SCXF-SVX01T-EN
63
When opened, the unit shuts down immediately and can be
canceled by closing the switch. Refer to the unit wiring
diagrams (attached to the unit control panel) for proper
connection terminals. The switch must be rated for 12 mA
@ 24 Vdc minimum. This input will override all VOM inputs,
if the VOM option is on the unit.
Occupied/Unoccupied Contacts
To provide night setback control if a remote panel with night
setback was not ordered, install a field-supplied contact.
This binary input provides the building’s occupied/
unoccupied status to the RTM. It can be initiated by a time
clock, or a building automation system control output. The
relay’s contacts must be rated for 12 mA @ 24 Vdc
minimum. Refer to the appropriate wiring diagrams
(attached to the unit control panel for the proper connection
terminals in the unit control panel.
Emergency Stop Input
A binary input is provided on the RTM board for installation
of a field-supplied normally closed (N.C.) switch to use
during emergency situations to shut down all unit
operations. When open, an immediate shutdown occurs.
An emergency stop diagnostic enters the human interface
and the unit will require a manual reset. Refer to the unit
wiring diagrams (attached to the unit control panel for the
proper connection terminals. The switch must be rated for
12 mA @ 24 Vdc minimum. This input will override all VOM
inputs, if the VOM option is on the unit.
VAV Box Option
To interlock VAV box operation with evaporator fan and
heat/cool modes, wire the VAV boxes/air valves to VAV box
control connections on the terminal block.
Supply Duct Static Pressure Control
The RTM relies on input from the duct pressure transducer
when a unit is equipped with VFD to set the supply fan
speed to maintain the supply duct static pressure to within
the static pressure setpoint dead band.
RTM Sensors
RTM sensors include: zone sensors with or without
setpoint inputs and modes, supply air sensor, duct static
pressure, outside air temperature, outside air humidity,
airflow proving, and dirty filter.
Table 32. RTM sensor resistance vs. temperature
Temp °F
Resistance
V ohms
Temp °F
Resistance
V ohms
-40 346.1 71 11.60
-30 241.7 72 11.31
-20 170.1 73 11.03
-10 121.4 74 10.76
-5 103.0 75 10.50
0 87.56 76 10.25
Table 32. RTM sensor resistance vs. temperature
(continued)
Temp °F
Resistance
V ohms
Temp °F
Resistance
V ohms
5 74.65 77 10.00
10 63.8 78 9.76
15 54.66 79 6.53
20 46.94 80 9.30
25 40.40 85 8.25
30 34.85 90 7.33
35 30.18 100 5.82
40 26.22 105 5.21
45 22.85 110 4.66
50 19.96 120 3.76
55 17.47 130 3.05
60 15.33 140 2.50
65 13.49 150 2.05
66 13.15 160 1.69
67 12.82 170 1.40
68 12.50 180 1.17
69 12.19 190 0.985
70 11.89 200 0.830
Table 33. RTM setpoint analog inputs
Cooling or Heating Setpoint
Input, °F (using RTM as zone
temp. source) ohms
Cooling Setpoint Input, °F
(using RTM as supply air
temp. source)
resistance, V
40 40 1084
45 45 992
50 50 899
55 55 796
60 60 695
65 65 597
70 70 500
75 75 403
80 80 305
NA 85 208
NA 90 111
Controls
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