7RSMD Technical Guide
WIRING
Electrical and Environmental Requirements
General
Correct wiring of the AAON unit controller and its modules is
the most important factor in the overall success of the installation
process. TheAAON unit controller and modules are factory installed
and wired at the AAON factory. Some of the following information
may not apply if unit was pre-wired at the factory. However, if
troubleshooting of the controller or modules is required, it is a good
idea to be familiar with the system wiring.
Wiring
The modules must be connected to an 18-30 VAC power source
of the proper size for the calculated VA load requirements. All
transformer sizing should be based on the VA ratings listed in Table
1, this page.
ELECTRICAL AND ENVIRONMENTAL
REQUIREMENTS
Control
Device
Voltage
VA Load
Operating
Temperature
Humidity
(Non-
Condensing)
RSMD
Module
18-30 VAC 18 -4°F to 158°F
(-20ºC to 70ºC) 0-95% RH
Inputs
Resistive Inputs require 10KΩ
Type 3 Thermistor
24VAC Inputs provide 4.7kΩ Load
Outputs Relay Outputs: 1 Amp
maximum per output.
Table 1: Electrical and Environmental Requirements
NOTE: If the temperature at the controller is below -4ºF
(-20ºC), the display refresh rate could be less
responsive.
WARNING: When using a single transformer to power
more than one controller or expansion
module, the correct polarity must always be
maintained between the boards. Failure to
observe correct polarity will result in damage
to the unit controller, RSMD, and any associated
module.
Please carefully read and apply the following information when
wiring the unit controller, RSMD, and any associated module.
• All wiring is to be in accordance with local and national
electrical codes and specications.
• All 24 VAC wiring must be connected so that all ground
wires remain common. Failure to follow this procedure can
result in damage to the controller and connected devices.
• Minimum wire size for 24 VAC wiring should be 18-gauge.
• Minimum wire size for all sensors should be 24-gauge.
Some sensors require two-conductor wire and some require
three-or four-conductor wire.
• Minimum wire size for 24 VAC thermostat wiring should
be 22-gauge.
• Be sure that all wiring connections are properly inserted
and tightened into the terminal blocks. Do not allow wire
strands to stick out and touch adjoining terminals which
could potentially cause a short circuit.
• When communication wiring is used to interconnect
HVAC unit controllers together or to connect to other
communication devices, all wiring must be plenum-rated,
minimum 18-gauge, two-conductor, twisted pair with
shield. AAON can supply communication wire that meets
this specication and is color coded for the network or
local loop. Please consult your AAON distributor for
information. If desired, Belden #82760 or equivalent wire
may also be used.
• Before applying power to the HVAC unit controller, RSMD
Modules, and any associated modules, be sure to recheck
all wiring connections and terminations thoroughly.
Powering Up
When the controller and modules are rst powered up, the POWER
LED should light up and stay on continuously. If it does not light up,
check to be sure that you have 24 VAC connected to the controller,
that the wiring connections are tight, and that they are wired for
the correct polarity. The 24 VAC power must be connected so that
all ground wires remain common. If after making all these checks,
the POWER LED does not light up, please contact AAON Controls
Support for assistance.
