Anatomy of an Emergency Power System


In the face of natural disaster, power outages are inevitable. Preparation is key to limiting damage and the loss of property and life. When storm warnings are issued people begin stocking up on food, water, gas, batteries, and other supplies to get them through. Some people assume that stores and stations will remain operational when they need supplies. For the most part, these facilities need power to be able to provide services and loss of electricity can be paralyzing. This is where emergency power systems come into play. These systems are a lifeline to those in need. During a natural disaster, or any other emergency situation, temporary power systems can supply constant reliable power when the utility supply has become intermittent, insufficient, or completely unavailable. Even when the storm passes, receiving reliable utility power can still be a challenge. Emergency power systems can aid in the relief and rebuilding of disaster areas long after the storm has gone.

When and Where it is Required

It is important to understand when these systems are not only needed, but required by law. These regulations vary by state and in some cases considered unnecessary. States that are at low risk for natural disaster may not even have laws in place to require these provisions. States like Florida, however, have clear requirements for fuel stations along evacuation routes to be outfitted with the proper equipment for emergency power. These regulations are not limited to service stations. In some states laws will require these backup/emergency power systems for healthcare facilities, frozen food storage, or even explosive goods containment. Owners of these types of facilities should familiarize themselves with the laws and requirements applicable to them based on their industry and state.

Components of a System

Components of an emergency power system can vary based on whether the facility has a permanent backup generator or provisions for a portable/temporary generator. For this article we will focus on the latter. These systems commonly consist of a portable generator, a connection box, and a transfer switch.

1. Portable Generator

Portable generations vary in size and output based on the application. Typically, these generators are either truck or trailer-mounted for easy transport. Cables run from the generator to the generator connection box to energize the system.

2. Generator Connection Box

Connection boxes are the critical link between the generator and the transfer switch. Depending on their size generator connection box can be pad or wall mountable. The load side of the docking station is hard-wired to the transfer switch via conduit. On the line side, connection boxes are commonly outfitted with color-coded quick connections called camlocks. These quick-style inputs make it fast and easy for authorized personnel to connect the generator. These stations eliminate the need for time consuming hard-wire connections between the generator and transfer switch.

3. Transfer Switch

A transfer switch is a piece of equipment that connects a load to one of two power sources. In emergency power situations, these sources are typically utility power and temporary power (generators). Transfer switches are hard-wired to these sources on the line side as well as hard-wired to the building’s main panel board on the load side. There are many types of transfer switches including manual and automatic configurations. Transfer switches should have break-before-make operating mechanisms or interlocks to prevent cross-connecting power sources.


Generator cables are also a key component to the safety, ease of use, and quick set-up times of these systems. These cables are typically Type W with camlock (twist lock) connectors on each end. The single-conductor cables should also be flexible and abrasion resistant.


Emergency power systems play an important role in minimizing the effects of natural disasters and other emergency situations. These systems need to be planed out according to the needs of each individual facility. Choosing the right transfer switch and docking station is the first step in establishing a backup/emergency power system and preparing for the next power outage.