F3 Series Charger Manual
10
HIGH DC SHTDN
Indicates that the charger has been shut down by the high output voltage shutdown circuit. Probable
causes of a high DC shutdown are as follows:
a) The float or boost voltages have been increased above the pre-set shutdown voltage
b) The high voltage shutdown set point has been changed from the factory setting.
c) The charger has malfunctioned, and is not regulating properly.
There is a delay of approximately 5 seconds after the onset of the high voltage condition until the unit
shuts down. When a high volt shutdown occurs, the red HVS LED on the control board will illuminate,
along with the SHUTDOWN LED on the front panel.
If the high DC shutdown activates the charger will stay off until the battery voltage drops to
approximately nominal, at which point the circuit will reset and the charger will start. Manual reset of the
shutdown is accomplished as follows:
1) Turn off the AC input breaker. (Note that while the SHUTDOWN LED will extinguish, the charger is
still locked out. This is because the shutdown LED is driven by the control board's power supply,
which is derived from the AC supply, rather than from battery).
2) Turn off the DC output breaker.
3) Wait for about one minute for capacitor voltage to decay through the capacitor bleeder resistor
4) Turn on the DC output breaker
5) Turn on the AC input breaker. If the charger is still in high DC shutdown, repeat steps 1 through 3,
waiting longer before turning DC and AC breakers back on.
The control board includes two sets of Form C contacts for high volt shutdown indication. Either one of
these can be used for remote indication of high voltage shutdown.
GROUND (optional)
This is a ground fault alarm. If either the charger’s positive or negative is connected to ground, even
through a high resistance path, this alarm will activate. LEDs indicate either positive or negative
grounding. The Form C contact only indicates that a fault has occurred.
Some applications require that ground be referenced to either the positive or negative output. In this case,
the activated ground fault alarm will be a nuisance. The alarm can be safely disabled by placing the
ground fault jumper located on the alarm board (mounted on the charger’s front door) in the “disabled”
position. When pins 1 and 2 of J5 are connected together the ground fault alarm is disabled. When pins 2
and 3 are connected the ground fault alarm is enabled.
4
Adjustments
4.1
Output Voltage Adjustment
WARNING:
Working inside the charger exposes you to dangerous AC and DC voltages. Do not touch
circuit breakers, filter capacitors, heat sinks or any other exposed metal surfaces
NOTE:
Do not tamper with factory adjustments unless sure adjustment is necessary. Temperature-
compensated control circuitry automatically adjusts the output voltage depending on temperature. Adjust
the output only under these circumstances:
a) To correct a previous unauthorized adjustment
b) To adjust the charger for a different type of battery (e.g. from lead-acid to nickel-cadmium)
c) If your battery is consistently being over-charged or under-charged
NOTE:
Unless authorized by SENS, any charger adjustment, including output voltage adjustment, voids
the warranty.
Procedure
1. Use a precision external voltmeter connected directly to the charger output terminals.
2. Set the charger’s front panel FLOAT/BOOST control to FLOAT.
3. Open the charger’s front panel and locate the control card. It contains two potentiometers labeled
