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CXM Electronic Heat Pump Control

Application, Operation and Maintenance Guide

TABLE OF CONTENTS

General Operating Parameters Physical Dimensions and Layout Product Specification Catalog Information Control Features Field Selectable Inputs Safety Features Diagnostic Features Unit Operation Description Engineering Guide Specifications Typical Schematic Sensors / Thermistors Thermostat Details Troubleshooting 3 3 4 4 4 6 6 6 6 7 8 9 11-13

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DXM / CXM Electronic Control Features Comparison

Basic Features

High and Low Refrigerant Pressure Protection Low Water Flow Protection Anti-Short-Cycle Time-Delay Emergency Shutdown Random Start Night Setback with Override Condensate Overflow Sensor Pump Restart Alarm (dry contact output) Outdoor Air Damper Control Motorized Water Valve Control T-Stat Inputs Compatible with Triacs True 24 VAC Thermostat Signals S S S S S S S S S S O S S S S S S O E/Mech CMC-2001 CMC-2005 CMC-2010 S Klixon O O O O O S Klixon S S S S S S O E E S Klixon S S S S S S O E E S Klixon S S S S S S O E E S S S S S S CXM S S DXM S S S S S S S S S S S S S S S S S S S S S S S S S S 3 3 3 S S S S S S S S S S S 3 S S S S S S S S O S S S S O = Optional E = Either WV or OAD S S S S S O DXM-Lon S Thermistor S S S S S S S S S S S S S S S S S S S S S S S S S 3 S S S S S S S S S S S S S S Thermistor Thermistor

Advanced Features

Reduced Reversing Valve Operation High/Low Fan Speed Intelligent Reset High and Low Voltage Protection Air Coil Freeze Protection Thermostat Type Select (Y,O or Y,W) Electric Heat Control Outputs Hot Gas Reheat Control Boilerless Electric Heat Control 2 Stage Compressor Capacity Control Dehumidistat Input Reversing Valve Mode Select (O or B) Hydronic Economizer Control Freeze Setpoint Select (water,antifreeze) Multiple Units on One Thermostat

Service and Reliability Features

CE Approval Unit Performance Sentinel (UPS) Service Test Mode LED Fault and Status Lights Removable Low Voltage Connector Noise Immune Communication Protocol Harness-Type Factory Wiring Connectors Fully Noise-Tested Design

DDC / Energy Management Features

Echelon / LonMark compatible Johnson Controls Metasys compatible Leaving Water Temperature Display Leaving Air Temperature Display Demand Load Shed Room Air Temperature and Setpoint Display S = Standard DXM-Lon: With LonMark Module E/Mech = ElectroMechanical Controls

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CXM Overview

The CXM control is a robust, microprocessor based heat pump controller which is low cost and simple to use, yet provides all the necessary features to improve the operation and safety of water source heat pumps. CM Part Number: 17B0001N01 CXM Control Board Power Requirements: CXM only power draw Normally 5 VA draw at 24VAC Maximum 9 VA draw at 24VAC A dedicated 24VAC, 50-60Hz, 1Ph, 40VA transformer minimum is required for typical wshp application. Relay Contact Ratings: The following relays are mounted on the CXM control. Compressor Relay: 40VA at 24Vac Alarm Relay: 28VA at 24Vac Grounding: The control board is grounded through two of the metal standoffs. Field connection ratings for the CXM Control: "A" terminal: 20VA at 24VAC

General Operating Parameters

The following are general operating parameters for the CXM control: Operating Environment: -40°F to 176°F and up to 95% relative humidity, non-condensing. Storage Environment: -40°F to 185°F and up to 95% relative humidity, non-condensing.

