11
2.6 Installing
External
Temperature Compensation (Option 11W/11Y)
The natural voltage of a battery changes as a function of temperature change. As the battery temperature
rises, the effective voltage of the battery decreases. Without Temperature Compensation, the battery charger
will always produce a set constant output voltage. As the battery temperature increases, this constant voltage
will then induce a higher output current from the charger. This higher current can result in overcharging the
battery, which in turn can result in damage to the batteries.
Temperature Compensation combats this overcharging by adjusting the charger’s output voltage based on the
temperature read by the temperature probe. In order to increase the accuracy of the temperature
compensation the external probe can be used to measure the temperature of the battery.
Option 11W includes the compensation circuit and a 24 foot long temperature probe. Option 11Y includes the
compensation circuit and a 100 foot long temperature probe. With either option approximately two feet of the
probe is taken inside the charger enclosure.
External Probe Connection Procedure
Before making any connections to the A75D(E) ensure that the AC Power is off at the main breaker box and
that both of the unit’s breakers are off. Verify that no voltage is present by using a voltmeter at all input and
output terminals. Check that the jumper on the pins on the
S2A-364
(above the temperature compensation
contacts) is connected to JP3. Disconnect the internal temperature sensor. Connect the black lead of the probe
to the negative
(-)
contact, and the red lead to the positive
(+)
contact. To disable temperature compensation,
simply move the jumper to the JP4 pins.
Figure 10 - Temperature Compensation Connection Diagram
