* 208 VA to 230 VA are based on 230 V operation.
Control wiring
The unit can operate out of the box with no control
wiring connected to it.
The main control board and two refrigeration
boards come standard on every unit (Figure 22).
The unit can have an optional factory installed
customer terminal board that can be used to
reference and provide inputs to numerous
components and sequences (Figure 22).
The unit can also have an optional factory installed
options board. While the options board is not
standard, if the unit is ordered with an option that
requires this board, it is automatically installed at
the factory (Figure 22).
Field control wiring MUST be a minimum 20 AWG
and should contain a shield.
Consult the wiring diagrams shipped with the unit,
or use the QR code on the unit nameplate to view
them on the RTUToolkit app.
For field wiring diagrams, see Figure 23 and Figure
24 and Figure 25.
Occupancy input
•
The unit can accept a hardwired 24 VAC input
for occupancy status
•
24 VAC present at the W4 terminal on the
main control board puts the unit into OCC
mode
•
24 VAC must be provided by the main control
board
•
On the main control board, wire between W10
(24 VAC output) and W4 (OCC-S input) (Figure
Safety switch input
•
The rooftop unit can accept a safety switch
input that can immediately shut down all unit
operation.
•
The safety switch input is on terminal W5 on
the main control board.
•
When 24 VAC is not present at the safety
switch input, the unit shuts down all
operation.
•
24 VAC must be provided by the main control
board.
•
On the main control board, wire between W11
(24 VAC output) and W5 (SS-S) Figure 21.
•
Minimum run times are ignored when a safety
switch input is received.
•
There is a factory installed jumper on the
main control board between 24 VAC and
terminal W5 when the unit leaves the factory.
Figure 21: Safety switch input and occupancy input status
Main control board
See Figure 25 for field wiring.
Customer terminal board
•
The unit can have an optional customer
terminal board (see Figure 23 for field wiring).
•
This terminal board can be used to reference
numerous devices and provide numerous
inputs for different unit sequences.
•
The board also accepts hard wired
temperature and humidity sensors used to
control the unit.
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
69
Tempmaster