Physical Dimensions and Layout

Factory 0.250" Quick Connects 4.00"

BR C

BRG

CCG

CC

Comp Relay

Test

Off On

P2

R

JW3 JW2 FP1 Low Temp FP2 Low Temp

Y

6.00"

Field Thermostat Connections

Y W O G R C AL1 AL2 A P1

Micro

HP HP LP LP FP1 FP1 FP2 FP2 RV RV CO 12 CO

1

Factory Low Voltage Molex connector for unit harness

5.50"

JW1- AL2 Dry

Status LED

P3

1 24Vdc

EH1

Factory Low Voltage Molex connector for electric heat harness

4 EH2

3/8" standoff

Alarm Relay CO

17B0001N01 Rev A 9/22/98 1.50" 4 Mounting Screws: #6 sheet metal screw 1" long

3.50"

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Product Specification

Features

· Anti-short cycle protection · High and Low pressure cutouts · Water Coil freeze protection · Air Coil freeze protection · Random Start · Unit Performance Sentinel · Over/Under Voltage protection · Diagnostic LED · Reset Lockout at unit or disconnect · Intelligent Reset · Condensate Overflow sensor · Test Mode · Electric Heat Outputs · Accessory Water Valve Connection · Optional LonWorks Control Retry Mode - If the control is attempting a retry of a fault, the status LED will slow flash (slow flash=one flash every 2 seconds) to indicate the control is in process of retrying. NOTE: In the following field configuration options, jumper wires should be clipped ONLY when power is removed from the CXM control. Water Coil Freeze Protection Limit Setting - Jumper 3 (JW3-FP1 Low Temp) provides field selection of temperature limit setting for FP1 to be 30°F or 10°F. Not Clipped=30°F. Clipped=10°F. Air Coil Freeze Protection Limit Setting - Jumper 2 (JW2-FP2 Low Temp) provides field selection of temperature limit setting for FP2 to be 30°F or 10°F. Not Clipped=30°F. Clipped=10°F. Alarm Relay Setting - Jumper 1 (JW1-AL2 Dry) provides field selection of Alarm Relay terminal AL2 to be jumpered to 24Vac or to be dry (no connection). Not Clipped=AL2 connected to R. Clipped=AL2 dry contacts (no connection). DIP Switches Note: In the following field configuration options, dip switches should only be moved when power is removed from the CXM control, to insure proper operation. Unit Performance Sentinel Disable - Dip Switch 1 provides field selection to disable the UPS feature. Table 1. LED & Alarm Relay Operations

Description of Operation Normal Mode Normal Mode with UPS Warning CXM is non-functional Fault Retry Lockout Over/Under Voltage Shutdown Test Mode - No fault in memory Test Mode - HP Fault in memory Test Mode - LP Fault in memory LED On On Off Slow Flash Fast Flash Slow Flash Flashing Code 1 Flashing Code 2 Flashing Code 3 Alarm Relay Open Cycle (closed 5 sec., Open 25 sec.) Open Open Closed Open (Closed after 15 minutes) Cycling Code 1 Cycling Code 2 Cycling Code 3 Cycling Code 4 Cycling Code 5 Cycling Code 6 Cycling Code 7 Cycling Code 8

Test mode can be exited by shorting the test terminals for 3 seconds. Test mode can also be entered and exited by cycling the G input, 3 times within a 60 second time period.

Field Selectable Inputs

Test Mode - Test Mode allows the service personnel to check the operation of the control in a timely manner. By momentarily shorting the test terminals, the CXM control enters a 20 minute Test Mode period in which all time delays are sped up 15 times. Upon entering Test Mode, the Status LED will flash a code representing the last fault. For Diagnostic ease at the thermostat, the alarm relay will also cycle during test mode. The Alarm relay will cycle on and off similar to the status LED to indicate a code representing the last fault, at the thermostat. Note: Code 1 indicates there is no fault in memory; stated differently, the control has not faulted since the last power-down to power-up sequence.

On = Enabled. Off = Disabled. Stage 2 - Dip Switch 2 provides selection of whether compressor has an on delay. If set to stage 2, the compressor will have a 3 second delay before energizing. Also, if set for stage 2, the alarm relay will NOT cycle during test mode. On = Stage 1 . Off = Stage 2

Test Mode - FP1 Fault in memory Flashing Code 4 Test Mode - FP2 Fault in memory Flashing Code 5 Test Mode - CO Fault in memory Test Mode - Over/Under shutdown in memory Test Mode - UPS in memory Flashing Code 6 Flashing Code 7 Flashing Code 8

Special Notes and Examples: -Slow Flash = 1 flash every 2 seconds -Fast Flash = 2 flashes every 1 second -Flash code 2 = 2 quick flashes, 10 sec. pause, 2 quick flashes, 10 sec. pause, etc.

