EMERSON 1F75P-21NP PTAC Thermostat Hardwired with Common Instruction Manual
- June 17, 2024
- Emerson
Table of Contents
EMERSON 1F75P-21NP PTAC Thermostat Hardwired with Common
SPECIFICATIONS
Electrical Rating
- Input-Hardwire………………………………. 20 to 30 VAC, NEC Class II, 50/60 Hz
- Terminal Load……………………………………. 1.5 A per terminal, 2.5A maximum for all terminals combined
- Setpoint Range………………………………….. 60°F to 85°F (16°C to 29°C)
- Rated Differentials (@ 6°F/ Hr): Fast Med Slow
- Heat Pump (Heating)………………………. 0.9°F 1.2°F 1.7°F
- Heat Pump (Cooling)………………………. 0.9°F 1.2°F 1.7°F
- Auxiliary Heat………………………………… 0.5°F 0.75°F 1.9°F
- Operating Ambient…………………………….. 32°F to +105°F (0° to +41°C)
- Display Temperature Range…………………… 32°F to +99°F (0 to 37°C)
- Operating Humidity……………………………. 90% non-condensing maximum
- Shipping Temperature Range……………….. -20°F to + 150°F (-29° to +65°C)
- Thermostat Dimensions………………………. 3-3/4” H x 6” W x 1-1/8” D
THERMOSTAT INSTALLATION
WIRING
Refer to the equipment manufacturer’s instructions for specific system wiring
information. After wiring, see INSTALLER MENU for proper thermostat
configuration. The wiring table shown is for typical systems and describes the
thermostat terminal functions.
| Terminal Designations | Terminal Function |
|---|---|
| GL | Low-Speed Fan Relay |
| R | Power (24V) |
| O/B | Changeover Terminal-Energized in Cool (O) or Heat (B) for Heat Pump. |
| Y | Heat and Cool Mode 1st Stage Compressor |
| GH | High-Speed Fan Relay |
| W | Heat Mode – 2nd stage (Electric) |
| C | Common wire for 24V |
Precautions
- Do not exceed the specification ratings.
- All wiring must conform to local and national electrical codes and ordinances.
- This control is a precision instrument and should be handled carefully. Rough handling or distorting components could cause the control to malfunction.
WARNING
- Do not use on circuits exceeding specified voltage. Higher voltage will damage control and could cause shock or fire hazards.
- Do not short out terminals on the gas valve or primary control to test. Short or incorrect wiring will burn out the thermostat and could cause personal injury and/or property damage.
CAUTION
To prevent electrical shock and/or equipment damage, disconnect electrical
power to the system at the main fuse or circuit breaker box until installation
is complete.
Instructions: To convert
the system from PTHP to PTAC, cut the jumper wire located on the back of the
thermostat. Change menu item #20 from default HP to AC.
Note: Menu item #32 will not be displayed in AC mode.
O/B Terminal Switch
The O/B switch on this thermostat is factory set to the B position. This will
accommodate heat pump applications, which require the changeover relay to be
energized in Heat. If the heat pump is installed requires an O terminal to
energize the changeover relay in Cool, the O/B switch must be moved to the O
position.
INSTALLER MENU
To access the INSTALLER’S MENU set the system switch to the OFF position and then press and hold the temperature and buttons for 3 seconds. The display will show item 20 in the table below. Use the temperature and buttons by pressing them simultaneously to navigate through menu items. Press or to change a menu setting.
TEST EQUIPMENT
Turn on the power to the system.
Fan Operation
- Move the fan switch to the Low position. The blower should begin to operate at low speed.
- Move the fan switch to the Auto Low position. The blower should stop immediately.
- Move the fan switch to the High position. The blower should begin to operate at high speed.
- Move the fan switch to the Auto High position. The blower should stop immediately.
Heating System
- Move the System Switch to the Heat position.
- Press to adjust the thermostat setting to 1° above room temperature. The heat pump system should begin to operate and the thermostat will indicate Heat On.
- Press to adjust the thermostat setting to 3° above room temperature. The auxiliary heat should begin to operate and the thermostat will indicate Heat On Auxiliary.
- Press to adjust the thermostat setting to 1° below room temperature. The heating system should stop operating and the thermostat should indicate Heat.
Cooling System
- Move the System Switch to the Cool position.
- Press to adjust the thermostat setting to 1° below room temperature. The blower should come on immediately, followed by cold air circulation. The thermostat will indicate Cool On. There can be up to a 5-minute delay. (see INSTALLER MENU, item 50)
- Press to adjust the thermostat setting to 1° above room temperature. The cooling system should stop operating and the thermostat will indicate Cool.
Note: The default position for the compressor lockout is OFF in the INSTALLER menu, item 50. When the compressor lockout is turned ON Starting Soon will be visible on the display. If Starting Soon is shown on the display, the compressor lockout feature is operating. There will be up to a 5-minute delay before the compressor turns on.
CAUTION
To prevent compressor and/or property damage, if the outdoor temperature is
below 50°F, DO NOT operate the cooling system.
Do not allow the compressor to run unless the compressor oil heaters have been
operational for 6 hours and the system has not been operational for at least 5
minutes.
