AAON RSMD2R Quick start guide

RSMD2R
Technical Guide

2RSMD2R Technical Guide
AAON
2425 South Yukon Ave.
Tulsa, OK 74107-2728
www.aaon.com
Factory Technical Support Phone: [phone]
AAON®Controls Support: 866-918-1100
It is the intent of AAON®to provide accurate and current
product information. However, in the interest of product
improvement, AAON®reserves the right to change pricing,
specications, and/or design of its product without notice,
obligation, or liability.
AAON Part Number: G088350, Rev. D
Copyright February 2024 AAON, Inc.
AAON®is a registered trademark of AAON, Inc., Tulsa, OK.
AAON®assumes no responsibility for errors or omissions in
this document.
This document is subject to change without notice.
RSMD2R REVISION LOG
REVISION & DATE CHANGE
Rev. A, March 15, 2021 Original
Rev. B, December 18, 2023 Added Condenser Fan Cleaning to Sequence, cosmetic updates
Rev. C, January 19, 2024 Updated Dehumidication Sequence
Rev. D, February 2, 2024 Added WSHP Valve Control to Sequence
www.aaon.com
RSMD2R PARTS REFERENCE
PART DESCRIPTION PART NUMBER
Refrigerant System Module for Digital Compressors ( RSMD2R) ASM02869
VCCX-IP Controller ASM07424
VCCX2 Controller ASM01698
Prism 2 ASM02533
IP Module Kit ASM01902
CommLink 5 ASM01874
EBC E-BUS Cable Assembly E-BUS Power & Comm
1.5 Ft, 3 Ft, 10 Ft, 25 Ft, 50 Ft, 75 Ft,
100 Ft, 150 Ft, 250 Ft, and 1000 Foot Spool
G029440 (1.5 Ft), G012870 (3 Ft), G029460 (10 Ft), G045270 (25
Ft), G029510 (50 Ft), G029530 (75 Ft), G029450 (100 Ft), G029470
(150 Ft), V36590 (250 Ft), G018870 (SPOOL)
Modular Service Tool SD - Operator Interface ASM01895
All manuals are also available for download from
www.aaon.com/controlsmanuals.

3RSMD2R Technical Guide
TABLE OF CONTENTS
OVERVIEW ................................................................................................................................................. 5
RSMD2R Overview................................................................................................................................................. 5
Dimensions ............................................................................................................................................................. 6
INSTALLATION AND WIRING.................................................................................................................. 7
Electrical Environmental Requirements .................................................................................................................. 7
WIRING ....................................................................................................................................................... 8
Inputs ...................................................................................................................................................................... 8
Outputs ................................................................................................................................................................... 9
INPUTS AND OUTPUTS ......................................................................................................................... 10
Inputs/Outputs Map............................................................................................................................................... 10
Input and Output Descriptions ...............................................................................................................................11
SEQUENCE OF OPERATIONS .............................................................................................................. 12
Cooling Mode, Dehumidication, and Head Pressure Control.............................................................................. 12
LCD SCREENS ........................................................................................................................................ 13
LCD Display Screen and Navigation Keys............................................................................................................ 13
Screen Map........................................................................................................................................................... 14
Screen Descriptions.............................................................................................................................................. 15
Protected Screen Map .......................................................................................................................................... 19
Protected Screen Descriptions ............................................................................................................................. 20
TROUBLESHOOTING ............................................................................................................................. 23
LED Diagnostics ................................................................................................................................................... 23
Suction Pressure Transducer Testing ................................................................................................................... 24
Copeland®Discharge Thermistor Temperature Sensor Testing............................................................................ 25
Temperature Sensor Testing ................................................................................................................................. 26
Head Pressure Transducer ................................................................................................................................... 27
APPENDIX A: CONDENSER OPTIONS ................................................................................................ 28
Default: Two Condenser Operation....................................................................................................................... 28
Single Condenser Per Module .............................................................................................................................. 30
Single Condenser Per Two Modules..................................................................................................................... 32
Single Condenser for Three Modules ................................................................................................................... 34
Two Condensers Per Two Modules ...................................................................................................................... 36
ON/OFF Condenser Options ................................................................................................................................ 39

