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CONTROL SYSTEM

29

CONTROL BOARD

The heart of the control system is the Control Board which is a printed circuit board (PCB) installed inside the control box. See Figure 

13 below, Figure 14 on page 3

0

 and the Wiring Diagrams on page

s

 

32 to 

36.

The Control Board is powered by 24 VAC from the transformer. The F4 fuse on the Control Board protects the secondary winding of 

the transformer.
The Control Board has four (4) proving circuits that must be closed by either a factor-installed jumper wire or the dry contacts in an 

external control to enable HPWH operation. The Control Board also has one (1) thermostat circuit that is factory wired to the HPWH 

Terminal Strip. The factory supplied Digital Tank thermostat  (see page 19) or a field supplied standard tank thermostat is wired to 

this thermostat circuit to regulate water temperature in the storage tank.  See Figure 1

5

 on page 

37

 and Figure 1

6

 on page 

38

SERVICE NOTE: All five (5) of these circuits must be closed circuits or the HPWH will not operate. See items 1-5 in Figure 13 below. 

If the HPWH unit does not begin a heating cycle within 

5 minutes 

(allowing time for the anti-short-cycle timer) after power is applied 

ensure the thermostat is calling for heat (closed contacts). is unresponsive when power is applied 

PRESSURE SWITCHES

The Control Board monitors two refrigerant pressure switches, a high and a low pressure switch. If the contacts on either switch open 

during a heating cycle the control system will lockout and the compressor will be disabled. The blower and the pump will continue to 

operate as long as a call for heat is present. The cause of the pressure switch contacts opening must be corrected and the control 

system must be reset before the HPWH will resume compressor operation. See Table 1

1

 for pressure switch activation pressures.

Low and High pressure switch LED lights on the Control Board will be energized during this fault condition as a diagnostic aid to 

indicate which switch has cased the fault condition. See Figure 14 on page 3

0

. The low pressure switch is on a time delay (Time 

Safety By-Pass) to prevent nuisance lockouts during start up when the return (inlet) water may be below . This delay is set for 300 

seconds from the factory.

TABLE 

11

MODEL

LOW PRESSURE SWITCH

Normally Open - Close On Rise

HIGH PRESSURE SWITCH

Normally Closed - Open On Rise

AWH-35 - AWH-170

Contacts Close

Contacts Open

Contacts Close

Contacts Open

35 PSI (241 kPa) ± 5%

15 PSI (103 kPa) ± 5%

250 PSI (1,724 kPa) ± 15%

350 PSI (2,413 kPa) ± 15%

CONTROL BOARD

LP Switch

Remote Alarm

(dry contact)

To HP

Switch

From Transformer

24 VAC Power Supply

To LP Switch

Time Safety

HP Switch

Remote Alarm

(dry contact)

2

4

ON/OFF

Switch

To HPWH Terminal Strip

Tank Aquastat (thermostat)

Push

Button

Reset

To Pump Contactor

To Blower Contactor

To Compressor Contactor

Remove the jumper when Phase

Monitor is used.

1

1

Remove the jumper when Push Button

Reset (NC contact) is used.

2

Remove the jumper when Compressor

Overload Module is used.

3

3

Remove the jumper when ON/OFF

Switch is used.

4

NOTE: 1-4 are all proving circuits for external

control dry contacts. These circuits must be

closed to enable operation. If any of these

circuits are open HPWH operation will be

disabled; compressor, blower and pump

will not run. Jumpers must be installed for

proving circuits 1-4 when external controls

are not in use. Tank Aquastat (thermostat)

must be connected to #5.

Figure 13

Summary of Contents for AWH-35

Page 1: ...70 SERIES 100 INSTALLATION OPERATION SERVICE MAINTENANCE LIMITED WARRANTY 820 SW 41st Street Renton WA 98057 Read and understand this instruction manual and the safety messages herein before installin...

Page 2: ......

Page 3: ...ank Thermostat Wiring 37 Standard Tank Thermostat Wiring 38 High Ambient Air Kit Wiring 39 Building Recirculation Pump Wiring Diagram 40 PIPING DIAGRAMS 41 LIMITED WARRANTY 47 TABLE OF CONTENTS 3 SAFE...

Page 4: ...possible injury or death WARNING indicates a potentially hazardous situation which if not avoided could result in injury or death CAUTION indicates a potentially hazardous situation which if not avoi...

Page 5: ...er procedures or the use of non approved refrigerants refrigerant substitutes or refrigerant additives could result in death or serious injury or equipment damage Explosion Hazard Do not use oxygen to...

Page 6: ...G APPLIANCE INTRODUCTION 6 Detailed installation diagrams are in this manual These diagrams will serve to provide the installer with a reference for the materials and suggested methods of piping IT IS...

