protection (IP) or International Protection rating system. The NEMA rating will tell you whether an electrical junction box is suitable for use in hazardous or non-hazardous locations, and indoor or outdoor use. The NEMA ratings outline the environmental conditions that a electrical junction box can withstand, such as whether the junction box can protect against dust, light, wind, snow, and other weather conditions.įor a weatherproof electrical junction box, you want at least NEMA Type 3 (Type 3X/3RX/3SX if you also need protection against corrosion). The National Electrical Manufacturers Association (NEMA) defines standards used in North America for various grades of electrical enclosures (i.e.

The material the junction box is made from.

How the wires are connected within the junction box (the type and number of terminals).

The protection rating of the junction box.

These are the four main factors you need to consider when choosing a electrical junction box: The right junction box for you will depend on what you need it for.ĭo you need a waterproof junction box? Is it an outdoor or indoor junction box? Is it a 4 or 8 terminal junction box? The list of questions goes on. There are many different types of electrical junction boxes, and they are made of some form of metal or plastic. An electrician’s life would be a lot harder if it weren’t for junction boxes. This type of organized arrangement makes doing any kind of electrical work a whole lot easier (just like using the right set of electricians tools). Larger junction boxes can also contain whole house surge protectors. Each junction box in a building typically indicates a different section of wiring within the overall floor plan.

They also help simplify all the electrical wiring within a building. When properly covered, they stop fires that start within the junction box from spreading. They stop unwanted objects – like water, rats, and your hands – from coming into contact with live wires. In short: junction boxes serve as a protective casing for a section of wires, similar to a feeder pillar. It prevents fires within the junction box from spreading (when properly covered).It organizes the electrical floor plan into units.It prevents small critters ( rats) from chewing on your wires.

It protects your wires from dust and dampness.It protects people from coming into contact with live wires.A junction box serves a variety of purposes:

Electrical junction box with terminal blocks