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14 

HOT WATER COIL PIPING 

 
The water coil connections are: 
 
 ½”  nominal  (5/8”OD)  copper  on  all  models  with  internal  pump  factory 
installed.   
 
An air purge valve must be installed between the air handler outlet and the 
return water isolation valve. 
 
Flow stickers indicate the proper water flow direction. 
 
Isolation  valves  must  be  placed  in  both  the  hot  water  supply  and  return 
water lines to the hot water tank so that the CAH unit may be serviced or 
repaired  without  causing  excessive  water  discharge.    All  piping  between 
the  water  heater  and  the  air  handler  should  be  copper  and  should  never 
exceed  100  feet  of  total  equivalent  piping.    On  runs  over  60  feet 
equivalent, it is recommended that ¾” nominal (7/8” OD) piping be used 
to  prevent  excessive  system  pressure  drop.    Vertical  rises  should  be  kept 
as  short  as  possible.    Where  extended  runs  or  large  vertical  rises  are 
required (greater than 5  feet) it is  recommended  that the installer consult 
the factory for proper installation practices. 
 
NOTE:   It  is  not  recommended  to  locate  water  piping  in  unconditioned 
spaces. 
 
All  copper  joints  in  the  water  lines  must  be  made  with  low  temperature, 
non-lead  solder.    Due  to  the  use  of  domestic  hot  water  in  the  units,  all 
local  and  national  plumbing  codes  relating  to  potable  water  must  be 
complied with for proper installation. 

 

 

Summary of Contents for CAH 33-44-50

Page 1: ...CAH SERIES INSTALLATION MAINTENANCE MODELS CAH 33 44 50 CAH 49 54 70 ...

Page 2: ...S 8 SUPPLY AND RETURN DUCT REQUIREMENTS 9 THERMOSTAT SELECTION 12 SELECTING FAN SPEEDS 12 BLOWER MOTOR WIRE SELECTION CHART 13 HOT WATER COIL PIPING 14 OPERATION AND MAINTENANCE 15 INITIAL START UP 15 AIR FILTER 18 BLOWER MOTOR 18 CIRCULATION PUMP REPLACEMENT 18 PUMP CONTROL 19 SEQUENCE OF OPERATION IN HEATING MODE 19 TROUBLESHOOTING 20 MOST LIKELY PROBLEMS AND CAUSES 20 FAULTY CIRCUIT BOARD 22 WI...

Page 3: ...3 DIMENSIONS MODEL A B C D E F CAH 33 44 50 17 23 35 5 12 18 11 CAH 49 54 70 21 25 23 43 75 16 18 17 ALL MEASUREMENTS IN INCHES ...

Page 4: ... 58 000 1200 CFM 65 000 1600 CFM 76 000 POWER SUPPLY 120 VAC 1PH 60HZ 120 VAC 1PH 60HZ TOTAL AMPS 5 5 9 5 MAXIMUM FUSE 15 15 TRANSFORMER 30 VA 30 VA BLOWER MOTOR 1 3HP ECM 3 4HP ECM PUMP 3 SPEED 3 SPEED WATER CONNECTIONS 1 2 1 2 FILTER SIZE 12 x 20 x 1 18 x 20 x 1 OUTPUT BTU 3GPM OUTPUT BTU 4GPM ...

Page 5: ...lude factory installed valves Others must be field installed Follow the instructions of the water heater manufacturer and local codes when installing the T P valve Do Not alter the water heater controls dip tube relief valve fitting etc Do Not install unit or connecting piping in any manner except as shown in this instruction manual Do Not install a DX cooling Coil in close proximity to the Hot Wa...

Page 6: ...n such cases the Temperature and Pressure Valve of the water heater may weep OR relieve due to expansion of the water when heated Note that this would occur even if this air handler were not installed A small diaphragm type thermal expansion tank will normally eliminate the weeping condition Please read and follow the manufacturer s instruction for installation of such tanks Further Note The above...

Page 7: ...ooling The freeze stat typically opens at 38 F closes at 60 F and is wired to interrupt the A C compressor operation Mount the freeze stat on the suction line of the cooling coil and wrap with cork tape covering both the stat and the suction line If the freeze stat is not securely fastened and insulated to the suction line the compressor may not shut off if the evaporator coil freezes up ...

Page 8: ...pplications and all models comply with zero clearance installation to combustible materials Sufficient clearance must be provided to allow access to electrical controls and to the blower motor assembly for servicing This clearance distance should be approximately the same as the depth of the fan coil unit at a minimum LINE AND CONTROL WIRING REQUIREMENTS All wiring must meet with local and nationa...

Page 9: ...d on the fan coil unit If there is no ducted return installation codes may limit the unit to installation only in a single story residence Ducting should normally be sized for external static pressures of 0 15 to 0 3 inches H2O total Figure 1 Figure 2 Figure 1 Correct way to duct plenum off of air handler whenever possible in a new installation Figure 2 Incorrect way to duct plenum off of air hand...