Page 7: ...flowing through the tubes and air flowing across the fins The Blower moves ambient air from the installed space or air ducted to the HPWH from another location across the fins of evaporator coil The r...

Page 8: ...IQUID COMPONENT WATER CIRCUIT A WATER INLET B WATER PUMP C HEAT EXCHANGER CONDENSER D WATER OUTLET WARM RETURN AIR IN COOL SUPPLY AIR OUT ACCUMULATOR COMPRESSOR CONDENSER HEAT EXCHANGER REFRIGERANT TO...

Page 9: ...8 660 AWH 115 33 1 113 000 89 000 7 4 4 2 3200 23 1 5 63 38 42 5 8 665 AWH 140 41 6 142 000 110 000 9 2 3 9 3800 28 2 0 63 38 42 5 8 725 AWH 170 50 1 171 000 133 000 11 1 3 9 4900 34 2 0 75 46 42 5 8...

Page 10: ...ating range the HPWH unit s Ambient Air Limit Thermostat will discontinue heating operation until the entering air temperature returns to this operating range See Figure 15 on page 37 High Ambient Air...

Page 11: ...ssary to access an adequate or greater source of heat for optimal efficiency See Building Air Pressure Air Flow and Ducting on page 19 CLEARANCES To ensure optimal performance a minimum of 30 inches c...

Page 12: ...this could result in death serious bodily injury or property damage The load current rating and the overcurrent protection for these conductors shall not exceed 15 amperes for 14 AWG 20 amperes for 1...

Page 13: ...demand of the application a Mixing Valve should be installed upstream from the building fixtures or at the hot water taps to further reduce system water temperature Mixing valves are available at plum...

Page 14: ...ause brain damage or death Always read and understand instruction manual Breathing Hazard Carbon Monoxide Gas The supply outlet air from a HPWH installed in a garage or a unit drawing return inlet air...

Page 15: ...unless spreader bars are furnished and used as depicted in Figure 4 and Figure 5 The side panels and roof of the unit are not constructed to handle significant force from the sides or above The HPWH...

Page 16: ...H in new construction the following critical points must be observed The HPWH unit 1 Must be installed indoors 2 Should be installed near a floor drain for condensate removal 3 The HPWH storage tank a...

Page 17: ...S 1 This HPWH unit is not designed to supply hot water directly to hot water fixtures The HPWH unit must be installed with a separate storage tank as shown in the water piping diagrams in this instruc...

Page 18: ...NK PRE HEAT CONFIGURATION When water temperatures above 140 F 60 C are required the HPWH and storage tank are piped in series upstream with a backup water heater See Water Temperature on page 10 The b...

Page 19: ...he building structure Gas and carbon monoxide detectors are available Breathing carbon monoxide can cause brain damage or death Always read and understand instruction manual Breathing Hazard Carbon Mo...

Page 20: ...r entering the HPWH unit the supply air may not be suitable for supplemental space cooling purposes The air temperature drops approximately 12 F to 20 F 7 C to 11 C as it flows through the HPWH unit I...

Page 21: ...12 14 16 18 20 22 24 MODEL CFM EXT in WG MAXIMUM EQUIVALENT LENGTH FEET AWH 35 1040 0 35 6 18 45 93 185 AWH 55 1650 0 35 3 8 18 40 77 137 AWH 75 2150 0 35 5 11 23 47 83 139 AWH 100 3200 0 35 3 6 14 26...

Page 22: ...t Water Temperature on page 10 See Figure 7 and Figure 8 on page 18 14 On two tank preheat piping configurations ensure the cold INSTALLATION CHECKLIST 22 water supply is not connected to the back up...

Page 23: ...mentioned above call the toll free technical support phone number on the back cover of this manual for further assistance 6 When all of the above procedures are complete adjust the tank temperature c...

Page 24: ...buttons to adjust to the desired differential set point 3 When complete press the SET button to save the change 4 The operating mode of the thermostat will be shown on the LED display next as CoL for...

Page 25: ...performing any maintenance on the blower assembly disconnect all power to the unit and follow the prescribed lock out tag out procedure Inspect and tighten all bearing collar and wheel set screws afte...

Page 26: ...plication and usage instructions 5 Allow the unit to dry thoroughly 6 If necessary apply an anti microbial agent on the insulation per the instructions provided on the product label 7 Discard collecte...

Page 27: ...t pump reduce piping or add booster pump clean heat exchanger with a mild acid wash open all shut off valves Heat pump is not running low pressure fault 1 Room temperature below 50 F 2 Blower not oper...

Page 28: ...in the inlet and outlet water piping connected between the HPWH unit and the storage tank On new installations ensure the maximum equivalent feet of inlet and outlet piping was not exceeded This is th...

