What is an Electrical Service Disconnect and why is it Important?

2019 Feb 26
Posted in: Electrical

Unlike other hazards, electricity can be a lethal but invisible threat when things go wrong on your property. Not all electrical damage or malfunctions will manifest as an arcing wire with all the noise and visuals to warn of danger. A failure or problem can result in surfaces or objects becoming energized and potentially fatal to come in contact with. In the event you experience an emergency or just need to conduct maintenance, repairs or upgrades to your home, an electrical service disconnect can keep everyone safe.

Where is the electrical disconnect?

All electricity from the public utility or power company flowing into a home can typically be stopped at the utility meter and beyond that, isolated at the electrical disconnect. It’s very important to note that the electricity coming from your power company to the utility meter box for your property is at an extremely dangerous voltage (usually 240 volts) and cannot be shut off by the homeowner. These lines from the power company to the residential utility meter are always live unless the electricity has been shut off by the serving utility.

Depending on the age of your home, the electrical disconnect may be the main circuit breaker within the home’s main electrical service panel or it may consist of a breaker switch found in its own box on the exterior of the home or property. Some homes will have both an external switch housed in an exterior box and an electrical service panel within the home, such as in the basement, utility room, or kitchen.

Why is a service disconnect important?

A service disconnect is a means for shutting the power off between the facilities of the service utility (your power company) and the premise wiring (your home or property’s electrical system). The disconnect is important because it acts to protect workers repairing, maintaining or making changes to a home’s electrical system by disconnecting power to and de-energizing the property’s electrical systems. In the event of an emergency such as a fire or flood, the disconnect can be used to help lessen the risk of rescue personnel being injured or electrocuted. In a damaged or flooded home these workers or first responders may face dangerous conditions if the water, rubble, or debris has been energized.

First-responders are at risk when coming to a home where an electrical system may be compromised, as there are often few warning signs of danger. Many public electrical companies monitor their systems remotely and it’s not safe to assume that because the power went out somewhere else further down the line that the power will not reconnect, as most utilities will attempt to restore power delivery to a grid and may not be aware of circumstances such as a fire or damage to a home or other structure that has compromised the safety of its electrical system.

Therefore it is critical for first responders and repair personnel to be able to reliably disconnect the flow of electricity to a structure. If an electrical panel becomes energized after fire damage it could energize other parts of the home that may not otherwise be considered dangerous such as an electrical system that is grounded to the water system.

How to stay code-compliant

If the fire or issue originated from an electrical malfunction, shutting off the power can also help contain further damage to the home until appropriate code-compliant repairs can be made to rectify issues in the electrical system that caused the problem.

An electrical service disconnect should be at a readily accessible, easy-to-find location outside the structure, or adjacent to the main electrical panel. It cannot be installed in a bathroom. The service disconnect must be clearly and permanently labeled. If there is more than one service for a property, the location for both should be clearly marked at the location of each service disconnect. If the electrical service disconnect is located outside, it should be able to withstand environmental conditions.

There are substantial code and safety considerations involved with installation, maintenance and repair of an electrical service disconnect. Additionally, all service conductors going into your utility meter box will be live coming from the utility provider or power company and cannot be shut off by the property owner. Therefore it’s important to always hire a licensed electrician for any work involving an electrical service disconnect. Give George Brazil a call at any time!