MX28B 15
Table 5.6-1. External Alarm Input Definition
Table 5.6-2 shows the external alarm input connection designations. Connector J4 is
located on the interface card mounted in the top left side of the unit. Systems are shipped
with jumper wires connecting each NC and corresponding C contact. A jumper wire should
be removed only if the corresponding NC-C contacts are going to be used.
EXTERNAL
ALARM
INPUT
J4 TERMINAL
DESIGNATION
(NO-NC-C) USER ALARM NOTES
#1
#2
#3
#4
NO1-NC1-C1
NO2-NC2-C2
NO3-NC3-C3
NO4-NC4-C4
__________________________
_
__________________________
_
__________________________
_
__________________________
_
Table 5.6-2. External Alarm Input Connections
5.6.2 Alarm Outputs
There are eight alarms available that provide outputs via Form “C” relay contacts. The last
two of these are preassigned as the Minor and Major alarm outputs. The Major relay is
energized (NO-C contacts closed) during normal (non-alarm) operating conditions; all the
other relays energize when an alarm condition occurs. The other six outputs are initially
designated as “Relay 1” through “Relay 6” (the user may assign more meaningful names if
desired). The various system alarm conditions can be assigned to any of the eight alarm
outputs.
Table 5.6-3 shows the alarm output connection designations. Connectors J1 and J2 are
located on the interface card mounted in the top left side of the unit. The relay contacts
should only be used to switch resistive loads of 0.5 amperes or less at 60 volts or less.
External Alarm Source
(non-alarm state) Connect To Input
Alarm Terminals
OPEN
CLOSED NO-C
NC-C