AAON RSMV-HP Technical Manual Download Page 10

Zone

Zone

SEQUENCE OF OPERATIONS

                    

RSMV-HP Technical Guide

10

Cooling Mode 

In the Cooling Mode, as the Supply Air Temperature (SAT) rises 
above the Active SAT Cooling Setpoint, the compressors will stage 
on and modulate to maintain the Active Evaporator Coil Suction 
(Saturated)  Temperature Setpoint.  One set of tandem compressors 
(a VFD compressor and a fi xed stage compressor) are controlled per 
Refrigerant System Module-VFD Compressor (RSMV).  Multiple 
RSMVs are needed for multiple sets of tandem compressors

In units with one set of tandem compressors, if the VFD compressor 
modulates  to  100%  and  the  SAT  is  still  above  the  SAT  Cooling 
Setpoint for the Cooling Stage Up Delay, then the fi xed compressor 
will stage on.  The VFD compressor will then be allowed to modulate 
as  necessary  to  maintain  the Active  Evaporator  Coil  Suction 
(Saturated)  Temperature Setpoint.  Minimum off  times must also 
be met before compressors can stage on.

To  stage  down  compressors,  if  the  VFD  compressor(s)  have 
modulated down to 30% for the Stage Down Delay period and the 
SAT has fallen below the SAT Cooling Setpoint minus the Stage 
Control Window, then the last compressor to have staged on (VFD 
or Fixed) will stage off  – assuming its Minimum Run Time has been 
met.  Any remaining VFD compressors are then allowed to modulate 
as needed.  If the last remaining VFD compressor reaches 0% for 
the Stage Down Delay, it will stage off .

Dehumidi

fi

 cation Operation

Once in Dehumidifi cation Mode, units with fi xed compressors will 
activate the compressors to maintain the Evaporator Coil Suction 
(Saturated)    Temperature  Setpoint.   An  RSMV  Module  will  be 
required  for  each  fixed  compressor  or  each  fixed  compressor 
tandem pair in order to monitor the suction (saturated) temperature 
and  control  the  compressor(s)  accordingly.  Each  RSMV  will 
independently activate and stage its compressor(s) to maintain that 
circuit’s Suction (Saturated) Temperature Setpoint.  The staging of 
compressors on an RSMV is subject to Stage Up and Stage Down 
Delays as well as compressor Minimum Run Times and Minimum 
Off  Times.

A  suction  pressure  transducer  is  used  and  the VCC-X  / VCCX2 
Controller converts that to a Suction (Saturated) Temperature value

On units with one or more sets of VFD/Fixed tandem compressors, 
each set of tandem compressors (one circuit) will be controlled by 
a separate RSMV Module with its own Suction Pressure Transducer 
(converted  to  a  Suction  (Saturated) Temperature).  Once  the  unit 
enters the Dehumidifi cation Mode, each RSMV will initially activate 
the VFD compressor as required to maintain the Suction (Saturated) 
Temperature Setpoint. At that point each RSMV will modulate its 
VFD  compressor  and  enable  the  fi xed  compressor,  as  necessary, 
to maintain the Suction (Saturated) Temperature Setpoint for that 
circuit. 

If the VFD compressor reaches 100% for the Stage Up Delay and 
the Suction (Saturated) Temperature is still above setpoint, then the 
fi xed compressor will stage on while the VFD compressor modulates 
as needed.   If the VFD compressor has modulated down to 0% and 
the Suction (Saturated) Temperature is 5 degrees below the Suction 
(Saturated) Temperature for the Stage Down Delay period, the fi xed 
compressor will stage off  and the VFD compressor will continue to 
modulate. During this operation, compressor Minimum Run Times 
and Minimum Off  Times must be met.

SAFETY:

   If the Coil Temperature drops below 32˚F, any 

  cooling remaining on will be forced to stage off .

