End Of Discharge Alarm Relay; Current Limit Alarm Relay; Cabinet Heater Strips; High And Low Ac Voltage Alarm Relays - HindlePower SCR series Operating Instructions Manual

14. END OF DISCHARGE ALARM RELAY (EJ0143) WITH OPTIONAL LIGHT
Purpose and Description: The EDA option provides a low-limit threshold voltage set at the lowest
safe voltage to which the batteries may be discharged. The remote relay terminal connections may b used
to operate a system load disconnect circuit by tripping a shunt trip DC load circuit breaker or opening a
DC load contactor.
The factory preset threshold for alarm condition is as follows unless otherwise specified:
1.75 volts/cell for LEAD ACID
1.00 volts/cell for NICKEL CADMIUM
15. CURRENT LIMIT ALARM RELAY WITH INDICATING LIGHT (EJ0137)
Purpose: The Current Limit Alarm provides an alarm signal whenever the battery charger output
reaches the maximum limit set by the current limit circuit. An indicator, DS24, on the front panel also
lights when the current limit alarm is activated.
Description: The CLA PC Board assembly, A18, continually monitors the output of the current limit
circuit on the charger control module, A1. When the current limit circuit indicates that the charger output
is in current limit, the circuitry of A18 closes relay K24, providing an alarm at TB3 terminals 25, 26, 27. A
several second delay is built into A18 so that brief excursions into current limit caused by load changes
will not result in an erroneous alarm indication. When the battery charger comes out of current limit, the
alarm will be automatically reset.
16. CABINET HEATER STRIPS (EJ0145)
Purpose and Description: This option provides a method of maintaining a dry charger interior in high
humidity environments. Strip heaters are placed inside the charger cabinet and wired to a separate 120
volt, single phase source (customer supplied). Heaters are off/on controlled by a fixed thermostat TH1.
The thermostat opens on rise at approximately 80 °F and resets (recloses) at approximately 70 °F. Strip
heaters are shielded in order to prevent accidental human contact.
17. HIGH AND LOW AC VOLTAGE ALARM RELAYS WITH INDICATING LIGHTS (EJ0155)
Purpose: The HLAC Alarm relay provides an indication whenever the AC input voltage deviates
beyond preset limits. The limits are set at the factory at 115% and 85% of nominal AC input voltage,
respectively. Indicator lights on the battery charger front panel are provided for each condition.
Description: The HLAC Alarm relay operates similarly to the High-Low DC voltage alarm relay. AC
voltage is converted to DC by the AC detector PC Board assembly, A11B. The filtered signal from that
board is measured at the alarm PC Board assembly, A11A. If the measured signal is not within an
acceptable range, an alarm signal is presented at TB3, and the appropriate indicator is lighted on the front
panel. The alarm board assembly has a built-in delay to prevent line voltage surges and sags from causing
erroneous alarm indications. When the AC line returns to within acceptable limits, the alarm indications
will be reset.
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