Generator Safety & Operations

While CEMC is committed to providing safe and reliable power, outages do happen.  While most outages are restored quickly, weather and other factors can affect how quickly your power may be restored.  Generators are commonly used during these times to power crucial items such as heating/cooling, and refrigeration.  However, if improperly installed or operated, generators can be deadly to you, your neighbors and those working to restore your power. Taking precautions can keep you and your family safe from carbon monoxide poisoning and electrical shock.  They will also ensure that with proper installation, utility line workers will not be injured or killed while trying to restore your power during a power outage.


Safety

Always follow the instructions for operation from the generator manufacturer.  The installation and operation of the generator are critical to using the generator to supply your power needs safely.  Failure to heed these precautions could result in serious injury or death to an unsuspecting co-op lineman, a neighbor or family member.

Generators should never be operating in enclosed spaces unless designed by the manufacturer with proper ventilation in place.  This could lead to carbon monoxide (CO) poisoning which is often fatal.  Also when operating a generator outside, be sure to place it a minimum of 10 feet away from operable windows and doors.

Portable generators are recommended for a few hours of operation at a time. This will conserve fuel for the generator that may not be readily available in weather impacted conditions. Never leave a generator running when the home is unoccupied. Remember that in emergency situations, the generator is meant to power appliances as little as necessary until power is restored.


About Generators

Steps to Proper Installation and Safety
Consult and discuss your purchase options with a reliable vendor to meet your needs and situation Properly size the generator to run your essential appliances without overload.
Have a qualified electrician install a transfer switch. The transfer switch breaks the path of electricity between the powerlines and your main electrical panel.  This is the best way to protect you, your neighbors, and utility crews from “back feed”. Back Feed occurs when an improperly connected generator begins feeding electricity through the utility transformers and onto the power lines.  The lower voltage from the generator can be increased to thousands of volts by the transformers and this can seriously injure or kill anyone near power lines, especially crews working to restore power. 
Never plug a portable generator into a wall outlet or connect to a home’s wiring or breaker panel.  Back Feed can occur here also. The main breaker in your home's electrical panel may not sufficiently break the path of power to the power lines.
Do not overload the generator.  A portable generator should only be used when necessary, and only to power essential equipment or appliances.  Overload can lead to damage to the generator or appliances and create other hazards
Use a ground fault interrupter (GFCI) to help prevent electrocutions and electrical shock injuries Should the electrical path be shorted, the GFCI will interrupt the flow of power at the plug before it reaches other circuits within the home.
Use proper extension cords.  Use only safety tested, heavy duty outdoor listed cords to connect appliances Insufficient extension cords could become overloading and lead to risks such as fire or electrocution
Shut down generators safely.  Before shutting down a generator, turn off and unplug all appliances and equipment being powered by the generator. Follow manufacturer instructions for proper shut down procedure.  Disconnect all electrical connections.

 

Portable generators are designed to supply auxiliary power to specific appliances/equipment using extension cords directly connected to the generator. Most portable generators are mobile and temporarily connected in the event of emergencies.    

Choosing the size of the generator (watts) begins with choosing which appliances/equipment you want powered during emergency situations. The wattage of portable generators typically ranges 1,500 (1.5 kW) to 15,000 (15kW) watts. Below is a chart of common power consumption of appliances in the typical home.  These figures are estimates, and the homeowner should verify the wattage of appliances in the home before making a final purchase.

The extension cords used with a portable generator also should be properly sized to handle the electrical requirements of the appliance.

A double-throw transfer switch can be installed by a licensed electrician in the home’s wiring distribution to permanently connect a portable generator to a specific electrical circuit (water pump, HVAC, etc.) This will allow for easy connection of the generator, but most importantly, will isolate the circuits from the utility grid when in use to ensure safety for line workers and other homes connected.

Stand-by generators are permanently wired to the home’s electrical system. Most are designed to automatically operate as power interruption is detected, and shut down as power is restored. These are commonly fueled by propane, natural gas, diesel or gasoline and should be installed by a licensed electrician. For residential units, the wattage ranges from about 5,000 watts (5kW) to 25,000 watts (25kW). 

The start-up of these motor/compressor loads must be considered when sizing a generator for your needs. Appliances/equipment with a motor or compressor will draw more current during start-up than during normal run time.

Permanently installed standby generators use a transfer switch to connect certain electrical circuits within a home to the generator. A licensed electrician should install the transfer switch, as the installation is vital to safe operation of the generator. 

 

Transfer switches are rated at 30 amperes, 50 amperes and larger. A 7,500 watt (7.5kW) generator will accommodate a 30 amperes transfer switch, while a 15,000 watt (15kW) generator will accommodate a 50 amperes switch. There are transfer switches available up to 200 amperes.

A meter based transfer switch allows operation of any circuits in the home up to the capacity of the switch and generator