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Safety Features

The following safety features are provided to protect the compressor, heat exchangers, wiring and other components from damage caused by operation outside of design conditions. Anti-Short Cycle Protection- The control features a 5 minute anti-short cycle protection for the compressor. NOTE: The 5 minute anti-short cycle also occurs at power up. Random Start - The control features a 5-80 second random start upon power up. Fault Retry - In Fault Retry mode, the Status LED begins slow flashing to signal that the control is trying to recover from a fault input. The CXM control will stage off the outputs and then "try again" to satisfy the thermostat "Y" input call. Once the thermostat input calls are satisfied, the control will continue on as if no fault occured. If 3 consecutive faults occur without satisfying the thermostat "Y" input call, then the control will go to Lockout mode. The last fault causing the lockout will be stored in memory and can be viewed by going into test mode. Lockout - In Lockout mode, the Status LED will begin fast flashing. The compressor relay is turned off immediately. Lockout mode can be soft reset via the thermostat "Y" input or can be hard reset via the disconnect. The last fault causing the lockout will be stored in memory and can be viewed by going into test mode. Lockout with Emergency Heat - While in Lockout mode, if W becomes active, then Emergency Heat mode will occur. High Pressure Switch - When the High Pressure Switch opens due to high refrigerant pressures, the Compressor relay is de-energized immediately since the High Pressure Switch is in series with the compressor contactor coil. The High Pressure Fault recognition is immediate as well. High Pressure Lockout Code = 2 Example: 2 quick flashes, 10 sec pause, 2 quick flashes, 10 sec. pause, etc. Low Pressure Switch - The Low Pressure Switch must be open and remain open for 30 continuous seconds during "on" cycle to be recognized as a Low Pressure fault. If the low pressure switch is open for 30 seconds Page 6

prior to compressor power up it will be considered a low pressure (loss of charge) fault. The Low Pressure Switch input is bypassed for the initial 60 seconds of a compressor run cycle. Low Pressure Lockout Code = 3 Water Coil Freeze Protection (FP1) - The FP1 thermistor temperature must be below the selected freeze protection limit setting for 30 continuous seconds during a compressor run cycle to be recognized as a FP1 fault. The FP1 input is bypassed for the initial 60 seconds of a compressor run cycle. FP1 Lockout Code = 4 Air Coil Freeze Protection (FP2) - The FP2 thermistor temperature must be below the selected freeze protection limit setting for 30 continuous seconds during a compressor run cycle to be recognized as a FP2 fault. The FP2 input is bypassed for the initial 60 seconds of a compressor run cycle. FP2 Lockout Code = 5 Condensate Overflow - The Condensate Overflow sensor must sense overflow levels for 30 continuous seconds to be recognized as a CO fault. Condensate Overflow will be monitored at all times. CO Lockout Code = 6 Over/Under Voltage Shutdown - An Over/Under Voltage condition exists when the control voltage is outside the range of 19Vac to 30Vac. Over/Under Voltage Shutdown is self resetting in that if the voltage comes back within range of 19Vac to 30Vac for at least 0.5 seconds, then normal operation is restored. This is not considered a fault or lockout. If the CXM is in over/ under voltage shutdown for 15 minutes, the alarm relay will close. Over/Under Voltage Shutdown Code = 7 Unit Performance Sentinel-UPS (patent pending) - The UPS feature warns when the heat pump is operating inefficiently. A UPS condition exists when: a) in heating mode with compressor energized, if FP2 is greater than 125°F for 30 continuous seconds, or b) in cooling mode with compressor energized, if FP1 is greater than 125°F for 30 continuous seconds, OR FP2 is less than 40°F for 30 continuous seconds. If a UPS condition occurs, the control will immediately go to UPS warning. The status LED will remain on as if the control is in Normal mode. (see"LED and Alarm Relay Operation Table" ). Outputs of the control,

excluding LED and Alarm Relay, will NOT be affected by UPS. The UPS condition cannot occur during a compressor off cycle. During UPS warning, the alarm relay will cycle on and off. The cycle rate will be On for 5 seconds, Off for 25 seconds, On for 5 seconds, Off for 25 seconds, etc. Unit Performance Sentinel Warning Code = 8

