Det-Tronics R8471NH34001,2,3 Single Channel Gas Controller, NH3 - Manual (Page 17)

15 95-8529 1.1
Latching/Non-Latching Relays
The Low and Auxiliary alarm relays are programmable
for latching or non-latching operation. The High
alarm relay is always latching (to ensure that a high
alarm condition cannot go unnoticed). Latching
relay operation is programmed using rocker switch
1 at SW1 (SW1-1). For latching operation, place
the switch in the closed position. For non-latching
operation, place it in the open position. This switch is
set at the factory for non-latching relay operation.
Normally Energized/De-Energized Relays
The three alarm relays are programmable for normally
energized (fail-safe) or normally de-energized
operation. This is accomplished by setting rocker
switch 2 at SW1 (SW1-2). For normally energized
alarm relays, place the switch in the closed position.
For normally de-energized operation, place it in the
open position. This switch is set at the factory for
normally de-energized operation.
The Fault relay is always normally energized,
regardless of the setting of SW1-2.
NOTE
If the switch positions of SW1 are changed while
power is applied, power must be cycled for the
change to take effect.
4 to 20 ma Output
Isolated or non-isolated operation of the 4 to 20 ma
output is selected using a jumper plug at J1. (See
Figure 14 for location of jumper plug.) For non-
isolated operation, as illustrated in Figure 11, place
the jumper plug in the INT (internal power source)
position. Place the plug in the EXT position for an
isolated circuit (external power source), as illustrated
in Figure 12. The jumper is set at the factory for non-
isolated operation.
INSTALLATION CHECKLIST
The following checklist is provided as a means of
double checking the system to be sure that all phases
of system installation are complete and have been
performed correctly.
1. Junction boxes are mounted securely and sensors
are pointing down.
2. All cable shields are properly grounded.
3. All junction box covers are tightly installed.
4. Explosion-proof conduit seals have been installed at
all junction box entries (if conduit is being used).
5. Sensor to controller wiring is correct.
6. Power wiring to the controller is installed and power
source is operational.
7. External loads are properly connected to the
controller.
8. Controller is programmed as desired. Record this
information for future reference.
9. Controller is properly installed in the mounting rack.
10. Proper ventilation is provided to prevent over-
heating of the controller.
Proceed to System Startup, Setpoint Adjustment, and
Calibration.