Page 29: ...ent The cause of the pressure switch contacts opening must be corrected and the control system must be reset before the HPWH will resume compressor operation See Table 11 for pressure switch activatio...

Page 30: ...e containing a relay or triac transformer and several electronic components Leads from the internal motor sensors are connected to the module As the motor temperature rises or falls the resistance als...

Page 31: ...nits TABLE 13 ABBREVIATION DESCRIPTION WIRING NOTES PM Phase Monitor Factory If installed PC Pump Contactor Factory Load pump if installed BC Blower Contactor Factory CC Compressor Contactor Factory H...

Page 32: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC SINGLE PHASE 60 HZ 32...

Page 33: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC THREE PHASE 60 HZ AWH 35 AWH 55 and AWH 75 only 33...

Page 34: ...UNIT WIRING DIAGRAMS FUSE SIZES 208 230 VAC THREE PHASE 60 HZ only 34...

Page 35: ...UNIT WIRING DIAGRAMS FUSE SIZES 460 VAC THREE PHASE 60 HZ 35...

Page 36: ...UNIT WIRING DIAGRAMS FUSE SIZES 460 VAC THREE PHASE 60 HZ only 36...

Page 37: ...AIR TEMPERATURE SENSOR RANCO DIGITAL THERMOSTAT PART ETC 212000 000 24V COM NC NO C NC C NO DIGITAL TANK THERMOSTAT FULL GAUGE MODEL MT511Ri NOTE TANK TEMPERATURE SETTING MUST NOT EXCEED 140 F 60 C C...

Page 38: ...ATION NOTES 1 Configure stage 1 for cooling 2 Configure stage 2 for heating 3 Set cooling set point at 50 F 4 Set heating set point 95 F 5 Set cooling differential to 10 F 6 Set heating differential t...

Page 39: ...e on fall WHITE Close RED Close BLACK Close C NO NC 1 2 3 4 5 6 7 8 9 0 1 1 1 2 1 OUTPUT THERMOSTAT TERMINAL STRIP HPWH TERMINAL STRIP AMBIENT AIR LIMIT THERMOSTAT CONFIGURATION NOTES 1 Configure stag...

Page 40: ...NK FIELD SUPPLIED LINE TEMPERATURE CONTROL INSTALLED IN THE CIRCULATING LOOP RETURN LINE CIRC PUMP MOTOR L1 HOT L2 NEUTRAL 120 VAC POWER NOTE USE SEPARATE 120 VAC POWER SUPPLY FOR PUMP CIRCUIT Figure...

Page 41: ...URE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP DRAIN WYE STRAINER FULL PORT BALL VALVE TEMPERATURE GAGE CHECK VALVE TANK OR LINE TEMPERATURE CONTROL WARNING THIS DRAWING SHOWS SUGGESTED PIPIN...

Page 42: ...E TEMPERATURE GAGE CHECK VALVE WARNING THIS DRAWING SHOWS SUGGESTED PIPING CONFIGURATION AND OTHER DEVICES CHECK WITH LOCAL CODES AND ORDINANCES FOR ADDITIONAL REQUIREMENTS TANK OR LINE TEMPERATURE CO...

Page 43: ...N COLD WATER SUPPLY LINE THERMOSTAT NOTE CONNECT BUILDING RECIRC RETURN TO INLET OF BACKUP WATER HEATER WHEN PRESENT TANK THERMOSTAT PIPE T P TO OPEN DRAIN RETURN WATER INLET PURGE VALVE SUPPLY WATER...

Page 44: ...ULL PORT BALL VALVE TEMPERATURE GAGE CHECK VALVE TANK OR LINE TEMPERATURE CONTROL WARNING THIS DRAWING SHOWS SUGGESTED PIPING CONFIGURATION AND OTHER DEVICES CHECK WITH LOCAL CODES AND ORDINANCES FOR...

Page 45: ...AND ORDINANCES FOR ADDITIONAL REQUIREMENTS LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP DRAIN WYE STRAINER FULL PORT BALL VALVE TEMPERATURE GAGE CHECK VALVE TANK OR...

Page 46: ...ion of it in a modified form will void this warranty 4 SERVICE REPAIR AND EXPENSE Under this limited warranty the warrantor will provide only a replacement heat pump water heater or part thereof The o...

Page 47: ...talled Dealer s Name Dealer s Address Phone No City and State Zip Fill in the following for your own reference Keep it Registration is not a condition of warranty The model and serial number are found...

Page 48: ...500 Tennessee Waltz Parkway Ashland City TN 37015 Technical Support 800 527 1953 Parts 800 433 2545 Fax 800 644 9306 www hotwater com...

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