Heating Stage 1 - To enter Heating Stage 1 mode, Y becomes active. The first time after power-up that there is a call for compressor, the compressor will follow a 5 to 80 second random start delay. There will also be a 5 min compressor anti-short cycle protection time as well. After the random start delay and the anti-short cycle delay, the compressor relay is energized. On all subsequent compressor calls, the random start delay is omitted. Heating Stage 2 - To enter Heating Stage 2 mode, W becomes active (Y already active). The G input must be active or the W input is ignored. The Compressor relay remains on. EH1 is turned on immediately. With continuing Heating Stage 2 demand, EH2 will turn on after 10 minutes. The EH2 will not turn on (or will turn off if already on) if FP1 temperature is greater than 45°F and FP2 is greater than 110°F. Emergency Heat - In Emergency Heat mode, W becomes active while Y is not active. The G input must be active or the W input is ignored. EH1 is turned on immediately. With continuing Emergency Heat demand, EH2 will turn on after 5 minutes. The FP1 and FP2 temperatures do not effect emergency heat operation.

Diagnostic Features

The Status LED on the CXM control advises the serviceman of the current status of the CXM control. The status LED can display either the current CXM mode or the last fault memory if in test mode. See Table 1 for a complete listing of codes. If the Fault type is "Primary" (HP, LP, FP1, FP2, or CO) then the Fault type will always be retained in memory (Primary faults will over write Secondary faults). If the Fault type is "Secondary" (Over/ Under Voltage or UPS) then the Fault type will only be retained if there are no "Primary" faults in memory. The Secondary Fault types will not "overwrite" the Primary fault memory.

Unit Operation Description

PowerUp - The unit will not operate until all the inputs and safety controls are checked for normal conditions. NOTE: The compressor will have a 5 minute anti-short cycle delay at power-up. Standby - In Standby mode, Y and W inputs are not active. Inputs O and G may be active. Compressor will be off. Cooling - To enter Cooling mode, Y and O become active. The first time after power-up that there is a call for compressor, the compressor will follow a 5 to 80 second random start delay. There will also be a 5 min compressor anti-short cycle protection time as well. After the random start delay and the anti-short cycle delay, the compressor relay is energized. On all subsequent compressor calls, the random start delay is omitted. Table 1a. Fault Description Table

Fault No fault in memory High Pressure Switch Low Pressure Switch or LOC Freeze Protection Coax - FP1 Freeze Protection Air Coil - FP2 Condensate overflow Over/Under Voltage Shutdown UPS Warning Fault LED Code 1 2 3 4 5 6 7 (Autoreset) 8

Engineering Guide Specifications

The following engineering guide specifications for the CXM control should be a part of all product submittals. CXM Control A microprocessor-based compressor controller (CXM) shall be provided to monitor and control unit operation. The control shall provide compressor and electric heater sequencing, high and low pressure monitoring, field selectable water and air coil freeze protection sensing, condensate overflow sensing, over/under voltage monitoring,and unit performance sentinel The control shall also provide for water valve connection, a test mode, short cycle protection, random start-up, as well as fault LED, fault memory, and intelligent fault retry.

The control shall employ a quick attach harness assemblies for low voltage connections to the CXM control board to aid in troubleshooting or Fault Condition replacement. An integral terminal There has been no fault since the last power-down block with screw terminals shall be to power-up sequence provided on the CXM control for all HP Open Instantly field low voltage connections. LP open for 30 continuous seconds before or

during a call (bypassed for first 60 seconds) FP1 below Temp limit for 30 continous seconds (bypassed for first 60 seconds of operation) FP2 below Temp limit for 30 continous seconds (bypassed for first 60 seconds of operation) Sense overflow (grounded) for 30 continous seconds "R" power supply is <19VAC or >30VAC

Unit Performance Sentinel Warning has occurred.