Page 10: ...10 Figure 3 Figure 4 Figure 3 Correct way to install duct work Figure 4 Incorrect way to install duct work ...

Page 11: ...11 Typical Air Handler Schematic ...

Page 12: ...e settings are selected by moving the wires on the motor tap selection tree located in the blower mounted electrical box Use the Blower Motor Wire Selection Chart in this manual to select the proper wires for your application HEAT COOL FAN SPEED select the appropriate motor tap wire to plug into this terminal This is the speed the motor will run for both heating and cooling LOW CONTINUOUS FAN sele...

Page 13: ...EED LOW CONTINUOUS SPEED YELLOW TRACE 600 CFM 1000 CFM BLUE TRACE 800 CFM 1200 CFM PURPLE TRACE 800 CFM BOOST 1200 CFM BOOST BLACK TRACE 1000 CFM 1600 CFM EXAMPLE Model CAH 33 44 50 Blue Trace wire onto the heat cool fan speed Terminal Unit will run at 800 cfm for both heating and cooling 0 4 external static ...

Page 14: ...should be copper and should never exceed 100 feet of total equivalent piping On runs over 60 feet equivalent it is recommended that nominal 7 8 OD piping be used to prevent excessive system pressure drop Vertical rises should be kept as short as possible Where extended runs or large vertical rises are required greater than 5 feet it is recommended that the installer consult the factory for proper ...

Page 15: ...rated in heating mode until the user supplied installed isolation valves have been opened and the hot water coil and hot water lines have been purged of air Heating Mode Initial Operation 1 Fill the water heater refer to water heater instruction Open a domestic hot water faucet while filling the water heater to vent the air When the tank is full and all of the air is purged close the faucet 2 Igni...

Page 16: ...supply and return isolation valves to allow water to flow through the system Note it will often require purging several gallons of water so either have a bucket available or an alternate means of discarding the water 4 Switch the room thermostat to the heat position and raise the temperature setting to a position approximately five to ten degrees above the room temperature Note The door switch mus...

Page 17: ... S and DON TS section for mixing valve requirement for higher temperatures depending upon unit selection temperature Allow the system to operate long enough for all temperatures to stabilize and recheck temperature setting Remember that the domestic supply water temperature should be kept to 120 F or lower by means of an appropriate mixing valve ...

Page 18: ...sition terminal strip on the blower mounted electrical box Unplug the power supply MOLEX terminal from the top of the blower mounted electrical box Remove the two blower mount screws and slide blower and motor from the unit CIRCULATION PUMP REPLACEMENT Disconnect electrical power before servicing the unit To replace the circulating pump close the isolation valves and relieve the water pressure fro...

Page 19: ...NCE OF OPERATION IN HEATING MODE 1 When the thermostat calls for heat W the pump and blower motor will run at the selected operating fan speed 2 When the thermostat ends the call for heat W the pump and blower turn off The blower will continue running at the continuous low speed if the thermostat is set to FAN ON Note Upon powering up the air handler circuit board starts a 15 second initialization...

Page 20: ... the water circuit Purge air from the system as described under start up procedure Insufficient or No Heat 1 Air may still be trapped in heating loop Purge air from the system as described under start up procedure 2 Water heater thermostat not turned up high enough Remember higher than 120 F mixing valve for domestic service 3 Inlet and outlet piping connection at the air handler may be reversed S...

Page 21: ...stalled and firmly plugged into the motor Check voltages in the cables 3 Check door switch depressed power supply and thermostat lines are wired properly Refer to the electrical diagram supplied with each air handler 4 Check the voltages at motor plugs 120VAC and 24VAC 5 There may be a faulty TAP on the motor Select a different speed on the motor tap selection tree Refer to the Selecting Fan Speed...

Page 22: ...ted check that the board fuse is not blown and replace if necessary If there is malfunction a temporary circuit board bypassed can be utilized until a replacement circuit board is installed With the power off remove the fuse from the circuit board Move the PUMP wire Orange Black stripe and the High Fan wire White Red Stripe to the two extra W terminals This will allow the pump and blower to run wi...

Page 23: ...23 WIRING DIAGRAMS ...

Page 24: ...24C T5 X PTRA 1C 24C T5 X TRANSFORMER PU30va PU30va MOTOR CAH37 1 3ECM CAH58 3 4ECM DOOR SWITCH CARLING TA20B CARLING TA20B COIL BC9061 BC7923FX HOUSING DC1016 600 5 DC1020 800 5 PUMP UPS15 58RU UPS15 58RU CHECK VALVE 96806141 96806141 CONTROL BOARD PT ECB V1 0 PT ECB V1 0 ...

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