5-4
Some or all of these output functions could be implemented using addressable
devices or other relay modules instead, in which case the corresponding NAC output
could be reassigned to other uses. The new configuration would require full testing
of these functions to ensure compliance with AS 4428.1.
To connect the SPS to reverse-polarity, non-addressable notification appliances using
Class A wiring, read the following instructions and refer to the figure below.
1. Route wire from the “B+”, “B-”, outputs on TB2 of the SPS to the appropriate
inputs on a peripheral notification appliance. Use NAC1, NAC2, or NAC3 as
required.
2. Route wire from the first appliance to the next one. Repeat for each appliance.
3. Route wire from the last appliance to the A+ and A- inputs on the same NAC
circuit of TB1 of the SPS.
4. Repeat steps 1 through 3 for each NAC output you want to use.
5. Leave the 10 K, ½ W, brown/black/orange resistor (378-030) on each the “B+”
to “B-” terminals of each unused NAC. No external end-of-line resistor is
needed for circuits in use.
6. If the appliance/device to be used does not have an integral diode, a sufficiently
rated blocking diode must be fitted between the incoming +ve wire and the +ve
terminals of the device with cathode (stripe) to the device.
P1
3
2
1
B+ B- A+ A-
TYPICAL
APPLIANCE
RED
RED
RED
NAC1
B+ B- A+ A-
NAC1
B+ B- A+ A-
NAC1
LED1 LED2 LED3
TYPICAL
APPLIANCE
BLK
BLK
BLK
NAC2 NAC3
Figure 5-2. Class A (loop) NAC Wiring
Continued on next page
SPS NAC Field Wiring Guidelines, Continued Class A (loop) NAC
Wiring
0.75 mm
2
to 4 mm
2
Important: Conductors
must test free
of all grounds. Leave the 378-030 EOL
Resistor (10 K Ohm, ½ W;
brown/black/orange) on
unused B+/B- terminals
Ferrite beads
required for EMC
compliance. Use
SX0005 or kit
4100-5129.
NAC1 NAC2 NAC3