Retro Aire RQTH Installation Operation & Maintenance Download Page 15

Initial Power-Up Or Power Restoration

When power is applied, either for first time or after power 

failure, board will initialize.  

•  During initialization, LED1 will be lit continuously for 

approximately 5 seconds. 

•  Following initialization, random-start timer is initiated.  

This timer adds randomly selected 5-120 seconds to 

start-up sequence, reducing possibility of multiple units 

starting at same time.

•  Once random start timer has expired, 180 second anti-

short-cycle timer is initiated. LED1 blinks two-flash 

code.  (Anti-short-cycle timer prevents compressor 

from rapid cycling.)  

•  After the anti-short-cycle timer expires, LED1 blinks a 

one-blink code, indicating normal operation.

Figure 12 

Indicator LED1

LED1

SEQUENCE OF OPERATION

Fan Operation

Some thermostats are equipped with an auto/on fan 

switch.

• When this switch is placed in the on position the indoor 

fan will run continuous.

• When the switch is in the auto position the indoor fan 

will cycle with the call for heating or cooling.

Fan Purge

After the room thermostat has been satisfied, the purge 

feature allows the indoor fan to remain on for an additional 

60 seconds. This increases efficiency by pulling the 

remaining energy from the unit.

Anti-Short Cycle –Random Start Timer

The anti-short cycle timer feature will protect the compres-

sor from short cycling. Once the room temperature is sat-

isfied the ASCT will not allow a compressor restart until a 

three-minute time period has elapsed. If power is removed 

from the unit, an additional random time, between 5 and 

120 seconds will be added to the ASCT to prevent multiple 

units in the same building from re-starting simultaneously.

Cooling Operation

• Place system switch in 

cool

 mode and adjust the 

setpoint temperature below room temperature.

• The compressor and fan motors will start and cooling 

will begin. Cooling operation will continue until room 

temperature falls below the setpoint temperature.

• Place setpoint temperature above room temperature. 

The compressor will stop while the indoor fan remains 

on for an additional sixty seconds.

• After the compressor de-energizes the anti-short cycle 

timer will prevent a re-start until after the time period 

has expired. LED blink code of two-flashes indicates a 

call for compressor during the ASCT period.

• If the outdoor temperature falls below 25°F, the unit 

will not run cooling operation.

Heating Operation 

Single Stage Thermostat Heating Operation

• Place the system switch in 

heat 

mode and adjust the 

setpoint temperature above the room temperature.

• The compressor and fan motors will start and 

heating will begin. Heating operation will continue 

until the room temperature rises above the setpoint 

temperature.

• If the outdoor temperature is below approximately 

40°F during a call for heating the compressor and 

outdoor fan will de-energize and electric heat will 

energize. 

• Place the setpoint temperature below the room 

temperature. Heating will stop while the indoor fan 

remains on for an additional sixty seconds.

• An LED blink code of three flashes indicates a call for 

heat while compressor is locked out due to an outdoor 

coil freeze condition.

• After the compressor de-energizes the anti-short cycle 

timer will prevent a re-start until after the time period 

has expired. An LED blink code of two-flashes indicates 

a call for compressor during the ASCT period

Two Stage Thermostat Heating Operation

• For two stage thermostats only, place the setpoint high 

enough to energize second stage heating.

• The compressor will stop and the electric heat 

will energize. Heating operation will continue until 

the room temperature rises above the setpoint 

temperature.

• When the room temperature rises and satisfies the 

thermostat’s second stage heating demand, the electric 

heat will switch off and the compressor will start in 

heating mode.

• When the room temperature rises above the setpoint 

to satisfy the thermostat’s first stage heating demand 

the compressor will stop while the indoor fan remains 

on for an additional sixty seconds.

