Owners Manual

20 © 2015 Sensata Technologies
Operation
Motor loads not starting – Some appliances, particularly those with
induction motors, require a much higher start-up surge than they do when
running. Pumps, freezers and refrigerators (compressors) are the most
common. The inverter may not be able to start some of these appliances
even though their rated current draw is within the inverter’s limits. If you
have the CMW1012 or CMW1512, and a motor-operated appliance refuses
to start, observe the VOLTS indicator on the digital display while you are
trying to start the appliance. If the display shows a battery drop below 11
volts while the inverter is trying to start the motor, this may explain why the
appliance won’t run. Make sure the length/diameter of the battery cables are
appropriate, battery connections are good, and the battery is fully charged.
If the cables are sized correctly, the connections are good, and the battery is
charged, you may need a larger battery bank (see Loads turning on and off).
Loads turning on and off – If a load starts but quickly turns off, then the
battery may not be able to deliver the necessary amperage to drive the load.
If the battery bank cannot deliver the necessary amperage to drive a heavy
load, the inverter will shut off due to low voltage (<10.5 VDC). The battery
voltage can then slowly rise back above the low voltage reconnect voltage
(11.8 VDC) causing the inverter to resume operation. As soon as the heavy
load draws the batteries down, this cycle will continue unless the load is
reduced or more batteries are added.
Loads too large – Although the CMW Series inverter can provide high
surge power up to two times the rated output power, some appliances may
still trigger the inverter shutdown/protection system. In these instances, a
higher power inverter may be required.
Running several loads at once – Sometimes the total surge requirement
of all the loads is higher than the CMW Series inverter can deliver. You may
want to turn them on individually to ensure that the inverter does not have
to deliver the starting current for all the loads at once.
3.3.2 Appliances and Run Time
CMW Series inverters can power a wide range of household appliances
including small motors, hair dryers, clocks, and other electrical devices. As
with any appliance using batteries for power, there is a certain length of
time that it can run—this is called “run time.” Table 3-2 below provides
estimates of power consumption and run time for various appliances using a
12V-120AH battery bank.
Table 3-2, Appliance Power Consumption and Run Time
Load Consumption Estimated Run Time
Cordless Phone 5W 180 hrs
Clock/Radio 8W 135 hrs
Table Lamp 40W/60W 27 hrs/18 hrs
Freezer (8.8 cu ft) 80W 15 hrs
20” LCD TV 100W 11.5 hrs
Refrigerator (18 cu ft) 120W 9 hrs
Sump Pump (1/2 hp) 350W 3 hrs
Microwave (mid-size) 1000W 49 min
Coffee Maker 1200W 37 min