AAON RSMD2R Technical Manual Download Page 7

7

RSMD2R Technical Guide 

INSTALLATION AND WIRING

Electrical and 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 -22ºF  

(-30ºC),  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 specifications.

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 specification 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 first 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

-22°F to 158°F

-30ºC 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

Summary of Contents for RSMD2R

Page 1: ...RSMD2R Technical Guide...

Page 2: ...sions in this document This document is subject to change without notice RSMD2R REVISION LOG REVISION DATE CHANGE Rev A March 15 2021 Original www aaon com RSMD2R PARTS REFERENCE PART DESCRIPTION PART...

Page 3: ...odule Screens 14 System Status Screens 15 Sensor Status Screens 16 Setpoint Status Screens 17 Alarms Screens 18 Alarm History and Protected Screens 20 Configuration and Diagnostic Screens 21 Diagnosti...

Page 4: ...ion Keys 13 Figure 5 RSMD2R LED Locations 24 Figure 6 Default Two Condenser RSMD2R Module Wiring 29 Figure 7 Prism 2 Condenser Configuration Default Two Condenser Operations 30 Figure 8 Single Condens...

Page 5: ...o 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 Te...

Page 6: ...TING 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 T...

Page 7: ...ll 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 a...

Page 8: ...door 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 mod...

Page 9: ...Line Voltage Size transformer for correct total load RSMD2R 18 VA 10A250VAC 5A30VDC SA VDE G5Q 1A4 OMRON DC12V CHINA ALARM UP DOWN ENTER MENU AAON P N ASM02869 24 VAC GND RELAY CONTACT RATING IS 1 AM...

Page 10: ...essor Discharge Temperature Sensor 1 TEMP1 6 Compressor Discharge Temperature Sensor 2 TEMP2 7 Leaving Water Temperature Sensor TEMP3 Binary Inputs 1 Compressor Status 1 BIN1 2 Compressor Status 2 BIN...

Page 11: ...Status 2 When this wet contact input closes a 24 volt signal to Binary Input 2 indicates that Compressor 2 is running Typically the source for this is relay output 2 If Binary Input 2 opens Compressor...

Page 12: ...re to temperature For Copeland Digital Scroll Compressor units the RSMD2R will modulate the Copeland Digital Scroll Compressor to maintain the Evaporator Coil Suction Saturation Temperature Setpoint a...

Page 13: ...escriptions Navigation Key Key Function MENU Use the MENU key to move through screens within Main Menu categories and return to the Main Menu while at other screens UP Use this key to adjust setpoints...

Page 14: ...reens Press to go to SENSOR STATUS screens SENSOR STATUS Press to scroll through SENSOR STATUS screens Press to go to ALARMS screens ALARMS Press to scroll through ALARMS screens Press to go to ALARM...

Page 15: ...re OFF COOL HEAT DEHUMID FORCE COMP A1 B1 OFF MODULATING COMPRESSOR A1 B1 based on board address OFF MOD POSITION OFF Compressor is off MODULATING PERCENTAGE 0 100 COMP A2 B2 ON OFF COMPRESSOR A2 B2 b...

Page 16: ...1 READING FROM INPUT HEAD PR1 XXX PSI HEAD PRESSURE 1 READING FROM INPUT SUCTION 2 XXX PSI SUCTION PRESSURE 2 READING FROM INPUT HEAD PR2 XXX PSI HEAD PRESSURE 2 READING FROM INPUT CALC CT1 XX DEG CAL...

Page 17: ...SSURE SETPOINT STATUS Valid range is 275 to 475 PSI Default is 340 PSI IF CONFIGURED FOR FAN CYCLE THE FOLLOWING TWO SCREENS WILL DISPLAY FAN ON XX PSI HEAD PRESSURE HEADING WHEN FAN CYCLE IS ON FAN O...

Page 18: ...Power must be cycled to clear the alarm LOW SUCTION PRESSURE 2 SP2 FAILURE This alarm will occur if Suction Pressure 2 stays below the low suction pressure setpoint for one minute or falls below 40 ps...

