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(step 1 cont.)
B) Check the LVD FET (if controller is equipped with LVD) by measuring a diode drop between Battery (+) and Load
(+) terminals. If no diode drop is present or if an open circuit is measured, the LVD FET is damaged. If no diode drop is
present (short circuit), the unit will still (most likely) regulate the battry voltage properly, however the controller will no
longer have LVD capability.
C) Check for continuity between the ground connections on the terminal strip (PV (-), Battery (-), and Load (-).
D) Remove the four screws from the face plate. Bend a small hook in one end of a 12AWG solid wire. Insert the hook
into one of the screw holes and pull off the face plate. The face place may be stuck to the internal potting and may make
a cracking sound when removed. This is normal and will not demage the internal circuitry. Inspect for burns, damaged
traces, etc.
Step 2: Battery Connected to Battery Terminals Only
Note: The green “charging” LED should be off.
A ) Measure the voltage at the battery terminals.
B) Measure the voltage at the load terminals. The voltage should be the same(+/- 200mV) as the battery voltage.
If load
voltage is signifi cantly lower than battery voltage, LVD FET’s or the power traces inside the SunSaver are damaged.
C) Measure the voltage at the Solar (PV) terminals. The voltage should be less than 2.5 Vdc. If green LED is on, or bat-
tery voltage is measured at Solar terminals, the input FET’s are damaged and the unit will not regulate battery voltage
properly.
Step 3: PV and Battery Power Applied to the Controller:
Note 1: The green “charging” LED should be lit
A)The voltage across the PV terminals should be the same as the
voltage across the Battery terminals if the battery is not fully
charged.
B)If the batteries are charged, there will be a voltage difference
between the PV (+) and Battery (+). If your multi-meter has a
frequency measuring option, a 300Hz AC signal should be
measured between the PV (+) and Battery (+). The duty cycle
of this signal can be used to give a rough indication of the battery
state of charge. A lower duty cycle indicates a battery with a
higher state of charge.
Regulated
Power Supply
+
-
Battery
Load
+
-
+
-
+
-
Battery
