York XT AHU - START-UP PROCEDURES; FAN AND DAMPER OPERATION CHECKS

JOHNSON CONTROLS
19
SECTION 2 - START-UP AND OPERATION
FORM 102.20-OM2
ISSUE DATE: 6/01/2015
2
START-UP
Do not be operate this AHU until after
start-up is completed as outlined in these
instructions. Do not allow the AHU to run
on unreliable temporary power, which
could turn the AHU on/off periodically
or rapidly, and to protect it from irregular
voltages and surges.
It is recommended that the start-up technician use the
AHU Start-up Checklist (Form 100.00-CL1), included
with the AHU, and record the gathered information in
the appropriate fields. If there are questions, refer to
Table 11 on page 53 for inspection requirements.
Install the provided or temporary filter media prior to
start-up to adequately protect the components in the air
stream and duct system.
If the AHU is equipped with an energy recovery wheel,
rotate the wheel when the AHU is in service to prevent
clogging.
Checking Operation of Fans
Check of the operation of the fans by:
1. Verifying the correct voltage, phase and cycles.
2. Energizing the power to the AHU disconnect
switch.
3. Energizingthe fan motor(s), briey(bump) and
check for correct fan rotation.
If the fan rotation is incorrect:
1. On three-phase equipment, reverse any two motor
leads at the load side of the last starter component.
2. On single-phase equipment, follow the wiring
diagram on the motor housing or on the inside of
the motor terminal box.
3. Recheck for correct fan rotation.
Checking Operation of Dampers
Most units are shipped with dampers in
closed position. Release and adjustment
is to be done by eld technician only
Make sure the AHU will not operate with all dampers
closed.
Linkage design and/or damper linkage is optional. Air-
flow control dampers may be operated with pneumatic
or electric actuator/controllers.
Prior to occupancy, test the ventilation system to en-
sure that the outdoor air dampers operate properly in
accordance with the system design.
Back Draft Dampers for Dual Fans and Fan
Arrays
The counterbalance is locked into place for shipping
as shown in Figure 6 on page 19. Before startup,
the counterbalance will have to be released. To do this,
loosen the set screws and slide the counterbalance off
the end of the shaft. Flip the counterbalance and slide
it back on the shaft. Rotate the counterbalance above
the damper as shown in Figure 7 on page 19, and
then tighten the set screws. The counterbalance should
be free to rotate.
FIGURE 6 - COUNTERBALANCE LOCKED INTO
PLACE FOR SHIPPING
LD17103
FIGURE 7 - COUNTERBALANCE UNLOCKED FOR
START-UP
LD17198