Calculating size of an ac load, Calculating size of an ac load –4 – Xantrex Technology RM1012 User Manual

Page 16

Advertising
background image

Operation

2–4

intersection of the time and temperature will indicate approximately the
output power of the unit. For example, between – 40 °F (– 40 °C) and
77 °F (25 °C), you will get 3000 watts for approximately two minutes or
2500 watts for 3 minutes.

Figure 2-1

Output power versus time and temperature

Calculating size of an AC load

Operating time

To determine how long you can run your appliances:

1. List all the AC loads you think you will use and determine their

power requirement. You can usually find this information on a label
near the power cord on the appliance.

2. Look in

Table 2-1

to find its operating time or the operating time of a

similarly sized appliance. The operating times shown in the table are
the maximum time the appliance will operate. The unit will shut
down after that time so the battery is not drained past a safe level.

3. To find the running time for several appliances running

simultaneously add the total watts of the appliances and look for an
appliance with similar power requirement in

Table 2-1

.

Battery
condition

The information in

Table 2-1

assumes:

there is a properly maintained 400 amp-hour battery bank

the batteries have not been damaged by deep discharge and are
relatively new

0

500

1000

1500

2000

2500

3000

1

10

100

Time (minutes)

Out

put

Power

(

V

A)

-40 to 25C

40C

55C

70C

85C

2

3

4

5

6 7 8 9

– 40 to 77 F

104 F

131 F

158 F

185 F

Advertising