Electronic Expansion Valve (EXV) 

Operation

If EXV’s are being used, a Coil (Suction Line) Temperature Sensor 
will  measure  the  Coil  (Suction  Line)  Temperature  after  each 
Evaporator Coil line for each compressor, and this sensor will be 
connected to an RSMV-HP Module. This temperature will be used 
in conjunction with the calculated saturated refrigerant temperature 
to  calculate  the  Superheat  of  each  evaporator  coil. The  EXV  for 
each coil will then be controlled to maintain the Superheat Setpoint. 

Head Pressure Control

The Refrigeration System Module for VFD Heat-Pump Compressors 
(RSMV-HP) can monitor a Head Pressure Transducer and control a 
Condenser Fan to maintain a Head Pressure Setpoint.  The RSMV-HP 
must be confi gured for an Air Cooled Condenser.

A Condenser Relay is commanded on when the fi rst compressor is 
enabled (except if the unit is in Heat Pump Defrost Mode). On an 
Air Cooled Unit, the Condenser Fan will be controlled with 0-10 
VDC output signal or a PWM output signal.  Both outputs operate 
simultaneously. 

When the Condenser Signal fi rst activates, it maintains at 100% for 
10 seconds.

In the Cooling Mode, the Condenser Signal will modulate to maintain 
the  Cooling  Head  Pressure  Setpoint.  The  signal  can  modulate 
between 15% and 100%.  If the Head Pressure exceeds 550 PSIG, 
the condenser control signal will immediately go to 100% and a High 
Head Pressure Alarm will be generated.  The alarm will be deactivated 
when the Head Pressure drops below 540 PSIG.

In the Dehumidifi cation Mode, the Condenser Output Signal controls 
to the Reheat Head Pressure Setpoint.  High Head Pressure conditions 
produce the same eff ects as in the Cooling Mode.

If no Head Pressure Sensor is detected, the Condenser the Condenser 
Output Signal will be maintained at 100%.

Cooling Mode, EXV Operation & Head Pressure Control 

Summary of Contents for RSMV-HP

Page 1: ...RSMV HP Technical Guide ...

Page 2: ... 10 Superheat Control 11 Heat Pump Standard Defrost Operation 11 Heat Pump Adaptive Defrost Operation 11 AAON WattMaster Controls Inc 8500 NW River Park Drive Parkville MO 64152 Toll Free Phone 866 918 1100 PH 816 505 1100 FAX 816 505 1101 E mail mail wattmaster com Visit our web site at www orioncontrols com WattMaster Form AA RSMVHP TGD 01C Copyright April 2018 WattMaster Controls Inc AAON Part ...

Page 3: ...tory Screen 17 Protected Screens Map 17 Diagnostics Screens 18 Alarm Counts Screen 19 Address Screen 19 TROUBLESHOOTING 20 LED Diagnostics 20 Suction Pressure Transducer Testing 21 Coil Temperature Sensor Testing 22 Head Pressure Transducer Chart 23 APPENDIX SYSTEM CONFIGURATION USING PRISM 2 24 One Condenser Per RSMV 24 One Condenser Per 2 RSMVs 25 One Condenser For 3 RSMVs 26 One Condenser For 4...

Page 4: ...6 7 for wiring The RSMV HP Module provides the following Modulates the Compressors to satisfy the Suction Coil Saturated Temperature The Suction Coil Satu rated Temperature Setpoint is reset by the VCC X VCCX2 Controller to maintain the Supply Air Tem perature during Cooling Mode During Dehumidifi cation Mode it controls the Compressors to the Suction Saturation Temperature Setpoint Modulates the C...

