TK 56940-11-IS Revision A ©2021 Trane Technologies 1
Overview
This retrofit kit replaces the existing contactor box in your HVAC unit.
IImmppoorrttaanntt:: TE15 M1, TE15 M1A and TE15 M2 units require an additional ground wire (424991
sold separately) to ground the contactor box to the bus unit common ground stud.
IImmppoorrttaanntt:: Software version needs to be 4.02.04 or higher. Refer to manual 54650 for software
flashloading instructions.
RCS1730
Installation Manual
1 2 34
Item Part Number Description Qty.
1. NSS Contactor box assembly (shown with cover removed) 1
2. NSS Band wrap, 6.575” long 24
3. NSS Band wrap, 3.00” long 12
4. NSS Installation instructions 1
Installation Instructions
TE14/TE15 Bus Contactor Kit 401596
2©2021 Trane Technologies TK 56940-11-IS Revision A
Installation Procedures
Contactor Box Removal
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1. Locate the contactor box in your HVAC unit and remove cover.
NNoottee:: Before removing any wires, note how they are routed into the box for reference later.
2. Disconnect and remove the following wires:
a. incoming 3 Phase AC wires.
b. outgoing heater harness wires.
c. outgoing evaporator harness wires.
d. outgoing condenser harness wires.
e. any shielded/ground connections to box.
f. Disconnect the 12 pin connector mounted on the outside of box.
3. Remove the four ¼-20 screws and remove box from unit.
• Retain hardware for reuse.
• The box and cover will not be reused.
Contactor Box Installation
1. Remove the cover from the new contactor box.
2. Route wire harnesses into the box as they were originally.
3. Install contactor box and secure with hardware removed earlier and tighten securely.
4. Reconnect wires per FFiigguurree 11.. NNeeww CCoonnttaaccttoorr KKiitt IInnssttaallllaattiioonn WWiirriinngg DDiiaaggrraamm oonn ppaaggee 33.
5. Torque wires in contactors and terminal blocks per the following torque specs.:
a. All contactors: 10-12 in-lb
b. All terminal blocks: 13.3-15.9 in-lb
6. Reconnect the 12 pin connector mounted on the outside of box.
7. Reinstall the cover onto box.
TK 56940-11-IS Revision A ©2021 Trane Technologies 3
Figure 1. New Contactor Kit Installation Wiring Diagram and Torque Specs.
RCS1733-2
10-12 in-lb
13.5-15.9 in-lb
22-26 in-lb
24-26 in-lb
4©2021 Trane Technologies TK 56940-11-IS Revision A
Figure 2. Contactor Box Wiring Diagram
(TE15 M1, TE15 M1A and TE15 M2 require additional ground wire 424991 shown)
RCS1731-3
Circuit Breakers Contactors
Terminal Block
424991
TK 56940-11-IS Revision A ©2021 Trane Technologies 5
Figure 3. All Torque Specs. Shown
24-26 in-lb
15-18 in-lb
12.39 in-lb
15-18 in-lb
15-18 in-lb
15-18 in-lb
22-26 in-lb
10-12 in-lb
10-12 in-lb
13.3-15.9 in-lb
22-26 in-lb
RCS1743
6©2021 Trane Technologies TK 56940-11-IS Revision A
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