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1.5.3 Discrete Alarm Relay Board (Option 46R)
As an optional accessory, La Marche offers a discrete alarm relay
board. The
S2A-198B relay alarm board offers additional
customer connection for remote annunciators. The alarm relay
board includes
two
form C contacts for each of these specific
alarms. In this way the customer may be better informed of
which specific alarm has triggered.
These relay contacts cover the following conditions: High Voltage
Shutdown, Low DC Current, High DC Voltage, Low DC Voltage,
Battery End of Discharge, Positive Ground, Negative Ground and
Charger Failure.
0.5A 125VAC
0.25A
125VDC
2A 30VDC
* The Summary and AC Fail alarm relays located on the 368S
card must be wired according to UL Class II wiring guidelines
Table 7 – Alarm Form ‘C’ Contact Ratings
All alarms contacts for the A77 are designed to be fail-safe. In other words, if both the AC and DC power are
removed, each alarm will be indicating in its correct state. To accomplish this, certain alarm relays are de-
energized on failure (such as AC Failure), and certain alarm relays are energized on failure (such as High DCV).
All relay contacts are shown in the de-energized state on schematics. Set A alarms are shown in non-alarm
state on the schematic. Set B alarms are shown in alarm state on the schematic. Customer alarm connections
should be made accordingly. Refer to Table 8.
Figure 8 - Customer Connections to
Discrete Alarm Contacts
Summary of Contents for A77
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