4RSMD2R Technical Guide
FIGURES AND TABLES
TABLES
Table 1: RSMD2R Controller Electrical and Environmental Requirements .....................................................................7
Table 2: RSMD2R Inputs and Outputs ..............................................................................................................................10
Table 3: Navigation Key Functions.......................................................................................................................................13
Table 4: Main Screens............................................................................................................................................................15
Table 5: Module Screens .......................................................................................................................................................15
Table 6: System Status Screens...........................................................................................................................................16
Table 7: Sensor Status Screens ...........................................................................................................................................16
Table 8: Alarms Screens ........................................................................................................................................................17
Table 9: Alarm History Screens.............................................................................................................................................18
Table 10: Setpoint Status Screens .........................................................................................................................................18
Table 11: Conguration Screens.............................................................................................................................................20
Table 12: Diagnostic Screens..................................................................................................................................................21
Table 13: Coil Pressure/Voltage/Temp for Suction Pressure Transducers - R410-A Refrigerant.................................24
Table 14: Discharge Thermistor Temperature/Resistance..................................................................................................25
Table 15: 0-5V Temperature Sensor - Voltage & Resistance for Type III Sensors .........................................................26
Table 16: Head Pressure Transducer Chart..........................................................................................................................27
FIGURES
Figure 1: RSMD2R Dimensions ..............................................................................................................................................6
Figure 2: RSMD2R Inputs Wiring.............................................................................................................................................8
Figure 3: RSMD2R Outputs Wiring .........................................................................................................................................9
Figure 4: LCD Display and Navigation Keys........................................................................................................................13
Figure 5: RSMD2R LED Locations........................................................................................................................................23
Figure 6: Default: Two Condenser RSMD2R Module Wiring ............................................................................................28
Figure 7: Prism 2 Condenser Conguration: Default Two Condenser Operations ........................................................29
Figure 8: Single Condenser Per RSMD2R Module Wiring ................................................................................................30
Figure 9: Prism 2 Condenser Conguration: Single Condenser Per Module .................................................................31
Figure 10: Single Condenser Per Two RSMD2R Modules Wiring......................................................................................32
Figure 11: Prism 2 Condenser Conguration: Single Condenser Per Two Modules.......................................................33
Figure 12: Single Condenser for Three RSMD2R Modules Wiring ....................................................................................34
Figure 13: Prism 2 Condenser Conguration: Single Condenser for Three Modules .....................................................35
Figure 14: A1/B1 Wiring.............................................................................................................................................................36
Figure 15: A2/B2 Wiring.............................................................................................................................................................37
Figure 16: Prism 2 Condenser Conguration: A1/B1 and A2/B2 Condenser Conguration...........................................38
Figure 17: Prism 2 Condenser Conguration: ON/OFF Condenser Options....................................................................39

5RSMD2R Technical Guide
OVERVIEW
RSMD2R Overview
Features & Applications
The Refrigerant System Module for Digital Compressors (RSMD2R)
can monitor and control up to two compressors and condensers. The
compressors can only be in a non-tandem conguration. The module
is designed for R410-A refrigerant.
NOTE: The RSMD2R is for units that match
all of the following criteria:
1. Two circuits, single compressor per circuit.
2. Compressors may be any mix of xed, two-step,
and digital.
3. Reheat is present on the second circuit only.
The RSMD2R is connected to the VCCX2 Controller. Up to four
RSMD2R’s can be connected, depending on the size of the system.
There are two E-BUS Expansion Ports which allow the use of
communicating sensors and the E-BUS Modules.
The RSMD2R provides three analog inputs, four binary inputs,
ve relays, and two analog outputs. See Figures 2 & 3, pages 8
& 9 for wiring.
The RSMD2R Module provides the following:
• Modulates the Compressors to satisfy the Suction Coil
(Saturated) Temperature. The Suction Coil (Saturated)
Temperature Setpoint is reset by the VCCX2 Controller
to maintain the Supply Air Temperature during Cooling
mode. During Dehumidication mode, it controls the
Compressors to the Suction (Saturation) Temperature
Setpoint.
• In Heat Pump Heating mode, the RSMD2R modulates
and stages the compressors to maintain a given Supply
Air Temperature Setpoint.
• Modulates the Condenser Fan or Valve to maintain the
Head Pressure Setpoint.
• Provides alarms and safeties for the Compressor and
Condenser operation.
• Allows connection of the Modular Service Tool SD to the
module when required communication wire is run to the
VCCX2 Controller.
• Provides a 2 x 8 LCD character display and four buttons
that allow for status of system operation, system setpoints,
system congurations, sensors, and alarms, and to change
the module’s address, if necessary.

