Reznor RXH (Outdoor PreevA) Unit Installation Manual - Manual (Page 45)

Form I-RDH/REH/RHH/RXH (12-14), P/N 215210 R14, Page 45
Each unit has a custom wiring diagram in the control compartment. All optional elec-
trical components ordered with the unit are shown on the wiring diagram. Codes for
options ordered are listed across the bottom of the diagram. To identify option codes,
see list in APPENDIX, page 64.
CAUTION: If any of the original wire as supplied with the appliance
must be replaced, it must be replaced with wiring material having a
temperature rating of at least 105°C, except for sensor lead wires which
must be 150°C. See Hazard Levels, page 2.
7.3 Unit Wiring
Requirements
and Wiring
Diagrams
7.4 Control Wiring The heater is equipped with a low voltage (24V) control circuit. Control wiring con-
nected to a thermostat, a switch, a discharge air temperature sensor, a remote tem-
perature selector or sensor, an amplifier, or the valve must not be run close to or inside
conduit with power or ignition wires.
7.4.1 Control Wiring
Requirements
IMPORTANT (but does not apply to ignition control board used with modulating controls AG58 and D12G): When using
a multimeter to troubleshoot the 24 volt circuit, place the meter’s test leads into the 5 or 9 pin connectors located on the
ignition control board (FIGURE 52, page 58). Do not remove connectors or terminals from the electrical components.
Doing so can result in misinterpreted readings due to the ignition control board’s fault mode monitoring circuits.
TABLE 28 - 24V
Field Control Wiring
Length/Gauge
Total Wire Length Distance from Unit to Control Minimum Recommended Wire Gauge
150ft (46M) 75ft (23M) 18
250ft (76M) 125ft (38M) 16
350ft (107M) 175ft (53M) 14
Digital Control Signal Wiring Recommendations and Requirements
For optimum temperature control performance the manufacturer recommends that the
analog and digital inputs (zone sensors, discharge air sensors, etc.) connected to the
main controller (used in heating/cooling control DG and D12 Options) be routed to the
unit in one of the following manners:
1) In separate conduits, isolated from 24 VAC controls and line voltage power to the
unit, OR
2) If the digital sensor wires are to be run in the same conduit as the 24 VAC control
wiring, the sensor wiring must be completed using shielded cable and bundled
separately from the 24 VAC control wiring. The shield must be drained at the unit
and taped on the opposite end.
See TABLE 29 (left) for digital control sensor wire gauge and length requirements.
TABLE 29 - Maximum Digital
Control Sensor Wire Length for
less than 1°F Signal Error
Wire
Gauge
Maximum Sensor Wire
Length (Digital Control)
AWG Feet Meters
14 800 244
16 500 152
18 310 94
20 200 61
22 124 38
7.4.2 Analog or Digital
Controls
Type of control varies with option selection (identified on the unit wiring diagram). Con-
trol may be analog or digital depending on option selected. Option EG1, EG2, AG1,
AG2, AG3, AG15, AG16, AG58, AG60, AG61, and AG62 controls are analog; Option
DG1, DG2, DG5, DG6, D12B, D12C, D12D, D12E, and D12G controls are digital.
Option AG40 is designed for digital control from a field-supplied source. Optional con-
trols are identified on the wiring diagram supplied with the heater. NOTES: All systems
with reheat Option AU7 have an Option D12 digital control.
Digital Control Systems
have a Programmable
Unit-Mounted Control
and a Room Command
Module
If using a digital control system, the unit is factory equipped with a programmable con-
troller.
Digital control Options DG1, DG2, DG5, and DG6 also include a room command mod-
ule. The type of room command module depends on whether the control system has
a discharge or a room temperature controlled setpoint. A room command module with
an adjustable room temperature setpoint (45°F - 95°F) included with Option DG1 and
DG2 control systems is illustrated in FIGURE 40A, page 46. A room command module
with a discharge air setpoint included with Option DG5 and DG6 control systems is in
FIGURE 40B. The discharge air setpoint can be adjusted ±6°. Discharge temperature
controls may also have an optional room-mounted override sensor.
IMPORTANT: The digital controller inputs are low-current, resistance-based
signals. See special wiring recommendations above for digital sensor wiring.
Digital control Options D12B, D12C, D12D, D12E, and D12G do not include a room
command module. The space temperature sensor module with adjustable setpoint
control and room override illustrated in FIGURE 40C is available as an option.