Class b (string) nac wiring, Class b (string) nac wiring -5, Figure 5-3. class b (string) wiring -5 – Tyco 4100U-S1 User Manual
Page 73: Sps nac field wiring guidelines, Continued, Figure 5-3. class b (string) wiring

5-5
To connect the SPS to appliances using Class B 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. “T” tapping is not allowed
since the spur will not be supervised. Repeat for each appliance.
3. Route wire from the last appliance to the supplied EOLR or a 4081-9008 EOL
Harness (10 K Ohm, ½ W; brown/black/orange).
4. Repeat steps 1 through 3 for each NAC output you want to use.
5. Leave the 378-030 EOL Resistor (10 K Ohm, ½ W; brown/black/orange) on
each unused circuit. The circuit must connect “B+” to “B-” terminals.
6. If the appliance/device to be used does not have an integral diode, a blocking
diode must be fitted between the incoming +ve wire and the +ve terminal of the
device with the diode’s cathode (stripe) connected to the device.
The illustration below shows Class B wiring.
P1
3
2
1
B+ B- A+ A-
TYPICAL
APPLIANCE
RED
BLK
NAC1
B+ B- A+ A-
NAC1
B+ B- A+ A-
NAC1
LED1
LED2
LED3
TYPICAL
APPLIANCE
10K 1/2W (133-894)
NAC2
NAC3
RED
RED
RED
RED
Figure 5-3. Class B (string) Wiring
SPS NAC Field Wiring Guidelines,
Continued
Class B (string) NAC
Wiring
Important: Conductors
must test free
of all grounds.
0.75 mm
2
to 4 mm
2
BLK
BLK
BLK
EOL Harness
Leave the EOL Resistor
(10 K Ohm, ½ W;
brown/black/orange) on
unused B+/B- terminals
Ferrite bead
required for CE
compliance. Use
kit 4100-5129.
NAC1
NAC2
NAC3