Page 19: ...r and there is no Proof of Flow Input Enable for more than three minutes or if during Heat Pump heating the Proof of Flow Enable is open for more than two seconds This alarm will disable when Proof of...

Page 20: ...S screen section NOTE The screen will display minutes for the first 60 minutes of alarm occurrence hours for the next 72 hours of alarm occurrence and days for the next 30 days of alarm occurrence Aft...

Page 21: ...h the screens DIAGNSTC WDOG CNT WATCHDOG TIMER Displays the numbers of times the board has been reset due to watchdog timer overview POWR CNT POWER LOSS COUNT Displays the numbers of times the board h...

Page 22: ...DE Displays the current status of Force Mode Values are ON OFF IF FORCE MODE IS ON THE FOLLOWING SCREENS WILL APPEAR RLY 1 5 ON OFF RELAYS 1 5 FORCE MODE Press the UP or DOWN buttons to select ON or O...

Page 23: ...e only way to clear these alarm counts is by using Prism 2 and selecting Select Alarms to Delete from the ALARM button menu See Alarm Polling in the Prism 2 Technical Guide for more information Addres...

Page 24: ...l display on the LCD display TheALARM LED also blinks when the expansion valve is initializing at startup COMM Every time the module receives a valid E BUS request from the VCCX2 Controller this LED w...

Page 25: ...ropriate chart depending on the refrigerant you are using If the temperature voltage or pressure voltage readings do not align closely with the chart your Suction Pressure Transducer is probably defec...

Page 26: ...plus lead on the sensor input terminal being investigated If the voltage is above 4 98 VDC then the sensor or wiring is open If the voltage is less than 0 38 VDC then the sensor or wiring is shorted D...

Page 27: ...follow the notes and instructions that appear after the chart when checking sensors Table 6 0 5V Temperature Sensor Voltage Resistance for Type III Sensors Temperature Resistance Voltage for Type III...

Page 28: ...terminal See Table 7 this page Head Pressure Transducer Chart Voltage Pressure Voltage Pressure 0 5 0 2 6 350 0 6 17 2 7 367 0 7 33 2 8 384 0 8 50 2 9 400 0 9 67 3 0 417 1 0 83 3 1 434 1 1 100 3 2 450...

Page 29: ...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 G...

Page 30: ...ons RSMD2R Main Configuration Screen 2 Condenser Options Select the 2 Condensers per RSMD2R option on the above Hand Held Service Tool Screen HVAC Unit Application The Two Condenser per RSMD2R configu...

Page 31: ...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 Note All relay outputs are normally open and...

Page 32: ...2 Condenser Options Select the 1 Condenser for 1 RSMD2R option on the above Hand Held Service Tool Screen HVAC Unit Application The Single Condenser for One RSMD2R configuration is used with the foll...

Page 33: ...EXPANSION RSMD2R www aaon com SUCTION PRES 1 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...

Page 34: ...dules RSMD2R Main Configuration Screen 2 Condenser Options Select the 1 Condenser for 2 RSMD2Rs option on the above Hand Held Service Tool Screen HVAC Unit Application The Single Condenser for Two RSM...

Page 35: ...aon com SUCTION PRES 1 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 EN...

Page 36: ...ree Modules RSMD2R Main Configuration Screen 2 Condenser Options Select the 1 Condenser for 3 RSMD2Rs option on the above Hand Held Service Tool Screen HVAC Unit Application The One Condenser for Thre...

Page 37: ...D 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 SH...

Page 38: ...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 S...

Page 39: ...Main Configuration Screen 2 Condenser Options Select the 2 Condensers for 2 RSMD2Rs option on the above Hand Held Service Tool Screen HVAC Unit Application The Two Condensers per Two RSMD2Rs configur...

Page 40: ...n to have the Condenser Fan turn On Off with the Compressors This can also be selected when No Head Pressure Control is required Select this option if the Condenser Fan cycles On Off based on the Fan...

Page 41: ...41 RSMD2R Technical Guide NOTES...

Page 42: ...15 AAON Factory Technical Support 918 382 6450 techsupport aaon com AAON Controls Support 866 918 1100 Monday through Friday 7 00 AM to 5 00 PM Central Standard Time Controls Support website www aaon...

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