Trouble Relay; Trouble Relay Connection Wiring; Remote Reset - MSA Chillgard RT Instruction Manual

Trouble Relay

There is one relay (the Trouble relay) within the unit that indicates that a
trouble or start-up condition exists. This relay is configured from the
factory and operates differently than the alarm relays. It operates in a
normally-energized mode.
This relay is energized when the instrument is:
• normally operating,
• in the calibration mode, or
• in the setup condition.
The relay is de-energized when:
• a fault is detected,
• the unit is in the start-up state, or
• the main power is lost.
This means that power is no longer provided to the relay coil. It is not
possible to change the configuration of the Trouble relay.
The relay connector function or identification:
• NORMALLY OPEN (NO),
• COMMON (COM),
• NORMALLY CLOSED (NC)
as marked in FIGURE 2-5 refers to the relay contacts as if the relay is
de-energized or in the trouble condition. A relay contact is provided
between the Normally Closed (NC) and Common (COM) position. This
contact will be made in the event that main power to the unit is lost or
any other trouble condition exists.

Trouble Relay Connection Wiring

The Trouble relay wiring should enter the unit through one of the entries
on the right side of the unit. Connections are made at the internal
terminal strip labeled J29, positions 1, 2 and 3 (located on the right side
of the circuit board - FIGURE 2-5). The terminal portion of the connector
can be unplugged from the circuit board for easier wire connections.
The maximum wire size that these connectors can accept is #12 AWG.

Remote Reset

The audible alarm and latched refrigerant level alarms can be remotely
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