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Page 8

Product Design and Application Notes

Sensors

Pressure SwitchesAll pressure switches are designed to be normally closed during normal operating conditions, and to open upon fault. Condensate SensorThe condensate sensor input will fault upon sensing impedance less than 100,000 ohms for 30 continuous seconds. The recommended design uses a single wire terminated with a male 1/4" quick connect located in the drain pan at desired trip level. Upon a high condensate level the water will short between the air coil and the quick connect producing a resistance less than 100,000 Ohms. Since condensate is free of impuritites, it has no conductivity. Only the impurities from the drain pan and coil dust or dirt create the conductance. A second ground wire with appropriate terminal to the drain pan can be used with the control to replace the air coil ground path. The condensate sensor can also essentially be any open contact that closes upon a fault condition. Common Condensate Signals There is also a 1/4" quick connect terminal which can be connected to the CO terminal on an additional CXM controls to allow 2 CXM controls to share one condensate signal or sensor as found in larger two circuit equipment. Thermistor Temperature SensorsThe thermistor is available in the following configurations shown in Table 2. The thermistor is an NTC (negative temperature coefficient) type. The sensor has a 1% tolerance and follows the Table 3 and Chart 1 shown. Table 4 shows the nominal resistance at any given temperature and can be used for field service reference. The sensor will use a minimum of 24 awg wire and be epoxy embedded in the beryllium copper clip.

Resistance (kOhm)

Table 3. 1% Sensor Calibration Points

Minimum Temp (°F) Resistance (ohm) 78.5 77.5 76.5 75.5 33.5 32.5 31.5 30.5 1.5 0.5 0.0 9523 9650 10035 10282 30975 31871 32653 33728 80624 83327 84564 Maximum Resistanc e (ohm) 9715 9843 10236 10489 31598 32512 33310 34406 82244 85002 86264 Nominal Resistance (ohm) 9619 9746 10135 10385 31285 32190 32980 34065 81430 84160 85410

Chart 1. Thermistor Nominal Resistance

90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 Temperature (degF)

Table 2. Replacement Thermistor FP1, FP2 Part No.

Thermistor Type FP1 (Gray) FP2 (Violet) Tube OD 3/8, 1/2 5/8, 7/8 3/8, 1/2 5/8, 7/8 36 17B0005N06 N/A N/A N/A 48 N/A N/A 17B0005N02 N/A Lead Length In. 96 17B0005N04 17B0004N01 N/A N/A 192 N/A N/A 17B0005N05 17B0004N02

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Table 4. Nominal resistance at various temperatures

Thermostat Details

Thermostat Compatibility - Most all heat pump thermostats can be used with the CXM control. However Heat/ Cool stats are NOT compatible with the CXM. Anticipation Leakage Current - Maximum leakage current for "Y" is 50 mA and for "W" is 20mA. Triacs can be used if leakage current is less than above. Thermostats with anticipators can be used if anticipation current is less than that specified above. Thermostat Signals · "Y" and "W" have a 1 second recognition time when being activated or being removed. · "O" and "G" are direct pass through signals but are monitored by the micro processor. · "R" and "C" are from the transformer. · "AL1" and "AL2" originate from the alarm relay. · "A" is paralleled with the compressor output for use with well water solenoid valves. · The "Y" 1/4" quick connect is a connection point to the "Y" input terminal P1 for factory use. This "Y" terminal can be used to drive panel mounted relays such as the loop pump relay.

Temp (°C) Temp(°F) -17.8 -17.5 -16.9 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 0.0 0.5 1.5 10.4 12.2 14.0 15.8 17.6 19.4 21.2 23.0 24.8 26.6 28.4 30.2 32.0 33.8 35.6 37.4 39.2 41.0 42.8 44.6 46.4 48.2 50.0 51.8 53.6 55.4 57.2 59.0 60.8 62.6 64.4 66.2 68.0 69.8 71.6 73.4 75.2 77.0 78.8 80.6 82.4 84.2 86.0 87.8 89.6 91.4 93.2 95.0 96.8 98.6 100.4 102.2 104.0 105.8 107.6 109.4 111.2 113.0 114.8 116.6 118.4 120.2 122.0 123.8 125.6 127.4 129.2

Resistance (kOhm) 85.41 84.16 81.43 61.70 58.40 55.30 52.40 49.60 47.00 44.60 42.30 40.10 38.10 36.10 34.30 32.60 31.00 29.40 28.00 26.60 25.30 24.10 23.00 21.90 20.80 19.90 18.97 18.09 17.25 16.46 15.71 15.00 14.32 13.68 13.07 12.49 11.94 11.42 10.92 10.45 10.00 9.57 9.17 8.78 8.41 8.06 7.72 7.40 7.10 6.81 6.53 6.27 6.02 5.78 5.55 5.33 5.12 4.92 4.73 4.54 4.37 4.20 4.04 3.89 3.74 3.60 3.47 3.34 3.22 3.10