Page 5: ...URE SENSOR COIL TEMP SENSORS BINARY INPUTS ANALOG OUTPUTS BLACK 5 V 5 V COIL TEMP 1 COMP STATUS 1 BLACK COMP SIGNAL CONDENSER VALVE WHITE SP HP COIL TEMP 2 COMP 2 STATUS GND GND COIL TEMP 3 OUTSIDE COIL TEMP POWF NOT USED COIL TEMP 4 GND WHITE RED RED GND GREEN GREEN REVERSING VALVE COMMON RELAY OUTPUT TERMINALS www aaon com WattMaster Overlay 000071 Rev1C SW EXP VLV 4 BLACK BLACK WHITE WHITE RED ...

Page 6: ...DENSER COMP 1 COMP 2 SUCTION PRESSURE SENSOR HEAD PRESSURE SENSOR COIL TEMP SENSORS BINARY INPUTS ANALOG OUTPUTS BLACK 5 V 5 V COIL TEMP 1 COMP STATUS 1 BLACK COMP SIGNAL CONDENSER VALVE WHITE SP HP COIL TEMP 2 COMP 2 STATUS GND GND COIL TEMP 3 OUTSIDE COIL TEMP POWF NOT USED COIL TEMP 4 GND WHITE RED RED GND GREEN GREEN REVERSING VALVE COMMON RELAY OUTPUT TERMINALS www aaon com WattMaster Overlay...

Page 7: ...Rev1D SW EXP VLV 4 BLACK BLACK WHITE WHITE RED RED GREEN GREEN EXP VLV 2 EXP VLV 1 EXP VLV 3 E BUS LEAVING WATER TEMP OPEN GND GND MODBUS Connect to VCC X or VCCX2 Controller Figure 3 RSMV HP Outputs Wiring 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 t...

Page 8: ...ne Temperature Sensor 3 TEMP3 6 Coil Suction Line Temperature Sensor 4 TEMP4 7 Leaving Water Temperature Sensor 1 TEMP5 Binary Inputs 1 Compressor Status 1 BIN1 2 Compressor Status 2 BIN2 3 Coil Temperature Switch Proof of Water Flow BIN3 4 Not Used BIN4 Analog Outputs 0 10 VDC 1 Modulating Compressor AOUT1 2 Condenser Valve Signal AOUT2 Stepper Motor Outputs 1 Expansion Valve 1 EXV 1 2 Expansion ...

Page 9: ...on the Reversing Valve RSMV HP Inputs Outputs RSMV HP Inputs Outputs 5V VDC Power This output is a 5 VDC output that supplies power to the Suction Pressure Transducer SP Suction Pressure Transducer The Suction Pressure Sensor is 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 This tempe...

Page 10: ...VFD compressor as required to maintain the Suction Saturated Temperature Setpoint At that point each RSMV will modulate its VFD compressor and enable the fixed compressor as necessary to maintain the Suction Saturated Temperature Setpoint for that circuit If the VFD compressor reaches 100 for the Stage Up Delay and the Suction Saturated Temperature is still above setpoint then the fixed compressor w...

Page 11: ...th an installed Coil Temperature Switch a Defrost Cycle is available If the compressor s are operating in the Heating Mode and the Defrost Coil Temperature Switch closes the unit will enter the Defrost Mode provided the user adjustable Defrost Interval Timer has elapsed since the last Defrost Cycle In the Defrost Cycle the reversing valve signal is switched to the opposite operation and the compre...

Page 12: ...s and change configurations ENTER Use the ENTER key to navigate through the Main Menu Screen categories RSMV HP Main Screens Map Refer to the following map when navigating through the LCD Main Screens To scroll through the screens press the MENU button RSMV HP 1072vXXX SYSTEM STATUS SENSOR STATUS ALARMS ALARM HISTORY SETPOINT STATUS Press to scroll through SYSTEM STATUS Screens Press to scroll thro...

