Unit Startup - York YAST026 Installation Manual

Unit Startup

Before Powering Unit, Check the Following:
NOTE: Remove and discard the compressor hold down shipping
bolt located at the front of the compressor mounting bracket.
• High voltage is correct and matches nameplate.
• Fuses, breakers and wire size correct.
• Low voltage wiring complete.
• Piping completed and water system cleaned and flushed.
• 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.
• Blower rotates freely.
• Blower speed is correct.
• Air filter/cleaner is clean and in position.
• Service/access panels are in place.
• Return air temperature is between 50-80°F heating and
60-95°F 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% solution of dishwasher detergent and
water is recommended for both sides of coil, a thorough water
rinse should follow.
Startup Steps
NOTE: Complete the Equipment Start-Up/Commissioning Check
Sheet during this procedure. Refer to thermostat operating
instructions and complete the startup procedure. Verify that the
compressor shipping bolt has been removed.
1. Initiate a control signal to energize the blower motor.
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 flow rate is correct by measuring the
pressure drop through the heat exchanger using the P/T plugs
and comparing to unit performance data in catalog.
6. Check the temperature of both the supply and discharge water
(see the Unit 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.
AFFINITY DUAL-CAPACITY OUTDOOR SPLIT SERIES INSTALLATION MANUAL
11. First stage heating will energize after a time delay.
12. Check the temperature of both the supply and discharge water
(see the Unit Operating Parameters tables).
13. Check for an air temperature rise of 12°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.
NOTE: Be certain to fill out and forward all warranty
registration papers.
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