Energy Demand Management Tech Tips
Energy Demand Control Information
Energy Sentry offers a wide range of information on demand controllers, demand control theory, and tips for controlling electric loads.
General Installation Warning Notice |
Energy Sentry Demand Management System installation is required to be performed by a licensed and duly-qualified electrician. |
Demand Control Theory |
Wally ran a hamburger stand that had 20 seats. Every day at noon sharp, 60 customers arrived for lunch. Wally had a peak demand for hamburgers at noon. |
Load Control Strategy |
The way the demand controller controls loads is called the load control strategy. In one sentence, it is the definition of each load’s importance in relation to all other loads being controlled by the system. |
Tips for Controlling Common Electric Loads
Control of Electric Clothes Dryers |
Most electric clothes dryers used in homes today have 5500-watt , 240-volt heating coils with a 120-volt fractional horsepower motor. It is very difficult to operate an all-electric home below 8 kW if the dryer is not controlled by a demand controller. |
Control of Electric Water Heaters |
Most residential electric water heaters used in homes today have two 4500-watt, 240-volt heating elements. These elements are interlocked by the water heater’s internal thermostat so that only one element can come on at a time. |
Control of |
Most resistive heating circuits are fed from a 20A, 240V breaker, with different circuits for different areas of the house. While these breakers may be labeled by location, it is very important to verify this so that they can be connected to the controller in the proper priority. |
Control of Heat Pumps |
Two separate loads in heat pumps usually must be controlled: The compressor and the backup (auxiliary) heat. Generally, the compressor is controlled by breaking the low-voltage signal from the thermostat, usually the Yellow (Y) wire. |
Control of Electric Furnaces |
Most residential furnaces have between 10 kW and 25 kW of resistance heat installed. Usually the total wattage is divided into 5 kW elements, staged by timing relays controlled by a “sequencer.” |
Control of Electric Boilers |
Electric boilers contain several 5 kW elements that are usually staged to turn on and off with timed sequencers. You must break each element individually with a separate relay with line voltage control in order to control the elements. |
Control of Air Conditioners |
Air conditioning compressors are easiest to control by breaking the low-voltage signal from the thermostat to the compressor relay. This is normally the yellow wire (“Y” or “Y1”). |
Control of |
Control the Compressor contactor by breaking the low-voltage signal from the thermostat, usually the YELLOW wire. Be sure to program a minimum OFF-TIME on the relay of at least 5 minutes to prevent short cycling of the compressor, and a minimum ON-TIME of 6 to 9 minutes for desired comfort level. |