6RSMD2R Technical Guide
OVERVIEW
Dimensions
Figure 1: RSMD2R Dimensions
10A250VAC ~
5A30VDC
SA
VDE
G5Q-1A4
OMRON
DC12V
CHINA
1.33 1.50
1.50
0.45
6.15
3.09
3.07
4.96
5.26
5.55
0.75 4.10 0.74
5.05
1.50
0.52
1.33
1.50
ALARM
UP
DOWN
ENTERMENU
AAON P/N: ASM02869
+24 VAC
GND
RELAY CONTACT
RATING IS 1 AMP
MAX @ 24 VAC
CONDENSER 1
COMP 1
COMP 2
ANALOG OUT
REVERSING VALV E
COMMON
RELAYOUTPUT
TERMINALS
LABEL P/N:
G088060
COND 1
COND 2
GND
24 VAC
POWER ONLY
WARNING!
POLARITY
MUST BE
OBSERVED
OR THE
CONTROLLER
WILL BE
DAMAGED
CONDENSER 2
HEAD PRES 1
+5 V
+5 V
COMP DIS 1
COMP 1
SP-1
HP-1
COMP DIS 2
COMP 2
GND
GND
OA COIL / POWF
EMER SHDN
GND
LEAVING H20
GND
SUCTION PRES 2
HEAD PRES 2
+5 V
+5 V
SP-2
HP-2
GND
GND
R+
SHD
T-
E-BUS
R+ SHD T-
DUAL E-BUS
EXPANSION
RSMD2R
www.aaon.com
SUCTION PRES 1

7RSMD2R Technical Guide
INSTALLATION AND WIRING
Electrical Environmental Requirements
General
Correct wiring of the main unit controller and its modules is the most
important factor in the overall success of the controller installation
process. The main unit controller and modules are factory installed
and wired at the AAON factory. Some of the following information
may not apply to your installation if it 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.
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, RSMD2R, and any associated
module.
Please carefully read and apply the following information when
wiring the unit controller, RSMD2R, and any associated module.
1. All wiring is to be in accordance with local and national
electrical codes and specications.
2. 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.
3. Minimum wire size for 24 VAC wiring should be
18-gauge.
4. Minimum wire size for all sensors should be 24-gauge.
Some sensors require two-conductor wire and some
require three-or four-conductor wire.
5. Minimum wire size for 24 VAC thermostat wiring should
be 22-gauge.
6. 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.
7. When communication wiring is to be 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 specication 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.
8. Before applying power to the HVAC Unit Controller,
RSMD2Rs, 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.
Control
Device
Voltage
VA Load
Operating
Temperature
Humidity
(Non-
Condensing)
RSMD2R
Controller
18-30VAC 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: RSMD2R Controller Electrical and
Environmental Requirements