Made in USA                                                                               15 

PN 240010236 REV. D [12/15/2018]

Summary of Contents for RQTH

Page 1: ...p Installation Operation Maintenance Manual Direct Replacement for 1 5 2 Ton Carrier 50QT RQTH Manufactured by ECR International Inc 2201 Dwyer Avenue Utica NY 13501 Tel 800 253 7900 www ecrinternational com PN 240010236 REV D 12 15 2018 ...

Page 2: ... 4 Dimensional Physical Data 5 General Product Information 8 Enclosure Preparation 9 RQTH Installation 10 Electrical Connections 11 Final Inspection and Start up 12 Sequence of Operation 15 Maintenance 16 Troubleshooting 17 Electrical Specifications 19 Operational Performance Data 20 Condenser Louver Replacement 21 Warranty 22 AHRI Certified is a trademark of the Air Conditioning Heating and Refri...

Page 3: ...service department of all damage and is responsible for filing any necessary claims with carrier Customer Service 800 228 9364 Shipping damage MUST be reported to the carrier IMMEDIATELY Examine exterior Remove cover and examine compressor and piping for signs of damage RECEIVING INFORMATION General Information Installation shall be completed by qualified agency Retain this manual for future refer...

Page 4: ...e of such requirements United States National Electrical Code ANSI NFPA 70 Canada CSA C22 1 Canadian Electrical Code Part 1 IMPORTANT SAFETY INFORMATION DANGER Indicates a hazardous situation which if not avoided WILL result in death or serious injury WARNING Indicates a hazardous situation which if not avoided could result in death or serious injury CAUTION Indicates a hazardous situation which i...

Page 5: ...Figure 1 RQTH Installation Dimensions Inches mm Models 18 24 DIMENSIONAL PHYSICAL DATA Made in USA 5 PN 240010236 REV D 12 15 2018 ...

Page 6: ...ration Chassis Mounted 18 305 138 16 x 24 x 1 24 305 138 16 x 24 x 1 DIMENSIONAL PHYSICAL DATA Table 1 Dimensions Shipping Weights and Return Air Filter Sizes Figure 2 RQTHC RQTH Overall Dimensions Inches mm Models 18 24 27 44 696 9mm 13 21 335 4mm 18 39 467 2mm 28 19 716mm 26 21 665 7mm 2 50 63 5mm 33 94 862mm 43 87 1114 4mm 6 Made in USA PN 240010236 REV D 12 15 2018 ...

Page 7: ...age Knockouts Line Voltage Route See Unit Wiring Diagram For Connections Figure 3 Line Voltage Routing Knock outs Location DIMENSIONAL PHYSICAL DATA Removable Evaporator Extension Made in USA 7 PN 240010236 REV D 12 15 2018 ...

Page 8: ...tical heat pump SPVHP R 410A refrigerant Custom outdoor louver required for performance Insulated top discharge indoor compartment Vertical discharge allows ducting to top of room s Models can be applied in non ducted return air applications RQTH models are limited range heat pumps Heat pump operation will cease at approximately 40 F 4 4 C outdoor temperature Cooling opertion will cease at approxi...

Page 9: ...e bottom of RQTH chassis flush with bottom inside edge of wall sleeve Air filter All models must have air filter installed prior to operation Use chassis mounted air filter provided For optional return air access panel remove and discard filter from unit and install access panel with supplied filter in place 12 00 Height Off The Floor 291 8 455 8 12 00 Min Distance to interior Walls A A 43 16 12 1...

Page 10: ...ls freezing short cycling and constant operation See Figure 8 NOTICE Carrier series use internal drain system Verify existing drain system is in working condition and able to move condensate freely 5 Verify internal condensate drain on replacement unit is free of any obstructions and free flowing Pour at least 16 oz clear water through base pan and evaporator drain pan 6 Slide chassis into wall sl...

Page 11: ...d wiring diagram for further instructions and wire connections F Each unit is equipped for 24v wall thermostat connection NOTICE RQTH units are wired for 230v primary voltage from manufacturer Transformer must be rewired by installer if job site voltage is 208v ELECTRICAL CONNECTIONS Choosing Thermostat ECR offers a remote thermostat that is compatible with Model RQTH 18 24 See the latest price li...

