Power Load Planning & Management
18
(b) For extremely hard to start loads such as air conditioners and air compressors, consult the equipment dealer to
determine maximum wattage
To calculate the running and starting wattage requirements for the devices you will be
powering, follow these steps:
1.
Make a list of all electrical devices you will be powering at the same time with the generator.
2.
List the greater of the running or starting wattage next to each device as obtained from the
devices’ nameplate or
Table 1
. If only the running wattage for a device with an electric
motor is known, the starting wattage can be estimated to be at least 3 times the running
wattage.
3.
Add the wattages for all devices on your list. This total must be lower than the continuous
output rating of your generator.
Example:
Device to be Powered
Greater of
Starting/Running Wattage
Light Bulbs (10 – 75 watt)
750 W
Refrigerator Freezer
1500 W
Microwave Oven 1000W
1000 W
Air Conditioner, Window (10,000 BTU)
2200 W
Sump pump (1/3 hp)
1300 W
Total
6750W
In this example, the generator must have a continuous output of at least 6750 watts in order to
power all of the devices simultaneously.
The overload indicator light 1 comes on when the total wattage exceeds the generators
capability. If that happens, proceed as follows:
1.
Turn off any connected electric devices and stop the generator.
2.
Reduce the total wattage of connected electric devices within the rated output.
3.
Check for blockages in the cool air intake (louver) and around the control unit. If any
blockages are found remove.
4.
After checking, restart the generator.
You can increase the number of devices your generator can power by staggering the load on the
generator. For example, you could alternately power your refrigerator and air conditioner for
limited periods of time -- powering only one of the devices at a time and never powering both at the
same time.
STAGGERING LOADS