Temp (°C) Temp(°F) 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 131.0 132.8 134.6 136.4 138.2 140.0 141.8 143.6 145.4 147.2 149.0 150.8 152.6 154.4 156.2 158.0 159.8 161.6 163.4 165.2 167.0 168.8 170.6 172.4 174.2 176.0 177.8 179.6 181.4 183.2 185.0 186.8 188.6 190.4 192.2 194.0 195.8 197.6 199.4 201.2 203.0 204.8 206.6 208.4 210.2 212.0 213.8 215.6 217.4 219.2 221.0 222.8 224.6 226.4 228.2 230.0 231.8 233.6 235.4 237.2 239.0 240.8 242.6 244.4 246.2 248.0 249.8 251.6 253.4

Resistance (kOhm) 2.99 2.88 2.77 2.67 2.58 2.49 2.40 2.32 2.23 2.16 2.08 2.01 1.94 1.88 1.81 1.75 1.69 1.64 1.58 1.53 1.48 1.43 1.38 1.34 1.30 1.26 1.22 1.18 1.14 1.10 1.07 1.04 1.00 0.97 0.94 0.92 0.89 0.86 0.84 0.81 0.79 0.76 0.74 0.72 0.70 0.68 0.66 0.64 0.62 0.60 0.59 0.57 0.56 0.54 0.53 0.51 0.50 0.48 0.47 0.46 0.45 0.43 0.42 0.41 0.40 0.39 0.38 0.37 0.36

Safety Listing

The control is listed under the UL 353 standard for Limit Controls. A comparable listing is pending for CE.

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Troubleshooting Information

General

thermistor is measured. If desired this reading can be CXM board troubleshooting in general is best summa- compared to the chart shown in the thermistor section of this rized as simply verifying inputs and outputs. After this manual based upon the actual termperature of the thermistor process has been verified, confidence in board operation clip. An ice bath can be used to check calibration of a is confirmed and the trouble must be else where. Below thermistor if needed. are some general guidelines required for developing Outputs training materials and procedures when applying the The compressor relay is 24VAC and can be verified using a CXM control. voltmeter. The fan signal is passed through the board to the Field Inputs external fan relay. The alarm relay can either be 24VAC as shipped or dry contacts (measure continuity during fault) for All inputs are 24VAC from the thermostat.and can be varified using a volt meter between C and Y, G, O, W. use with DDC by clipping the J1 jumper. Electric heat outputs are 24VDC and require a voltmeter set for DC to See the I/O Reference table below. verify operation. When troubleshooting, measure from Sensor Inputs 24VDC terminal to EH1 or EH2 terminals. See the I/O Reference table below. All sensor inputs are 'paired wires' connecting each component with the board. Therefore continuity on Test Mode pressure switches, and the condensate switch can be Test mode can be entered for 20 minutes by shorting the test checked at the board connector. pins. For Diagnostic ease at the thermostat, the alarm relay The thermistor resistance should be measured with the will also cycle during test mode. The Alarm relay will cycle connector removed so that only the impedance of the on and off similar to the status LED to indicate a code representing the last fault, at the thermostat. Test mode can also be entered and exited by cycling the G input, 3 times within a 60 second time period. Table 5. Input/Output Reference Table

Connection R C Y W O G AL1 AL2 A BR BRG CC CCG HP LP FP1 FP2 RV CO 24VDC EH1 EH2 Input or Output I I I I O O O O O O O I I I I O I O O O Description 24 VAC 24 VAC (grounded common) Connect to thermostat - Y output call for compressor Connect to thermostat - W output call for Htg2 or Emerg Ht Connect to thermostat - 0 output call for reversing valve with cooling Connect to thermostat - G output call for fan Connect to thermostat fault light - 24VAC or dry alarm Alarm Relay 24VAC or dry Output for water solenoid valve - paralleled with compressor contactor coil Connection for blower relay-direct connect from G Blower relay common connection Connection for compressor contactor Compressor contactor common connection High Pressure Switch input terminals Low Pressure Switch input terminals Water Coil Freeze Protection Thermistor Input Air Coil Freeze Protection Thermistor Input Reversing Valve Output Terminals - direct connect from "O" Condensate overflow input terminals 24 VDC supply to electric heat module Output terminal for stage 1 electric heat Output terminal for stage 2 electric heat

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Troubleshooting Chart

Use the following troubleshooting flow chart to find appropriate troubleshooting strategies on the following pages for the CXM control and most water source heat pump applications.

