18-GL07D1-4
29
2GN SPLIT INSTALLER’S GUIDE
UNIT STARTUP
Before Powering Unit,
Check The Following:
• High voltage is correct and matches nameplate.
• Fuses, breakers and wire size correct.
• Low voltage wiring complete.
• Piping completed and water system cleaned and
fl ushed.
• Air is purged from closed loop system.
• Isolation valves are open, water control valves or
loop pumps wired.
• Condensate line open and correctly pitched.
• Transformer switched to 208V if applicable.
• DIP switches are set correctly.
• DHW pump switch is “OFF” unless piping is
completed and air has been purged.
• Blower rotates freely.
• Blower speed correct.
• Air fi lter/cleaner is clean and in position.
• Service/access panels are in place.
• Return air temperature is between 50-80ºF heating
and 60-95ºF cooling.
• Check air coil cleanliness to ensure optimum
performance. Clean as needed according to
maintenance guidelines. To obtain maximum
performance the air coil should be cleaned before
startup. A 10-percent solution of dishwasher
detergent and water is recommended for both sides
of coil, a thorough water rinse should follow.
Startup Steps
Notes:
Complete the Equipment Start-Up/Commissioning
Check Sheet during this procedure. Refer to thermostat
operating instructions and complete the startup procedure.
1. Initiate a control signal to energize the blower motor.
Check blower operation.
2. Initiate a control signal to place the unit in the cooling
mode. Cooling setpoint must be set below room
temperature.
3. First stage cooling will energize after a time delay.
4. Be sure that the compressor and water control valve or
loop pump(s) are activated.
5. Verify that the water fl ow rate is correct by measuring
the pressure drop through the heat exchanger using
the P/T plugs and comparing to unit capacity data in
specifi cation catalog.
6. Check the temperature of both the supply and
discharge water (see Operating Parameters tables).
7. Check for an air temperature drop of 15°F to 25°F
across the air coil, depending on the fan speed and
entering water temperature.
8. Decrease the cooling set point several degrees and
verify high-speed blower operation.
9.
Adjust the cooling setpoint above the room temperature
and verify that the compressor and water valve or loop
pumps deactivate.
10. Initiate a control signal to place the unit in the heating
mode. Heating set point must be set above room
temperature.
11. First stage heating will energize after a time delay.
12. Check the temperature of both the supply and
discharge water (see Operating Parameters tables).
13. Check for an air temperature rise of 20°F to 35°F
across the air coil, depending on the fan speed and
entering water temperature.
14. If auxiliary electric heaters are installed, increase
the heating setpoint until the electric heat banks
are sequenced on. All stages of the auxiliary heater
should be sequenced on when the thermostat is in
the Emergency Heat mode. Check amperage of each
element.
15. Adjust the heating setpoint below room temperature
and verify that the compressor and water valve or loop
pumps deactivate.
16. During all testing, check for excessive vibration, noise
or water leaks. Correct or repair as required.
17. Set system to desired normal operating mode and set
temperature to maintain desired comfort level.
18. Instruct the owner/operator in the proper operation of
the thermostat and system maintenance.
Notes:
Be certain to fi ll out and forward all warranty registration
papers.
Final Evaluation
After the initial check of superheat/subcooling values in the
heating mode, shut off the unit and allow it to sit 3 to 5 minutes
until pressures equalize. Restart the unit in the cooling
mode and check the values against those in the Operating
Parameters tables If the unit performs satisfactorily, charging
is complete. If the unit does not perform to specifi cations,
the charge may need to be readjusted until the values are
close. Adding refrigerant will increase subcooling. Recovering
some of the refrigerant will decrease subcooling and increase
superheat. If the superheat/subcooling values are still not
close to the specifi cations in the Operating Parameters tables,
analyze refrigerant circuit operation.
Summary of Contents for 2GN Series
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