8RSMD2R Technical Guide
WIRING
Inputs
RSMD2R Wiring
The RSMD2R monitors and controls one refrigeration circuit of
the HVAC unit. The module is designed for R410-A refrigerant.
The RSMD2R is connected to the VCCX2 Controller. Up to four
RSMD2R’s can be connected, depending on the size of the system.
There are two E-BUS Expansion Ports which allow the use of
communicating sensors and the E-BUS Modules.
The RSMD2R provides three analog inputs, four binary inputs, ve
relays, and two analog outputs. See Figure 2, this page for inputs
wiring and Figure 3, page 9 for outputs wiring.
Suction Pressure Sensor Wiring
The Suction Pressure Transducers must be wired as shown in Figure
2, this page. It is typically required for all VCCX2 applications.
The Suction Pressure Sensors are used to measure suction pressure
at the HVAC unit’s DX evaporator coil suction line. This suction
line pressure is converted to saturated refrigerant temperature.
The saturated refrigerant temperature is used to properly control
the compressors to maintain a given Suction Coil (Saturated)
Temperature Setpoint. In Cooling mode, the VCCX2 resets the
Suction Coil (Saturated) Temperature Setpoint to maintain a given
Supply Air Temperature Setpoint. In Dehumidication Mode, the
Suction Coil (Saturated) Temperature Setpoint is a user congurable
setpoint that can be reset based on indoor humidity levels.
WARNING: Observe Polarity! All boards must be wired
with GND-to-GND and 24-VAC-to-24
VAC. Failure to observe polarity will result
in damage to one or more of the boards.
Expansion modules must be wired in such
a way that the expansion modules and the
controller are always powered together. Loss
of power to the expansion module will cause
the controller to become inoperative until
power is restored to the expansion module.
Figure 2: RSMD2R Inputs Wiring
GND18-30
VAC
Head Pressure 2 Sensor
(by others)
Comp. Discharge
Temp 1 Sensor
Comp. Discharge
Temp 2 Sensor
Leaving Water
Temp Sensor
Comp Status 1
Comp Status 2
Outside Coil Temp/POWF
Emergency Shutdown
TEMP1
TEMP2
TEMP3
GND
GND
BIN4
BIN3
BIN2
BIN1
HP
+V
Suction Pressure 1
Sensor GND
+V
SP
RD
WT
BL
Head Pressure 1 Sensor
(by others) GND
HP
+V
RD
WT
BL
Suction Pressure 2
Sensor GND
+V
SP
RD
WT
BL
RD
WT
BL
Line Voltage
Size transformer for
correct total load.
RSMD2R = 18 VA
GND
10A250VAC ~
5A30VDC
SA
VDE
G5Q-1A4
OMRON
DC12V
CHINA
ALARM
UP
DOWN
ENTERMENU
AAON P/N: ASM02869
+24 VAC
GND
RELAYCONTACT
RATING IS 1 AMP
MAX @ 24 VAC
CONDENSER 1
COMP 1
COMP2
ANALOG OUT
REVERSING VALVE
COMMON
RELAY OUTPUT
TERMINALS
LABEL P/N:
G088060
COND 1
COND 2
GND
24 VAC
POWER ONLY
WARNING!
POLARITY
MUST BE
OBSERVED
OR THE
CONTROLLER
WILL BE
DAMAGED
CONDENSER 2
HEAD PRES 1
+5 V
+5 V
COMP DIS 1
COMP1
SP-1
HP-1
COMP DIS 2
COMP2
GND
GND
OA COIL / POWF
EMER SHDN
GND
LEAVING H20
GND
SUCTION PRES 2
HEAD PRES 2
+5 V
+5 V
SP-2
HP-2
GND
GND
R+
SHD
T-
E-BUS
R+ SHD T-
DUAL E-BUS
EXPANSION
RSMD2R
www.aaon.com
SUCTION PRES 1