Start

Did Unit Attempt to Start? Yes Did Unit Lockout at Start-up? No See " Unit short cycles" See " Only Fan Runs" Yes Unit Short Cycles? No Yes Only Fan Runs? No Only Compressor Runs? No

CXM Functional Troubleshooting Chart

No Check Main power (see power problems)

Yes

Check fault LED code on control board

No fault shown

See HP Fault See FP2 Fault

See LP/LOC Fault

See FP1 Fault

Replace CXM

See Condensate Fault

See Over/ Under Voltage

See " Only Comp Runs"

Yes

See " Does No not Operate in Clg"

Did unit lockout Yes after a period of operation? No Does unit operate in cooling? Yes

Unit is OK!

`See Performance Troubleshooting' for further help

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Functional Troubleshooting

Fault Main power Problems Htg Clg Possible Cause X X Green Status LED Off Solution Check Line Voltage circuit breaker and disconnect Check for line voltage between L1 and L2 on the contactor Check for 24VAC between R and C on CXM Check primary/secondary voltage on transformer Check pump operation or valve operation/setting Check water flow adjust to proper flow rate

HP Fault-Code 2 High pressure

X X X

Reduced or no water flow in cooling

Water Temperature out of range in Bring water temp within design parameters cooling Reduced or no Air flow in heating Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Dirty Air Coil- construction dust etc. Too high of external static. Check static vs blower table

X X X LP/LOC Fault-Code 3 Low Pressure/Loss of Charge FP1 Fault - Code 4 Water freeze protection X X X X FP2 fault - Code 5 Air Coil freeze protection X X X X X X X X

Air Temperature out of range in heating Overcharged with refrigerant Bad HP Switch Insufficient charge Compressor pump down at startup Reduced or no water flow in heating Inadequate anti-freeze level Improper freeze protect setting (30°F vs 10°F) Water Temperature out of range Bad thermistor Reduced or no Air flow in cooling Air Temperature out of range Improper freeze protect setting (30°F vs 10°F) Bad thermistor Blocked Drain Improper trap Poor Drainage

Bring return air temp within design parameters Check superheat/subcooling vs typical operating condition table Check switch continuity and operation. Replace Check for refrigerant leaks Check charge and start-up water flow Check pump operation or water valve operation/setting Plugged strainer or filter. Clean or replace. Check water flow adjust to proper flow rate Check antifreeze density with hydrometer Clip JW2 jumper for antifreeze (10°F) use Bring water temp within design parameters Check temp and impedance correlation per chart Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Too high of external static. Check static vs blower table Too much cold vent air? Bring entering air temp within design parameters Normal airside applications will require 30°F only Check temp and impedance correlation per chart Check for blockage and clean drain Check trap dimensions and location ahead of vent Check for piping slope away from unit Check slope of unit toward outlet Poor venting. Check vent location Check for moisture shorting to air coil Check power supply and 24VAC voltage before and during operation. Check power supply wire size Check compressor starting. Need hard start kit? Check 24VAC and unit transformer tap for correct power supply voltage

X X X Condensate Fault-Code 6 X X X X X X

X Over/Under VoltageCode 7 (Auto resetting) X X

Moisture on sensor Under Voltage

X

X

Over Voltage

Check power supply voltage and 24VAC before and during operation. Check 24VAC and unit transformer tap for correct power supply voltage

Unit Performance Sentinel-Code 8

X X

Heating mode FP2>125°F Cooling Mode FP1>125°F OR FP2< 40°F No compressor operation Compressor Overload Control board Dirty Air Filter Unit in 'Test Mode' Unit selection Compressor Overload Thermostat position Unit locked out Compressor Overload Thermostat wiring

Check for poor air flow or overcharged unit. Check for poor water flow, or air flow See 'Only fan operates' Check and Replace if necessary Reset power and check operation Check and Clean air filter Reset power or wait 20 minutes for auto exit. Unit may be oversized for space. Check sizing for actual load of space. Check and Replace if necessary Insure thermostat set for heating or cooling operation Check for lockout codes. Reset power. Check compressor overload. Replace if necessary. Check Y and W wiring at heat pump. Jumper Y and R for compressor operation in test mode.

