Control And Alarm Relay Contact Information; Table 2-2 Control Relay Contact Information; Table 2-3 Alarm Relay Contact Information; Control Relays - Honeywell UDC3500 Product Manual

2.4 Control and Alarm Relay Contact Information

Control Relays

ATTENTION
Control relays operate in the standard control mode (that is, energized when output state is on).
Unit Power
Off
On

Alarm Relays

ATTENTION
Alarm relays are designed to operate in a failsafe mode (that is, de-energized during alarm
sate). This results in alarm actuation when power is OFF or when initially applied, until the unit
completes self-diagnostics. If power is lost to the unit, the alarms will de-energize and thus the
alarm contacts will close.
Unit
Power
Off
On
10/05

Table 2-2 Control Relay Contact Information

Control Relay
Wiring
N.O.
N.C.
N.O.
N.C.

Table 2-3 Alarm Relay Contact Information

Alarm Relay Variable NOT in Alarm State
Wiring
Relay
Contact
N.O. Open
N.C. Closed
N.O. Closed
N.C. Open
UDC3500 Universal Digital Controller Product Manual
Control Relay
Contact
Open
Closed
Open
Closed
Closed
Open
Variable in Alarm State
Indicators Relay
Contact
Open
Off
Closed
Off Open
Closed
Installation
Output #1 or #2
Indicator Status
Off
Off
On
Off
On
Indicators
Off
On
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