9RSMD2R Technical Guide
WIRING
Outputs
Head Pressure Control
The Head Pressure Transducers are used to measure Head Pressure at
the discharge line. This Head Pressure is used to drive the Condenser
Fans with a 0-10 VDC output signal or valve with a 2-10 VDC output
signal to maintain a given Head Pressure Setpoint.
Compressor Discharge Sensors
The Digital Compressor Discharge Temperature Sensor monitors
the discharge temperature from the Digital Compressor to protect
against overheating.
Leaving Water Temperature Sensor
The Leaving Water Temperature Sensor is used to measure the
Leaving Water Temperature when used on a WSHP unit.
CAUTION: The Shraeder port used for installation of the
suction pressure transducer should be located in
a vertical position of the suction line to prevent
refrigerant oil from accumulating in the sensor.
NOTE: If there are two compressors on a single circuit (a
tandem circuit), Suction Pressure 2, Head Pressure
2, and Condenser Signal 2 would not be used.
Figure 3: RSMD2R Outputs Wiring
GND18-30
VAC
Line Voltage
Size transformer for
correct total load.
RSMD2R = 18 VA
10A250VAC ~
5A30VDC
SA
VDE
G5Q-1A4
OMRON
DC12V
CHINA
ALARM
UP
DOWN
ENTERMENU
AAON P/N: ASM02869
+24 VAC
GND
RELAY CONTACT
RATING IS 1 AMP
MAX @ 24 VAC
CONDENSER 1
COMP 1
COMP 2
ANALOG OUT
REVERSING VALVE
COMMON
RELAY OUTPUT
TERMINALS
LABEL P/N:
G088060
COND 1
COND 2
GND
24 VAC
POWER ONLY
WARNING!
POLARITY
MUST BE
OBSERVED
OR THE
CONTROLLER
WILL BE
DAMAGED
CONDENSER 2
HEAD PRES 1
+5 V
+5 V
COMP DIS 1
COMP 1
SP-1
HP-1
COMP DIS 2
COMP 2
GND
GND
OA COIL / POWF
EMER SHDN
GND
LEAVING H20
GND
SUCTION PRES 2
HEAD PRES 2
+5 V
+5 V
SP-2
HP-2
GND
GND
R+
SHD
T-
E-BUS
R+ SHD T-
DUAL E-BUS
EXPANSION
RSMD2R
www.aaon.com
SUCTION PRES 1
Belimo actuator wiring
shown. Consult factory for
other manufacturer wiring
instructions.
Note:
All relay outputs are normally open
and rated for 24 VAC power only.
1 Amp maximum load.
24 VAC ONLY
COMPRESSOR 1 ENABLE
COMPRESSOR 2 ENABLE
CONDENSER 1 ENABLE
CONDENSER 2 ENABLE
REVERSING VALVE
Digital Compressor 1
Digital Compressor 2
Condenser
Signal 1
Condenser
Signal 2
WSE Bypass
Valve Actuator
RLY2
RLY1
RLY4
RLY3
RLY5
COMM
UNLOAD
24 VAC
UNLOAD
AOUT1
GND
AOUT2
Connects to VCCX2
Loop Communications
connector when used on
a split system.
GND
+
GND
+
COM
+
COM
+
1 COM
2 +
3Y1

10RSMD2R Technical Guide
INPUTS AND OUTPUTS
Inputs/Outputs Map
Table 2: RSMD2R Inputs and Outputs
REFRIGERATION SYSTEM MODULE
FOR DIGITAL COMPRESSORS
Analog Inputs
1Suction Pressure 1 Sensor (SP-1)
2Head Pressure 1 Sensor (HP-1)
3Suction Pressure 2 Sensor (SP-2)
4Head Pressure 2 Sensor (HP-2)
5Compressor Discharge Temperature Sensor 1 (TEMP1)
6Compressor Discharge Temperature Sensor 2 (TEMP2)
7Leaving Water Temperature Sensor (TEMP3)
Binary Inputs
1Compressor Status 1 (BIN1)
2Compressor Status 2 (BIN2)
3Outside Coil Temperature / Proof of Water Flow (BIN3)
4Emergency Shutdown (BIN4)
Analog Outputs (0-10 VDC)
1Condenser 1 Fan Signal (AOUT1)
2Condenser 2 Fan Signal (0-10 VDC) or WSE Bypass Actuator
(2-10 VDC) (AOUT2)
Relay Outputs (24 VAC)
1Compressor 1 Enable Relay (RLY1)
2Compressor 2 Enable Relay (RLY2)
3Condenser 1 Enable Relay (RLY3)
4Condenser 1 Enable Relay (RLY4)
5Reversing Valve Relay (RLY5)