Page 12: ...ge 5 and Figures 9 and 10 page 13 Verify indoor blower wheels and outdoor fan blades are secured to their motor shafts Ensure all sheet metal panels are in place and secure Verify drain stub if used is secure to base pan and condensate drain is functioning properly Verify chassis is properly fit to wall sleeve and securely mounted to surrounding framing FINAL INSPECTION AND START UP Heating 1 Set ...

Page 13: ...termine whether unit operates as straight cooling or as heat pump See Figures 9 and 10 Jumper right pin to center pin for heat pump operation Heat pump jumper is factory set and does not require filed adjustment Jumper left pin to center pin for straight cooling operation TEST Jumper selects normal or test mode NOTICE Do not leave unit operating with TEST jumper in TEST position Jumper is for test...

Page 14: ...TEST JUMPER HEAT PUMP JUMPER Figure 11 Circuit Board FINAL INSPECTION START UP 14 Made in USA PN 240010236 REV D 12 15 2018 ...

Page 15: ...setpoint temperature above room temperature The compressor will stop while the indoor fan remains on for an additional sixty seconds After the compressor de energizes the anti short cycle timer will prevent a re start until after the time period has expired LED blink code of two flashes indicates a call for compressor during the ASCT period If the outdoor temperature falls below 25 F the unit will...

Page 16: ...ee flashes indicates a call for heat while compressor is locked out due to an outdoor coil freeze condition LED blink code of five flashes indicates auxiliary heat operation during a call for second stage heating After the compressor de energizes the anti short cycle timer will prevent a re start until after the time period has expired An LED blink code of two flashes indicates a call for compress...

Page 17: ...it and remove necessary access panels 1 Remove access panel Visually inspect equipment Look for obvious changes in unit such as damaged coils or evidence of extended wear on any moving parts 2 Check for unusual odors or leaks examples burnt motor windings water or refrigerant Verify base pan is clean 3 Clean or replace return air filter as needed Check filter at least once month Some environments ...

Page 18: ...tat is set to auto mode once thermostat is satisfied fan will stay energized for extra 60 seconds to purge unit of excess cool or warm air in plenum If thermostat fan switch is set to ON fan will stay energized regardless of whether thermostat is satisfied or not Only way to turn fan off is to turn unit off or turn thermostat fan switch to AUTO Thermostat calls for heat but no heat comes out of un...

Page 19: ...eed tap changes as required by job site voltage and or external static pressure ESP Speed tap changes may need to be changed from manufacturer settings Manufacturer will not be liable for any system problems that could arise if motor speed is not changed to match application Table 3 Indoor motor speed tap selection chart Model ESP In w c mm w c 230V 208V 197V 18 24 0 1 3 Blk Blk Blk 0 2 5 0 3 8 Ta...

Page 20: ...ndoor Fan Motor Outdoor Fan Motor Electric Heat Unit Electrical Ratings Volt Min RLA LRA FLA Hp FLA Hp Htr Volt W HA TCA THA MCA MOCP H Wire 208 230V 197 7 3 48 1 3 0 25 0 5 0 5 0 125 0 125 5 208 4089 19 7 9 6 21 0 26 2 30 H Wire 230 5000 21 7 23 0 28 8 7 280 5725 27 5 28 8 36 0 40 H Wire 230 7000 30 4 31 7 39 7 Table 6 RQTH 24 Electrical Specifications Power Supply Volt 1 60 Compressor Indoor Fan...

Page 21: ...335 650 307 600 283 60 71 OPERATIONAL PERFORMANCE DATA Table 7 Performance Data CONDENSER LOUVER REPLACEMENT Condenser Louver Replacement NOTICE Use of louver other than supplied with the unit will effect efficiency and service life Use only Louver supplied by unit manufacture for the RQTH Existing Carrier wall sleeve shall be retained in all applications provided RQTH unit is installed as requrie...

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