Installation
18 UDC3300 Expanded Model: DC330E User Manual 5/00
Control Relays
ATTENTION
Control relays operate in the standard control mode: i.e., energized when output state is
on.
Table 2-3 Control Relay Contact Information
Unit Power Control Relay
Wiring
Control Relay
Contact
#1 or #2 Output
Indicator Status
N.O. Open
Off
N.C. Closed
Off
N.O. Open
Closed
Off
On
On
N.C. Closed
Open
Off
On
Alarm Relays
ATTENTION
Alarms relays are designed to operate in a failsafe mode; i.e., de-energized during alarm
state. This results in alarm actuation when power is OFF or when initially applied, until the
unit completes self-diagnostics. If the unit loses power, the alarms will function.
Table 2-4 Alarm Relay Contact Information
Variable
NOT in Alarm State
Variable
in Alarm State
Unit
Power
Alarm
Relay
Wiring
Relay
Contact
Indicators
Relay
Contact
Indicators
N.O. Open Open
Off
N.C. Closed
Off
Closed
Off
N.O. Closed Open
On
N.C. Open
Off
Closed
On