If your home, health or business cannot be without electrical power for any length of time, standby generators are a good idea for those few times power is interrupted. But there are some special safety precautions you must take for your home or business, if you switch over to the alternate power source.
Transfer switches, usually at the meter, disconnect power from the existing electric source (PREMA) and switch to the standby generator. The switch prevents power from feeding back into the PREMA system, getting stepped up at the transformer and causing major damage and/or lost lives back up the line.
When power is out on the PREMA system, our lineman will be out working on the lines to restore power. Safety demands that lines be de-energized while working on them. They are also grounded for additional assurance. PREMA does work on lines while they are energized but under different circumstances. If a 240-volt surge comes back from a generator, it can be stepped up to full line voltage at the transformer and could travel through the lines where PREMA men are working.
The problem is not unique to the PREMA system. In fact, the National Electrical Code requires transfer equipment. Section 230-83 says transfer equipment, including transfer switches shall operate such that all ungrounded conductors of one source of supply are disconnected before any ungrounded conductors of the second source are connected.
Suitable transfer equipment, including transfer switches, is required to ensure that successful shifting of loads from normal power to emergency power will occur without back feeding into utility power lines. National electrical code is developed by the National Fire Protection Association.
PREMA will install transfer switches on a residential service for a fee of up to $450.00. This is less than half the cost of the switch and installation. For any non-residential services, the cost to the consumer will be assessed at PREMA's cost of the switch and installation.
If you have any questions about safe use of generators, please contact PREMA at 308-762-1311 for more information.
Effective Date 01/01/18