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APPLICATION, OPERATION
& MAINTENANCE MANUAL
DXM2 Digital
Heat Pump Controller
Heat Controller, Inc. • 1900 Wellworth Ave. • Jackson, MI 49203 • (517)787-2100 • www.heatcontroller.com
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. Table of Contents DXM2 Electronic Heat Pump Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 DXM2 Physical Dimensions & Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 DXM2 Layout and Co
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Electronic Heat Pump Controls DXM2 OVERVIEW Grounding The manufacturer’s next generation control board, DXM2, The control board must be grounded from one of the C is the geothermal industry’s fi rst two-way communication. terminals. The DXM2 electronic control is a robust, microprocessor Basic Control Features based heat pump controller that is advanced and feature- • Single or two–stage compressor cont
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Factory Use 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 COH COM Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Physical Dimensions & Layout 5" P4 C Gnd B- A+ 24V (240Vac) (240Vac) P1 N.C. N.O. R P5 Y1 N.O. Com Y2 Fan Enable Fan Speed W O G P8 R 12V Test P12 C IN AL1 OUT Gnd NC P2 AL2 R Micro 1 NSB JW1 HP U1 Alarm Relay HP C LP Fault Status ESD LP 6 1/2" 7" OVR LT1 LT1 H LT2 Factory low Off On A voltage molex LT2 JW3 connection for RV
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Factory Use Compressor Discharge temperature Entering Hot water Temperature Leaving air temp Leaving 1 2 3 4 5 6 7 8 water temp Entering water temp 1 2 3 4 5 6 7 8 Variable 1 2 3 4 speed pump COH COM Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Layout and Connections Communicating Service tool stat connection connection P4 C Gnd B- A+ 24V (240Vac) (240Vac) P1 N.C. N.O. R P5 Y1 N.O. Com Y2 Fan Enable Fan Speed W Test Button Con
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Controls THERMOSTAT COMPATABILITY - IT IS STRONGLY RECOM- setting for LT1 of 30°F or 10°F [-1°F or -12°C] (refrigerant MENDED THAT A COMMUNICATING THERMOSTAT (7602-443) temperature). BE USED WITH GEOMAX COMMUNICATING SYSTEMS FOR: Not Clipped = 30°F. Clipped = 10°F. 1. Four-wire connections between the thermostat, compres- Alarm Relay Setting - Jumper 1 (JW1-AL2 Dry) provides sor section (HTS), and air
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Controls On = Heat Pump. Off = Heat/Cool. DIP Package #3 (S3) DIP 1.4: Thermostat Type (O/B) - Provides selection of DIP Package #3 is 4 position and provides the following thermostat type. Heat pump thermostats with “O” output on setup selections. with Cooling or “B” output on with Heating can be selected. DIP 3.1: Communications confi guration: Provides selection On = HP Stat with O output with cooling
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Controls SAFETY FEATURES CAUTION! The following safety features are provided to protect CAUTION! Do not restart units without inspection and the compressor, heat exchangers, wiring and other remedy of faulting condition. Equipment damage may occur. components from damage caused by operation outside of design conditions. the DXM2 is in Lockout Mode, and the W input becomes Anti-Short Cycle Protectio
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Controls compressor run cycle. When the Test mode is active, the When the Test mode is active, the Fault LED will display a Fault LED will display a fault code of 5 for a LT2 fault. fault code of 9 for a Swapped Thermistor fault. Fault Code 6: Condensate Overfl ow - The Condensate Fault Code 10: ECM Blower Fault – When operating Overfl ow sensor must sense overfl ow levels for 30 an ECM blower, there are
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Controls Note: The compressor will have a 5-minute anti-short when the Heating Stage 1 demand is removed. The cycle delay at power-up. selected Fan output(s) will turn off after the selected heating blower off delay, and the control then reverts to Standby/Fan Only - In Standby Mode, the compressor will Standby Mode. If there is a Master/Slave situation or a be off. The selected fan output(s) and
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Controls will change to the appropriate Heating Stage 3 airfl ow. With continuing Heating Stage 3 demand, EH2 will turn on Blower Confi gurations – The DXM2 may be confi gured after 10 minutes. EH1 and EH2 are turned off immediately to operate several different blowers and blower when the Heating Stage 3 demand is removed, and the confi gurations. The confi gurations include: control reverts to Heatin
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Controls airfl ow for the current operating mode. For the fi rst Digital Night Setback – If an Accessory relay is confi gured 30 seconds of blower operation, the target airfl ow will for Digital NSB, the Accessory relay will be on any time the be 50% of the normal target airfl ow. For the next 90 NSB input is connected to Ground “C”. seconds of blower operation, the target airfl ow will Note: If there are n
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Controls to the compressor output. All other heat pump operating go to Night Setback Setpoints. Stated differently, when modes will operate normally, and the accessory relay will confi gured for Digital NSB Mode, the Accessory Relay be off in all other operating modes. directly tracks the NSB input. Thermostat Inputs – Table 5 shows the resulting demand Note: Digital Night Setback feature requires a f
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Controls counterpart to DIP1.5, meaning if H is connected to setback is not connected and NSB is connected to Ground 24VAC then the selected fan outputs will operate using “C”, then if OVR is momentarily connected to 24VAC dehumidifi cation speeds and airfl ow settings for cooling. If (minimum 1 second) then the OVR input is recognized H is not connected to 24VAC then the selected fan outputs as a N
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Controls Under Voltage, UPS or Swapped LT1/LT2) 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. See Table 3: “LED and Alarm Relay Operation”. Communications The DXM2 has a single RS485 communications port that provides communication capabilities for communicating thermostats or connecting w
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. DXM2 Service & Application Notes Pressure Switches Table 9: Nominal resistance at All pressure switches are designed to be normally closed various temperatures during normal operating conditions, and to open upon fault. Resistance Resistance Temp (ºC) Temp (ºF) Temp (ºC) Temp (ºF) (kOhm) (kOhm) Condensate Sensor – The Condensate Sensor input will -17.8 0.0 85.34 55 131.0 2.99 fault upon sensing impedance
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual DXM2 Service & Application Notes DXM2 Thermostat Details THERMOSTAT COMPATABILITY - IT IS STRONGLY RECOM- MENDED THAT A COMMUNICATING THERMOSTAT (7602-443) BE USED WITH GEOMAX COMMUNICATING SYSTEMS FOR: 1. Four-wire connections between the thermostat, compres- sor section (HTS), and air handler (WDG). 2. Confi guring, monitoring and diagnosing the system in PLAIN ENGLISH on the thermostat. Thermostat Compati
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. Basic Troubleshooting Information General Troubleshooting Basic DXM2 board troubleshooting in general is best summarized as simply verifying inputs and outputs. After this process has been verifi ed, confi dence in board operation is confi rmed and the trouble must be else where. Below are some general guidelines required for developing training materials and procedures when applying the DXM2 Control. DXM2
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Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual Advanced Troubleshooting and Confi guration Information General Unit Confi guration – Selections under the Unit To properly confi gure and troubleshoot advanced control Confi guration menu are normally set at the factory as a features, and to aid in troubleshooting basic control normal part of the manufacturing and test process. This features, a communicating thermostat or diagnostic tool menu allows the confi
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Application, Operation, & Maintenance Manual DXM2 UNIT CONTROLS Heat Controller, Inc. Advanced Troubleshooting and Confi guration Information Service Mode The Service Mode provides the installer with several functions for troubleshooting, including Manual Operation, Control Diagnostics, Control Confi guration, and Fault History. Manual Operation – The Manual Operation mode allows the installer to bypass normal thermostat timings and operating modes, to directly activate the thermostat input
