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803809 Rev. 01  

Set Desired Temperature 

Press Cooler or Warmer key as applicable. Each push 
of the key increases or decreases the set point 
temperature by 1 degree, as applicable. 
   

Set Fan Mode 

Press Fan key to cycle through the fan settings as 
indicated by the small green circular LEDs. Select 
continuous High Speed fan, continuous Low Speed fan, 
or Intermittent Fan by selecting Auto. Auto cycles the 
fan on and off with the calls for heating or cooling. 
Auto also sets fan speed according to the amount of 
heating or cooling demanded. In Auto mode, the fan 
will start up periodically to establish airflow; air 
temperature will be sampled, and then the fan will shut 
off again if there is no demand. 
 

Disable Heating or Cooling, but Initiate Fan-Only 

Press On/Off key to turn off LED display. Press Fan 
key to cycle through the fan settings as indicated by the 
small circular LEDs. Select continuous High or Low 
speed. Do not select Auto, as it will turn the fan off.   
 

CONTROL AT THE WALL THERMOSTAT 

 

CONVERSION TO 24V REMOTE 
THERMOSTAT 

 
Except for the wall thermostat and thermostat cable, 
everything is included with the unit to field convert a 
keypad-operated unit to 24 Volt AC wall thermostat 
operation by qualified service personnel. Specific 
conversion instructions are detailed on the wiring 
diagram affixed to each particular unit to be converted. 
Conversion involves accessing the high voltage wiring 
compartment and changing a DIP switch setting on the 
electronic board. Once the DIP switch setting has been 
changed, operation will be in remote thermostat mode 
as soon as power is restored to the control.   
 

WARNING: 

The conversion procedure involves 

exposure to high voltage electrical circuits in the 
control box in order to make the necessary change to 
the DIP switch, and must be performed by qualified 
service personnel. Failure to do so could result in 
property damage, personal injury or death. Disconnect 
electric power to the unit before servicing. 

 
A factory-supplied 24 Volt wiring harness is provided 
with every unit to facilitate connection to the wall 
thermostat wiring. One end has a multi-pin connector 
which mates with a connector exiting the unit. The 
other end has preinstalled butt splice connectors, which 

play a dual role in insulating any unused connectors, 
and can also be used to make the wire connections for 
wires that are used.   
 
The final step is to apply the masking label provided, to 
cover up the keypad. The keypad and display will be 
disabled and no longer be available for control. The 
masking label markings instruct the user to go to the 
wall thermostat for controlling the unit. 

 

 
COMPATIBLE THERMOSTATS 

 
The features of the 24 VAC wall thermostat chosen 
will dictate the extent of the features available from the 
unit.  
Electric Heat / Cool units can accommodate the 
following thermostats in either manual or automatic 
changeover: 
 

 

Single Stage Heat/Cool, Single Speed Fan 

 

Single Stage Heat/Cool, Two Speed Fan 

 

Note: The thermostat selection must be verified to 
ensure its control logic will always energize a Fan 
output (G) on a call for heat – also known as an 
Electric Heat Type Thermostat.  

 
General: 
 
All the above can have single speed or two speed fan 
control. 
 
The wiring diagrams affixed to the units will guide the 
specific connection strategies for the particular 
thermostats used.  

 
 
THERMOSTAT LOCATION: 

 
Proper functioning of the thermostat depends on 
accurate room temperature sensing. Be conscious of 
locating the thermostat where temperatures near the 
thermostat are not representative of room temperature. 
For example, do not install the thermostat where it is 
subjected to direct sunlight, other sources of heat, or to 
cold drafts, including air discharged from a supply air 
register. A common error is forgetting to seal the hole 
in the wall where the thermostat cable passes through, 
directly behind the thermostat body. Air bleeding from 
behind the wall can drastically affect the temperature 
sensed by the thermostat.    

Summary of Contents for NFWC Series

Page 1: ...PACKAGED TERMINAL AIR CONDITIONER PTAC Cooling with Hot Water or Steam Heating INSTALLATION OPERATION MANUAL IMPORTANT READ AND SAVE THESE INSTRUCTIONS INSTALLATION AND WIRING MUST BE IN ACCORDANCE WITH CEC NEC AND LOCAL ELECTRICAL CODES ...

Page 2: ...or cooling during the building s construction stage To access the air filter first remove the grille cover from the heating subbase by rotating the two turn finger and thumb fasteners until the grille cover releases The unit front panel need not be removed The air filter is located directly below the heat exchange coil and slides out freely Always replace the grille cover after re inserting the fi...

Page 3: ...sleeve has a 1 8 per foot slope downward toward the outside to ensure proper water drainage out the back edge of the sleeve during overflow conditions The specified slope corresponds to a 1 8 bubble on a carpenter s level The wall sleeve must also be level from side to side HEATING SUB BASE The heating subbase contains a tube and fin heat exchanger that is configured for the use with hot water or ...

Page 4: ... tubes Always pipe the valve to the supply connection If the heating medium is hot water connect the valve outlet Supply to the lower connection and the Return water to the upper connection If the heating medium is steam connect the valve outlet Supply to the upper connection and the Return to the lower connection Route the steam or water source to the valve s inlet connection Install the piping v...

Page 5: ...t or debris that may have accumulated Replace any air seals that are damaged or missing if applicable Heating Cooling Chassis Installation 1 Locate the wall sleeve seal shipped with the unit and apply it to the top front flange of the wall sleeve running even with the bottom edge of the flange see illustration 2 Slide the chassis into the wall sleeve until firmly seated against the seals Push from...

Page 6: ...r in the bottom of the heating subbase so it is sure to sense true return air temperature and not air that has been heated by the heating coil Use the clamp provided to secure the bulb in place IMPORTANT To avoid damaging the indoor thermistor wire always remove the thermistor from the clamp holder before removing the chassis for service IMPORTANT Operating the unit without the filter in place can...

Page 7: ...to operate the fan and set fan speeds Auto Mode will cycle the fan on and off and determine the fan speed in conjunction with the heating or cooling demand Warmer Key Pressing the Warmer Key will cause the display to show the set point temperature for 3 seconds and then increases room temperature by 1 degree for every subsequent press of the key Cooler Key Pressing the Cooler Key will cause the di...

Page 8: ...ge personal injury or death Disconnect electric power to the unit before servicing A factory supplied 24 Volt wiring harness is provided with every unit to facilitate connection to the wall thermostat wiring One end has a multi pin connector which mates with a connector exiting the unit The other end has preinstalled butt splice connectors which play a dual role in insulating any unused connectors...

Page 9: ... to be ON or OFF and whether the fan is to run continuously or to cycle with heating or cooling demand Figure 2 Once a comfortable temperature setting is established no other adjustments are necessary except for fan speed which may or may not be adjustable on your particular thermostat CAUTION One side of the unit s 24 volt control system is grounded When wiring the thermostat care must be taken n...

Page 10: ... 22 The procedure to set the limits is as follows Depress the On Off key the F C key and the Warmer key simultaneously for 5 seconds to enter the limit setup mode The Warmer and Cooler keys will scroll through the R values indicated in the above table Once the desired R value has been obtained on the display press the On Off key to accept the change and then press it again to effect the change and...

Page 11: ...from the Chassis Air Outlet by removing the screw located under the control door The Duct Plenum can now be installed Insert the Duct Plenum tabs into the slots provided in the Chassis Enclosure based on the direction you require the air discharge On the opposite end of the tabs there will be an existing screw location Use the screw removed previously to secure the Duct Plenum to the Chassis Air O...

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