No Fault Code Shown

X X X X X X X

X X X X X X X X X X X

Unit Short Cycles

Only Fan Runs

X X X X

Page 13

Functional Troubleshooting (cont.)

Only Compressor Runs X X X X Thermostat wiring Fan motor relay Check G wiring at heat pump. Jumper G and R for fan operation. Jumper G and R for fan operation. Check for Line voltage across BR contacts. Check fan power enable relay operation (if present) X X Unit Doesn't Operate in Cooling X X X Fan motor Thermostat wiring Reversing Valve Check for line voltage at motor. Check capacitor Check Y and W wiring at heat pump. Jumper Y and R for compressor operation in test mode. Set for cooling demand and check 24VAC on RV coil and at CXM board. If RV is stuck, run high pressure up by reducing water flow and while operating engage and disengage RV coil voltage to push valve. Check for 'O' RV setup not 'B' Check O wiring at heat pump. Jumper O and R for RV coil 'Click'.

X X

Thermostat setup Thermostat wiring

Performance Troubleshooting

Performance Troubleshooting Insufficient capacity/ Not cooling or heating properly X Htg Clg Possible Cause X X X Dirty Filter Reduced or no Air flow in heating Reduced or no Air flow in cooling Solution Replace or clean Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Too high of external static. Check static vs blower table Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Too high of external static. Check static vs blower table Check supply and return air temperatures at the unit and at distant duct registers if significantly different, duct leaks are present Check superheat and subcooling per chart Check superheat and subcooling per chart. Replace. Perform RV touch test Check location and for air drafts behind stat Recheck loads & sizing check sensible clg load and heat pump capacity Perform Scaling check and clean if necessary Check load, loop sizing, loop backfill, ground moisture. Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Too high of external static. Check static vs blower table X X X X X X X Reduced or no water flow in cooling Inlet Water too Hot Air Temperature out of range in heating Scaling in water heat exchanger Unit Overcharged Non-condensables insystem Restricted metering device Reduced water flow in heating Water Temperature out of range X Reduced Air flow in cooling Air Temperature out of range Insufficient charge Too high of air flow X X Poor Performance Too high of air flow Unit oversized Check pump operation or valve operation/setting Check water flow adjust to proper flow rate Check load, loop sizing, loop backfill, ground moisture. Bring return air temp within design parameters Perform Scaling check and clean if necessary Check superheat and subcooling. Reweigh in charge Vacuum system and reweigh in charge Check superheat and subcooling per chart. Replace. Check pump operation or water valve operation/setting Plugged strainer or filter. Clean or replace. Check water flow adjust to proper flow rate Bring water temp within design parameters Check for dirty air filter and clean or replace Check fan motor operation and airflow restrictions Too high of external static. Check static vs blower table Too much cold vent air? Bring entering air temp within design parameters Check for refrigerant leaks Check fan motor speed selection and airflow chart See 'Insufficient Capacity' Check fan motor speed selection and airflow chart Recheck loads & sizing check sensible clg load and heat pump capacity

X X X X X X X High Head Pressure X

X X X X X X X X

Leaky duct work Low refrigerant charge Restricted metering device Defective Reversing Valve Thermostat improperly located Unit undersized Scaling in water heat exchanger Inlet Water too Hot or Cold Reduced or no Air flow in heating

Low Suction Pressure

X X X X

X

X X Low discharge air temperature in heating High humidity X X X

*97B0003N01* 97B0003N01

7300 S.W. 44th Street Oklahoma City, OK 73179 Phone: 405-745-6000 Fax: 405-745-6058 www.climatemaster.com

ClimateMaster works continually to improve its products. As a result, the design and specifications of each product at the time of order may be changed without notice and may not be as described herein. Please contact ClimateMaster's Customer Service Department at 1-405-745-6000 for specific information on the current design and specifications. Statements and other information contained herein are not express warranties and do not form the basis of any bargain between the parties, but are merely ClimateMaster's opinion or commendation of its products.

© ClimateMaster 1998

Rev.: 10/00

Information

CXM AOM

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