Xantrex C12 Charge/ Load / Lighting Controller Owner’s Manual
2
975-0130-01-01
Introducing the C12
The Xantrex Technology C12 charge/load controller is the finest small
system charge/load controller available and has many capabilities
previously either non-existent, or found only in separate products.
Numerous standard features maximize the performance of the system:
•
Designed to meet the National Electric Code and other international
controller specifications. ETL certified for the U.S. (UL Standard
1741 (draft)), and Canada (CSA-C22.2 No. 14-M91 SEP 91).
•
Electronic overload and short circuit protection with automatic and
manual reset ability. Increases the reliability of unattended systems
by eliminating blown fuses or tripped circuit breakers.
•
Field adjustment of the setpoints is provided by rotary controls with
removable knobs to reduce the potential for setpoint tampering.
Includes calibrated scales for adjustment of the settings and
testpoints to verify setpoints using a digital meter (not required).
•
Optional external plug-in temperature compensation sensor for
automatic adjustment of the charge controller setpoints to the
battery temperature. This UL requirement is also strongly
recommended for sealed batteries.
•
Over-temperature protection of the electronic circuitry is provided by
reducing the charge rate. This improves the reliability of the C12
when used in very hot environments (over 113
°
F / 45
°
C ambient).
•
Outdoor rain-tight powder coated enclosure for pole or wall
mounting.
•
Multi-color LED with matching color label for mode/status indication.
•
2 year limited warranty
These instructions only apply to the C12 REV D or later.
Operating Modes
The model C12 charge/load controller can operate in one or more of
the following modes:
•
Photovoltaic Charge Control Mode
with 3-stage
regulation and automatic or manual battery equalization cycle.
•
DC Load Control Mode
includes automatic low battery
disconnect with warning by flashing the loads. In manual mode the
reset switch allows one 10-minute “grace period” of load operation.
•
NITE-LITE Mode
with automatic dusk detection and adjustable
time period from 10 minutes to 9.5 hours duration or dusk to dawn
operation with a 20 hour limit.
Photovoltaic Charge Control Mode
3-Stage Regulation
The C12 charge controller rapidly cycles the photovoltaic array on and
off to control the charging of the battery. The battery voltage will vary
during the charging process, as follows:
1.
BULK
—During this stage the PV array is allowed to charge at its
full output. Once the voltage of the battery reaches the BULK
voltage setting, the controller goes to the next stage.
2.
ABSORPTION
—During this stage the voltage of the battery is
held at the BULK voltage setting until a timer accumulates 1 hour.
3.
FLOAT
—During this stage the voltage of the battery is held at
the FLOAT voltage setting. Full current from the PV array can still
be delivered to the loads during this stage.
If the voltage of the battery drops below the FLOAT setting for a
cumulative period of one hour, a new BULK or ABSORPTION cycle
will be triggered. This typically occurs during each night. If the battery
is full at the start of the day, it will receive only an ABSORPTION
charge for 1 hour and then be held at the FLOAT setting for the
remaining period of the day unless the battery is discharged.
This 3-stage charging process results in faster recharging of batteries
compared to on-off or constant voltage regulators. Faster recharging
increases the performance of the system by storing more of the PV
array’s limited output. The final FLOAT voltage setting reduces
gassing of the battery, minimizing watering requirements and ensuring
the complete recharge of the battery.
Automatic PV Array Night Disconnection
Each night the PV array is automatically disconnected from the battery
to prevent reverse leakage of power. This eliminates the need for a
blocking diode between the battery and the PV array. If you are using
thin-film or amorphous solar modules, diodes may still be required to
prevent damage from partial shading conditions. Check the
documentation provided for the requirements of your PV modules.
Equalization (Non-Sealed Batteries Only)
Approximately every month, the batteries may need to be "equalized"
(a fancy term for over-charged). Since the individual cells of the
battery are not identical, some cells may not be fully charged when the
charging process is completed. Or, if the batteries have been left
uncharged for periods of time, the plates will have sulfates on them. If
the sulfate remains on the plates for an extended period of time, it will
harden and seal off a percentage of the plate area, reducing the
capacity of the battery. By equalizing the batteries, the sulfate is
removed from the plates.
Additionally, batteries with liquid electrolyte may become stratified.
Stratification concentrates the sulfuric acid into the bottom of the cell
while the top becomes diluted. This corrodes the lower portion of the
plates, reducing battery life. Mixing of the electrolyte by the formation
of gas bubbles during the equalization process reduces stratification.
You can check if a battery needs to be equalized by two methods. If
you can measure the voltage of each individual cell, a variation of 0.05
volts between cells indicates an imbalance exists. If the battery
construction prevents measurement of the individual cell voltages, use
a hydrometer. If you can measure the specific gravity of each of the
battery cells, a variation of 0.020 is considered significant. Both
conditions may be corrected by an equalization charge.
A proper equalization charge will not damage a vented, liquid
electrolyte type battery. It may, however, cause significant electrolyte
usage and require that the battery be refilled with distilled water to the
correct level. This may be a problem with unattended systems in
remote areas that do not receive regular maintenance. Consult the
battery manufacturer for their recommendations.
CAUTION:
Equalization should only be done with vented (not
sealed or maintenance free) lead acid, liquid electrolyte batteries.
The battery manufacturer should be consulted before attempting
to equalize any other type battery. Clean, distilled water will need
to be added to the battery AFTER the equalization process.
DC loads may need to be disconnected by turning off circuit
breakers or removing fuses before equalization to prevent
damage by the required higher voltages. Just turning off the DC
loads by its on/off switch may not provide protection.
WARNING:
If the batteries are equipped with HYDROCAPS
(catalytic gas recombiner caps), they should be removed during
the equalization process. If hydrocaps are used, you should
disable automatic equalization to prevent possible damage.
The C12 includes both automatic and manual triggering of the
equalization process. Automatic equalization is enabled by removing
the jumper located on bottom right corner the circuit board next to the
reset switch (the default setting is disabled). An equalization charge,
(holding the voltage 1 volt above bulk for 2 hours) will occur every 30
days or once the system has reached the LVD level for a period of two
minutes or longer. The default setting is auto equalization disabled.
Manual equalization is not available when the C12 is used in the NITE-
LITE mode because the reset switch provides a test function of the
loads instead (this only applies to the NITE-LITE mode).