Page 13: ...US SOFTWARE 1072vXXX ADDRESS XXX CURRENT SOFTWARE VERSION You can access the protected screens from this screen by holding the UP button for 5 seconds CURRENT BOARD ADDRESS E BUS COMMUNICATION DIAGNOSTICS Number of COMM packets received SYS TYPE WSHP HEATPUMP COOLONLY CURRENT SYSTEM TYPE OF COMP OF COMPRESSORS OF EXVs EV C OF EXPANSION VALVES EV Evaporator EXVs C Condenser EXVs COMP A1 MOD OR FIXE...

Page 14: ... board address OFF MODULATING POSITION 0 100 COMP A2 D2 ON OFF COMPRESSOR A2 B2 C2 D2 based on board address ON OFF FORCE EXV A1 D1 0 EXV A2 D2 0 CONDENSER FAN NOT USED OFF MODULATING POSITION 0 100 EXV A2 B2 C2 D2 based on board address EXV VALVE POSITION 0 to 100 percent H2O VALV NOT USED ON OFF FORCE WATER VALVE NOT USED ON OFF FORCE EXV A3 D3 0 EXV A3 B3 C3 D3 based on board address EXV VALVE ...

Page 15: ...s Screens From the SENSOR STATUS Screen press ENTER to scroll through the screens SENSOR STATUS HEAD XXX PSI HEAD PRESSURE READING FROM INPUT Setpoint Status Screens Refer to the following map when navigating through the Setpoint Status Screens From the SETPOINT STATUS Screen press ENTER to scroll through the screens SETPOINT STATUS HEADPRSP 340 PSI HEAD PRESSURE SETPOINT Valid range is 275 to 475...

Page 16: ...al is lost after activation This will cause an alarm and will shut down the compressor relay The system will retry after 5 minutes LOW SUPERHEAT 1 4 SH1 SH4 DETECTED This alarm will be activated when the Superheat is less than 4 degrees for 2 minutes during normal operation or for 4 minutes during the first 10 minutes The system will shut down and will retry after 5 minutes HIGH SUPERHEAT 1 4 SH1 S...

Page 17: ...e SP SENSE No Suction Pressure Sensor Detected HIGH HP High Head Pressure HP SENSE No Head Pressure Sensor Detected CL TMP 1 Coil Temp 1 Failure CL TMP 2 Coil Temp 2 Failure CL TMP 3 Coil Temp 3 Failure CL TMP 4 Coil Temp 4 Failure COMP 1 FL Compressor 1 Failure COMP 2 FL Compressor 2 Failure LOW SH1 Low Superheat 1 LOW SH2 Low Superheat 2 LOW SH3 Low Superheat 3 LOW SH4 Low Superheat 4 HI SH1 Hig...

Page 18: ... Head Pressure Sensor BIN 1 BIN 4 ON OFF BINARY INPUTS 1 4 Displays the current status of each Binary Input TMP1 TMP 4 VLT X XX COIL TEMPERATURE SENSORS 1 4 VOLTAGES Displays the current voltage of the Coil Temperature Sensor TMP5 VLT X XX LEAVING WATER TEMPERATURE SENSOR 5 VOLTAGE Displays the current voltage of the 2nd Coil Temperature Sensor FORCE MODE ON OFF FORCE MODE Displays the current sta...

Page 19: ...the name of the alarm and how many times the alarm has occurred since you last cleared the alarms The 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 Address Screen ADDRESS 1 152 CURRENT BOARD ADDRESS Configure the address according to which refrigerant cir...

Page 20: ...t up when Compressor Status 1 contact is closed BIN2 This green LED will light up when Compressor Status 2 switch is closed BIN3 This green LED will light up when the Outside Coil Temperature switch is closed Relay LEDs RLY1 RLY4 These green LEDs will light up when the relays are enabled and will stay lit as long as they are active RSMV HP Stepper Motor Valve LEDs EXV 1 This green LED will light u...

Page 21: ...als PR OUT and GND terminals and compare it to the appropriate 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 defective and will need to be replaced See the OE275 01 Suction Pressure Transducer Pressure Temperature and Voltage Chart for R410A Refrigerant testin...