USING THE THERMOSTAT
THERMOSTAT OVERVIEW
Before you begin using your thermostat, you should be familiar with its features, display and the location/operation of the thermostat buttons and switches.
| THERMOSTAT BUTTONS AND SWITCHES | THE DISPLAY |
|---|---|
| 1.) Fan Switch | 5.) The thermostat protects the equipment from short cycling |
(5-minute delay)
2.) System Switch| 6.) Indicates that the system is running in cool, heat or
auxiliary mode (The auxiliary will run in Heat mode when the heat pump cannot
maintain the set temperature.)
3.) Raises Temperature Setting| 7.) Temperature setpoint
4.) Lowers Temperature Setting| 8.) Displays when the thermostat setpoint has
reached the maximum or minimum setting.
| 9.) Room Temperature
| 10.) SEE TROUBLESHOOTING
TROUBLESHOOTING
| Symptom | Possible Cause | Corrective Action |
|---|
No Heat/ No Cool/ No Fan
(common problem)
| 1.) Blown fuse or tripped circuit breaker
2.) Furnace power switch to OFF
3.) The furnace blower compartment door panel is loose or not properly installed
4.) Loose connection to thermostat or system
| 1.) Replace fuse or reset breaker
2.) Turn the switch to ON
3.) Replace the door panel in the proper position to engage the safety interlock or door switch
4.) Tighten Connections
No Heat /
No First Stage Heat
|
1.) System Switch not set to Heat
2.) Loose connection to thermostat or system
3.) The Heating System requires service or the thermostat requires replacement
4.) Misconfiguration between menu item 20 and a jumper wire
5.) O/B Switch set incorrectly
| Verify thermostat and system wires are securely attached.
Diagnostic: Set the System Switch to Heat and raise the setpoint above room temperature. Within five minutes the thermostat should make a soft click sound and “Heat On” should appear on display. This sound indicates the thermostat is operating properly. If the thermostat does not click, try
the reset operation listed after this charting.
If the thermostat does not click after being reset, contact your heating and cooling service person or place of purchase for a replacement. If the thermostat clicks, contact the furnace manufacturer or a service person to verify the heating system is operating correctly. Make sure that menu item 20 and the jumper wire match.
No Cool
|
1.) System Switch not set to Cool
2.) Loose connection to thermostat or system
3.) The Cooling System requires service or the thermostat requires replacement
4.) O/B Switch set incorrectly
| Verify thermostat and system wires are securely attached.
Diagnostic: Set the System Switch to Cool and lower the setpoint below room temperature. The same
procedures as diagnostic for “No Heat” condition except set the thermostat to Cool and lower the setpoint below the room temperature. There may be up to a five-minute delay before the thermostat clicks in Cooling if the compressor lock-out option is selected in the installer menu. (see INSTALLER MENU, item 50)
Heat, Cool or Fan Runs Constantly
|
Possible short in wiring, thermostat, heat, cool or fan system
|
Check each wire connection to verify they are not shorted or touching other wires. Try resetting the thermostat. If the condition persists contact your HVAC service person.
Thermostat Display & Thermometer Disagree
|
The thermostat display requires adjustment
|
The display can be adjusted +/-5°. See User Menu item 04
| Symptom | Possible Cause | Corrective Action |
|---|
Furnace (Air Conditioner) Cycles Too Fast or Slow (narrow or wide temperature swing) /
No First Stage Heat
| ****
The location of the thermostat and/or the size of the Heating System may be influencing the cycle rate
| Digital thermostats provide precise control and cycle faster than older mechanical models. The system turns on and off more frequently, but runs for a shorter time. If you would like to increase cycle time, choose SLO for slow cycle in the Installer menu. (Reference menu items 30 & 35) If an acceptable cycle rate is not achieved, contact your HVAC service person.
The “Call for Service” icon appears on the display
| 1.) The heating system is not able to heat the space to within 10 degrees of the setpoint within 2 hours
2.) The cooling system is not able to cool the space to within 10 degrees of the setpoint within 2 hours
3.) If “–” is displayed for the Room Temperature, a replacement thermostat is needed
4.) None of the buttons operate on the thermostat
5.) If “Call for Service” is flashing, the compressor self-diagnostic is detecting an issue with the
outdoor unit
| 1.) See corrective action for “No Heat” 2.) See corrective action for “No Cool” 3.) Replace thermostat
4.) Check for a stuck button
5.) Contact a service person to verify the equipment is operating correctly
Resetting the Thermostat or Thermostat Settings
To conveniently reset only the user settings back to factory defaults, press
the temperature and buttons move the system switch from OFF to HEAT at the
same time and hold until the display goes blank and resets.
FCC STATEMENT
WARNING: This product contains a chemical known to the state of California to cause cancer birth defects and other reproductive harm.
NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, according to part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used under the instructions, may cause harmful interference to radio communications. However, there is no gurantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
- Reorient or relocate the receiving antenna
- Increase the separation between the equipment and the receiver
- Connect the equipment to an outlet on a circuit different from that to which the receiver is connected
- Consult the dealer or an experienced radio/TV technician for help
CONTACT
- MERCURY NOTICE: This product does not contain mercury. However, this product may replace a product that contains mercury. Mercury and products containing mercury must not be discarded in household trash.
- Refer to www.thermostat-recycle.org for information on disposing of products containing mercury
- emerson.com/white-rodgers.
- 1-888-725-9797
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>