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MUL
TI V Split Rooftop Unit Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
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Communications Cable Specifications Between Multiple RTUs
Operating as a Group (Group Control)
If any RTUs were specified to operate in unison:
• Before running cable, decide which RTU will be the “Main.” The other RTUs in that group will be designated as “Sub(s).” The zone controller
will be connected to the Main.
• Set the pertinent DIP switch at each RTU to identify the Main and Sub(s).
• Use a daisy chain configuration and connect all of the group’s RTUs together starting at the “Main” unit.
•
NEVER splice, cut, or extend cable length with field provided cable. Always include enough cable to cover distance between all com-
ponents.
• Perform group control settings and connect the group control wiring after the system auto address and auto pipe procedures have been
completed.
For RTUs with hardwired connections SIG - 12V - GND (Comm.) terminals:
• From the controller to the main RTU, use 22 AWG, 3-conductor, twisted, stranded, unshielded. All wiring must comply with all applicable
local and national codes.
• From the main RTU to the sub RTU(s), daisy chain using 22 AWG, 3-conductor, twisted, stranded, unshielded.
(
Do not attach wire to 12VDC terminal to the sub RTUs). All wiring must comply with all applicable local and national codes.
For RTUs with CN-REMO connections:
Use Group Control Kit (sold separately) containing extension and Y-splitter cables. Use one (1) group control cable kit for each RTU in the
group except for the last RTU.
ELECTRICAL
Communication Cable Specifications
• Cable connected to zone controller is the factory default connection.
Figure 37: Example of RTU Group to Zone Controller Connections (Sig-12V-GND [Comm.] Terminal).
Main Split Rooftop Unit
Split Rooftop Unit
Signal
12VDC Comm.
Signal
12VDC Comm.
4
5
6
Signal
12VDC Comm.
Signal
12VDC Comm.
Split Rooftop Unit