Bard QH302 Solid State Heat Pump Control Troubleshooting Procedure, Checking Temperature Sensor

Page 29

SOLID STATE HEAT PUMP CONTROL TROUBLESHOOTING PROCEDURE

1.NOTE: A thorough understanding of the defrost cycle sequence is essential. Review that section earlier in this manual prior to troubleshooting the control. Turn on AC power supply to unit.

2.Turn thermostat blower switch to “fan on” – the indoor blower should start. (If it doesn’t, troubleshoot indoor unit and correct problem.)

3.Turn thermostat blower to “auto” position. Indoor blower should stop. NOTE: Many models have a 1-minute blower time delay on “off” command; wait for this to time-out.

4.Set system switch to “heat” or “cool”. Adjust thermostat to call for heat or cool. The indoor blower, compressor and outdoor fan should start.

NOTE: If there was no power to 24 volt transformer, the compressor and outdoor fan motor will not start for 5 minutes. This is because of the compressor short cycle protection.

CHECKING TEMPERATURE SENSOR

1.Disconnect temperature sensor from board and from outdoor coil.

2.Use an ohmmeter and measure the resistance of the sensor. Also use ohmmeter to check for short or open.

3.Check resistance reading to chart of resistance use sensor ambient temperature. (Tolerance of part is ± 10%.)

4.If sensor resistance reads very low, then sensor is shorted and will not allow proper operation of the heat pump control.

5.If sensor is out of tolerance, shorted, open, or reads very low ohms then it should be replaced.

TABLE 6

TEMPERATURE (F) VS RESISTANCE (R) OF TEMPERATURE SENSOR

 

F

R

F

R

F

R

F

R

 

 

 

 

 

 

 

 

 

 

 

 

-25.0

196871

13.0

56985

53.0

19374

89.0

7507

 

 

-24.0

190099

14.0

55284

52.0

18867

90.0

7334

 

 

-23.0

183585

15.0

53640

53.0

18375

91.0

7165

 

 

-22.0

177318

16.0

52051

54.0

17989

92.0

7000

 

 

-21.0

171289

17.0

50514

55.0

17434

93.0

6840

 

 

-20.0

165487

18.0

49028

56.0

16984

94.0

6683

 

 

-19.0

159904

19.0

47590

57.0

16547

95.0

6531

 

 

-18.0

154529

20.0

46200

58.0

16122

96.0

6383

 

 

-17.0

149355

21.0

44855

59.0

15710

97.0

6239

 

 

-16.0

144374

22.0

43554

60.0

15310

98.0

6098

 

 

-15.0

139576

23.0

42295

61.0

14921

99.0

5961

 

 

-14.0

134956

24.0

41077

62.0

14544

100.0

5827

 

 

-13.0

130506

25.0

39898

63.0

14177

101.0

5697

 

 

-12.0

126219

26.0

38757

64.0

13820

102.0

5570

 

 

-11.0

122089

27.0

37652

65.0

13474

103.0

5446

 

 

-10.0

118108

28.0

36583

66.0

13137

104.0

5326

 

 

-9.0

114272

29.0

35548

67.0

12810

105.0

5208

 

 

-8.0

110575

30.0

34545

68.0

12492

106.0

5094

 

 

-7.0

107010

31.0

33574

69.0

12183

107.0

4982

 

 

-6.0

103574

32.0

32634

70.0

11883

108.0

4873

 

 

-5.0

100260

33.0

31723

71.0

11591

109.0

4767

 

 

-4.0

97064

34.0

30840

72.0

11307

110.0

4663

 

 

-3.0

93981

35.0

29986

73.0

11031

111.0

4562

 

 

-2.0

91008

36.0

29157

74.0

10762

112.0

4464

 

 

-1.0

88139

37.0

28355

75.0

10501

113.0

4367

 

 

0.0

85371

38.0

27577

76.0

10247

114.0

4274

 

 

1.0

82699

39.0

26823

77.0

10000

115.0

4182

 

 

2.0

80121

40.0

26092

78.0

9760

116.0

4093

 

 

3.0

77632

41.0

25383

79.0

9526

117.0

4006

 

 

4.0

75230

42.0

24696

80.0

9299

118.0

3921

 

 

5.0

72910

43.0

24030

81.0

9077

119.0

3838

 

 

6.0

70670

44.0

23384

82.0

8862

120.0

3757

 

 

7.0

68507

45.0

22758

83.0

8653

121.0

3678

 

 

8.0

66418

46.0

22150

84.0

8449

122.0

3601

 

 

9.0

64399

47.0

21561

85.0

8250

123.0

3526

 

 

10.0

62449

48.0

20989

86.0

8057

124.0

3452

 

 

11.0

60565

49.0

20435

87.0

7869

 

 

 

 

12.0

58745

50.0

19896

88.0

7686

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Manual

2100-420H

 

 

 

 

 

 

 

Page

29 of 34

Image 29
Contents Instructions Models QH243 QH302 QH362 QH422 QH482 QH602 Qtec Series Packaged Heat Pump InstallationContents For More INFORMATION, Contact These Publishers Getting Other Information and PublicationsFactory BUILT-IN Electric Heat Table Qtec Model NomenclatureElectrical Specifications on page 6 a Electrical SpecificationsModel Unit Dimensions Unit Removal from Skid Shipping DamageAIR Seal Under Qtec Unit Removal of Unit from SkidHandling Unit After Removal from Skid Minimum Installation HeightGeneral Unit on Appliance CartInstallation with Free Blow Plenum Ducted Application Filters Duct WorkSupply Duct Connections Filter LocationFresh AIR Intake Optional Side Drain Side View InstallationCondensate Drain Standard Rear DrainUnit Mounting Service LightRear Drain TOP View Removing Locking Screws from Wheels Installation InstructionsMounting the Unit Wiring LOW Voltage Wiring Wiring Main PowerComponent Location Operating Voltage RangeLOW Voltage Connections for DDC Control LOW Voltage ConnectionsWall Thermostats Thermostat Predominant FeaturesRemote Thermostat Wiring Diagram Thermostat Option Unit Mounted Thermostat Wiring Diagram Thermostat Option Unit Mounted Thermostat Wiring Diagram Thermostat Option Start UP Mist Eliminator Service Service HintsBarometric Fresh AIR Damper Standard Vent OptionsFresh AIR Damper Removal Qerv Removal Sequence of Operation Pressure Service PortsOptional Climate Controls Sequence of Operation Heat Pump Control Board HPCDefrost Cycle LOW Pressure Control Bypass TimerTroubleshooting TroubleshootingTemperature F VS Resistance R of Temperature Sensor Solid State Heat Pump Control Troubleshooting ProcedureChecking Temperature Sensor Don’t Troubleshooting GE ECM MotorsReplacing ECM Control Module Troubleshooting GE ECM Motors CONT’DFAN Blade Setting FAN Blade Dimensions FAN Blade Setting Dimensions Refrigerant ChargeSuper Heat AT Compressor Indoor Blower PerformanceModel Temp Pressure Cooling Pressure ALL Temperatures in Degrees FReturn AIR Temperature Entering Outdoor Coil Model Pressure Heating Pressure ALL Temperatures in Degrees F

QH482, QH243, QH302, QH422, QH602 specifications

Bard has established itself as a leader in the heating, ventilation, and air conditioning (HVAC) industry with its innovative line of products, including the Bard QH series. Models such as QH362, QH602, QH422, QH302, and QH243 showcase the perfect blend of performance, efficiency, and advanced technology.

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