Installation and Operation Manual
8
functioning and adjustment can be made. Verify that the LED remains on at the maximum current adjustment point, and as you check for a slight drop in
current on either side of the maximum point. If LED does not remain on, MPPT is not operating due to a combination of high PV temperature and/or high
battery voltage. MPPT can usually be made to operate by lowering battery voltage through application of a heavy DC load. If in doubt, leave the adjustment
at the factory default position of midway between 11:00 and 12:00 o’clock as shown in Figure 3. Note that the LED briefly turns off every 10 seconds while
the system recalculates the MPPT operating point.
TROUBLESHOOTING GUIDE
SYMPTOM
PROBABLE CAUSE
ITEMS TO EXAMINE OR CORRECT
Completely dead, no
display
No battery power
Battery disconnected, overly discharged, or connected reverse polarity. Battery powers the
system, not PV. Battery voltage must be present for unit to operate.
Display OK, but
system will not turn on
(charge status LED
off)
PV disconnected
PV reverse polarity
PV- connected to BAT-
Verify PV connection. Requires PV to supply at least 0.15A at
≈
14V to begin charge.
Reverse polarity PV will cause front panel to heat, and display to show “negative” PV current
if battery is connected.
PV- & BAT- must be separate for proper operation. PV- must receive earth ground via shunts
in the 2000E which internally connect PV- to BAT-. External connection prevents proper
operation of the internal current measurement system.
Charge status LED on
in Bulk, but no output
charge current
Dip switches set incorrectly
Low PV power
Double check dip switches #1-4.
Correct PV’s.
Charge status LED on
& blinking in Constant
Voltage mode but no
output charge current
Battery voltage greater than
charge voltage setpoint
Temp comp. enabled without
sensor, or sensor failed open
Battery voltage too low
This is normal operation. Output is off due to high battery voltage which may be caused by
other charging systems.
Disable temp compensation, or replace sensor. Proper temp sensor terminal voltage when
connected is 2.98V at 25
°
C, changing at +10mV/
°
C.
A minimum battery voltage of
≈
9.0V is required for the unit to operate.
Charge status LED on
in Constant Voltage,
relays click on/off
Charge current is very low and
the system is on the edge of
being able to stay on
PV- connected to BAT-
If charge current is very low (
≈
0.1 – 0.2A) because battery voltage is at setpoint, relays may
switch on/off. This normal and will cause no harm. The on/off symptom will go away with a
slight increase or decrease in battery voltage, or load current.
PV- & BAT- must not connect together external to controller for proper operation.
Relays click on/off
rapidly
Dip switch #2 off
Double check dip switch #2, must always be on. Used for factory test only.
Charge status LED
blinking, charge
voltage high
System in equalize mode
Temp sensor failed short, or
installed reverse polarity
Disable equalize by pressing the equalize pushbutton.
Replace sensor, or remove sensor and disable temp compensation. Proper temp sensor
terminal voltage when connected is 2.98V at 25
°
C, changing at +10mV/
°
C.
Charge current is
lower than expected,
PV current may be low
as well
Battery is highly charged
Worn out PV modules
Low insolation
PV- connected to BAT-
MPPT improperly setup
Normal operation, system will be in Constant Voltage mode and current is reduced to control
battery voltage.
Replace, or use as is.
Atmospheric haze, PV’s dirty, sun low on horizon, etc.
PV- & BAT- must be separate for proper operation. PV- must receive earth ground via shunts
inside the 2000E which internally connect PV- to BAT-. External connection prevents proper
operation of the internal current measurement system.
See Maximum Power Voltage and Optimizing MPPT sections.
MPPT Current boost is
less than expected
PV maximum power voltage
(V
MP
) is not much higher than
battery voltage, leaving little
extra power to be extracted
PV’s hot
MPPT improperly setup
May result from PV’s with low V
MP.
PV’s with higher V
MP
produce greater power and current
boost potential. PV’s with V
MP
≥
17V work best, PV’s with <36 cells tend to work poorly.
Excessive PV wiring voltage drop due to undersize wiring, poor connections, etc., consumes
and wastes available power. This simulates having PV’s with low V
MP
.
Battery is nearly charged and battery voltage is near setpoint. Output during MPPT operation
is “constant power” so higher battery voltage produces less charge current.
V
MP
and available power decrease with increasing PV cell temperature. Cooler PV’s will
produce greater boost. MPPT LED off indicates that extra power is not available from PV
array. It is normal for boost to decrease as temperature rises.
See Maximum Power Voltage and Optimizing MPPT sections.
At high temperature,
unit shuts down
System temporarily shuts
down due to high temperature
Improve ventilation or reduce PV power. Providing sufficient ventilation or operating
conditions which do not cause over temperature shut down will improve reliability.
