Unit Checks - Power Applied; Initial Start-Up - York YSCD Manual

Startup
UNIT CHECKS – POWER APPLIED
1. Apply 3-phase power to the unit and verify it falls
within the voltage range given in Table 2.
2. Check for voltage imbalance. Voltage imbalance
should not exceed 2% of the average voltage.
3. Use the "Force" function of the Unit Control to
energize the supply fan. Verify that it rotates in
the proper direction.
32

INITIAL START-UP

After all the other preceding checks have been completed
the unit may be placed in operation.
1. Place the "On – Auto – Off" switch in the ON
position.
2. The supply fan will cycle on and permit compressor
operation if the air proving switch for the supply
fan has closed.
3. If there is a demand for cooling, supply air or sup-
ply and return air temperature depending on how
the unit is programmed, the chilled water valve
will modulate open.
4. With an ammeter, verify that each phase of the
supply fan motor is within the RLA/FLA as listed
on the unit data plate.
If the unit is functioning satisfactorily during the
initial operating period, no safety trips and the unit
controls are functioning properly, the unit is ready
to be placed into operation.
FORM 145.05-NOM2 (807)
JOHNSON CONTROLS