Form O-Y P/N 273647R5, Page 27
CAUTION: After cleanup is complete, remove the suction line filter
drier. See Hazard Levels, page 2.
d)
Verify subcooling and superheat (refer to
Step 11
).
e) When the system is operating properly, remove the gauges.
Or, IF
the oil measured in
Step 2
was not significantly less than that
shown in the table on page 20 or the acid test in
Step 2
did not indi-
cate a compressor burnout, continue to the review in
Step 13
.
•
Step 13
. Review
ALL Steps
to ensure that nothing was overlooked.
All systems have a unit-mounted, 24-volt programmable controller. The controller
is factory programmed to match the control selection on the order (Option D19 for
space temperature control or Option D21 for makeup air control). See the appropriate
control instruction manual, Form CP-Y D19 or CP-Y D21, for more details.
Some sensors are standard and others will depend on option selection.
Service:
If a sensor needs to be replaced, use only a factory authorized replacement
part designed for the purpose.
If a controller needs to be replaced, it must be replaced with the same controller and
software. Contact your distributor or the factory service department for details.
3.8 Other Controls
3.8.1 Programmable Digital Controller and Sensors
System
Programmable
Controller with
Integral Display
3.8.2 Voltage
Protection,
Option PL4
Function:
Phase loss and low or high voltage can cause damage to electrical com-
ponents. This safety control monitors phase loss and voltage and shuts down the unit
when its limits are exceeded. The device is auto reset and allows the unit to restart
when the power conditions are corrected.
4.1 Power Exhaust, Option PE
If equipped with optional power exhaust, there is an ECM fan in the exhaust airstream
and gravity dampers in the opening on the corner of the "access" side of the system.
The power exhaust fan operation is from a constant volume, in response to a building
pressure sensor, or by an adjustable offset to the supply fan. Adjustments and set-
tings are through the system controller.
Service:
Power exhaust fan motor is permanently lubricated; lubrication is not
required, During maintenance, remove any accumulation of dirt and grease from the
fan and dampers. The exhaust fan CFM was checked and balanced at startup. To
recheck, follow the instructions in the installation manual, Form I-Y, Paragraph 10.3.
The system may be equipped with either an integral power exhaust or an energy
recovery wheel with an attached power exhaust module.
Optional Power
Exhaust Damper
is in the door
allowing access
to the power
exhaust fan.
FIGURE 19 - Exhaust
Damper Location
for either gravity or
power exhaust
4.0 Maintenance/Service Procedures - Power Exhaust and Energy Recovery
