13
2.5.2 Understanding the Alarms
Each alarm indication relay in the TPSD is designed as fail-safe. This means that under a complete system
malfunction with all alarm relays de-energized, each alarm will indicate its correct state. Table 9 shows what
state each alarm relay is in under normal running conditions of the charger, no alarms are present.
Alarm Relay
State of the Relay
Normally Open
contacts
Normally Closed
contacts
HVSD De-energized
Open
Closed
HIGH DCV
De-energized
Open Closed
LOW DCV
Energized
Closed
Open
NEG GND
De-energized
Open
Closed
POS GND
De-energized
Open
Closed
AC POWER FAIL
Energized
Closed
Open
SUMMARY Energized
Closed
Open
LOW DCA
Energized
Closed
Open
The
HVSD ALARM will trigger if the output DC voltage of the charger rises above the alarm threshold for
longer than 20 seconds, red “HVSD” LED will turn on. This is usually due to the failure of an internal charger
component, but could also be the result of maladjustments of the output voltage settings. If the high DC
voltage shut down alarm activates the DC output of the charger shuts off the charger to prevent irreversible
damage to the battery. See Section
3.5.1 CUSTOMER CALIBRATION for information on viewing and adjusting
the threshold value.
The
HIGH DCV ALARM will trigger if the output DC voltage rises above the specified voltage threshold of the
alarm for longer than 5 seconds, red “HIGH VOLTAGE” LED will flash. This is usually caused by maladjustments
of the output voltage settings, or in rare cases by a failure of an internal charger component. See Section
3.5.1
CUSTOMER CALIBRATION for information on viewing and adjusting the threshold voltage.
The
LOW DCV ALARM will trigger if the DC voltage drops below the specified voltage threshold of the alarm
for longer than 5 seconds, red “LOW VOLTAGE” LED will turn on. This is usually due to an AC Failure, or the
charger is overloaded into deep-current limit. It could also be caused by maladjustments of the output folage
settings, or in rare cases by a failure of an internal charger component. See Section
3.5.1 CUSTOMER
CALIBRATION for information on viewing and adjusting the threshold voltage.
The
NEG GND ALARM will trigger if any current between the negative terminal of the battery and earth
ground is measured, red “GROUND DETECTION” LED will turn on. A negative ground alarm would signify that
the negative terminal of a floating battery has become grounded. If the charger has ground detection disabled
this alarm will not function.
The
POS GND ALARM will trigger if any current between the positive terminal of the battery and earth ground
is measured, red “GROUND DETECTION” LED will flash. A positive ground alarm would signify that the positive
terminal of a floating battery has become grounded. If the charger has ground detection disabled this alarm will
not function.
Table 9 – State of each Alarm Relay (No alarms present)
