Specifications

20
20.0 BATTERY TEMPERATURE COMPENSATION (OPTION)
20.1 The temperature compensation option comes with a temperature probe and 20-
foot cable. The probe is a thermistor which is connected to J1 pins 6 and 8.
There is no polarity for this connection. The probe is used to monitor the tem-
perature of the battery and adjust the rectifier output voltage accordingly. As
battery temperature increases, rectifier output voltage decreases.
20.2 The change in output voltage with temperature is -3.75mV/
0
C per battery cell,
centered at 25
0
C. For example, for a +10
0
C temperature change from 25
0
C with
the rectifier charging a 48V battery, the change in the rectifier output voltage
would be:
20.3 The probe can be located in several possible places: right on the battery to
detect the battery temperature, near the battery in free air to detect the local
ambient temperature, or on the power plant metal frame near the battery.
20.4 If the TC probe is either opened or shorted, the rectifier outputs revert to the
float voltage.
20.5 Setting the Temperature Compensation Voltage.
20.51 Make sure that the float voltage was set with the temperature probe
disconnected.
20.52 Before connecting the temperature probe, record the float voltage to
three digits.
20.53 Connect the temperature probe to terminals 6 and 8 of J1.
20.54 With the temperature probe at approximately 25
0
C ambient temperature,
adjust the front panel TC potentiometer until the rectifier output voltage
as read on an external voltmeter is exactly the same as the previously
recorded float voltage.
48
2
= 24 cells
V = 24 cells x 10
0
C change x (-3.75mV/
0
C) = -900mV = -0.9V