Page 22: ...istance Voltage for Type III 10 K Ohm Thermistor Sensors Temp ºF Temp ºC Resistance Ohms Voltage Input VDC 10 23 33 93333 4 51 5 20 55 80531 4 45 0 17 77 69822 4 37 5 15 60552 4 29 10 12 22 52500 4 2 15 9 44 45902 4 1 20 6 66 40147 4 002 25 3 88 35165 3 891 30 1 11 30805 3 773 35 1 66 27140 3 651 40 4 44 23874 3 522 45 7 22 21094 3 39 50 10 18655 3 252 52 11 11 17799 3 199 54 12 22 16956 3 143 56 ...

Page 23: ...sducer measurements reference Table 5 below 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 1 2 117 3 3 467 1 3 133 3 4 484 1 4 150 3 5 500 1 5 167 3 6 517 1 6 183 3 7 534 1 7 200 3 8 550 1 8 217 3 9 567 1 9 233 4 0 584 2 0 250 4 1 600 2 1 267 4 2 617 2 2 283 4 3 634 2 3 300 4 ...

Page 24: ...TION Condenser Options 1 Cond per 1 RSMV USE or TO CHANGE Select the 1 Condenser per 1 RSMV option on the above Hand Held Service Tool Screen Single Condenser Per 1 Module In Single Condenser Per 1 Module wiring configuration the Condenser Signal is wired to AO2 and the Condenser Relay RLY3 is enabled Refer to the figures below for Prism 2 configuration and Modular Service Tool Screen selection ...

Page 25: ...V RSMV HP Condenser Options Configuration Screen RSM 1 4 CONFIGURATION Condenser Options 1 Cond per 2 RSMVs USE or TO CHANGE Select the 1 Condenser per 2 RSMVs option on the above Hand Held Service Tool Screen Figure 7 Prism 2 Condenser Configuration If using 4 modules the Condenser Signal is wired toAO2 on the 1st and 3rd modules but not the 2nd and 4th modules and the Condenser Relay RLY3 is enab...

Page 26: ...d 3rd modules and the Condenser Relay RLY3 is enabled on the 1st module but not the 2nd 3rd modules Refer to the figures below for Prism 2 configuration and Modular Service Tool Screen selection RSMV RSMV HP Condenser Options Configuration Screen RSM 1 4 CONFIGURATION Condenser Options 1 Cond for 3 RSMVs USE or TO CHANGE Select the 1 Condenser for 3 RSMVs option on the above Hand Held Service Tool S...

Page 27: ...r 4th modules and the Condenser Relay RLY3 is enabled on the 1st module but not the 2nd 3rd or 4th modules Refer to the figures below for Prism 2 configuration and Modular Service Tool Screen selection RSMV RSMV HP Condenser Options Configuration Screen RSM 1 4 CONFIGURATION Condenser Options 1 Cond for 4 RSMVs USE or TO CHANGE Select the 1 Condenser for 4 RSMVs option on the above Hand Held Service...

Page 28: ...s configuration only applies when using the RSMV HP Select this configuration when Expansion Valve 3 is wired and Expansion Valve 4 is not wired If both are connected leave this selection blank Copeland VFD Configuration Select this configuration if the RSMV is controlling a Copeland VFD through the MODBUS connection Single Compressor Startup Select this configuration if the desired startup routine e...

Page 29: ...RSMV HP Technical Guide NOTES 29 ...

Page 30: ...NOTES RSMV HP Technical Guide 30 ...

Page 31: ...RSMV HP Technical Guide NOTES 31 ...

Page 32: ...OK 74107 2728 Ph 918 583 2266 Fax 918 583 6094 AAON Part No V87400 WM Form AA RSMVHP TGD 01C Printed in the USA Copyright April 2018 All Rights Reserved AAON WattMaster Controls Inc 8500 NW River Park Drive Parkville MO 64152 ...

Reviews: