ICP PGN324 Installation instructions manual - Caution
19
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
UNIT OPERATION HAZARD
Failure to follow this caution may result in unit damage.
For cooling operation, the recommended airflow is 350
to 450 cfm for each 12,000 Btuh of rated cooling
capacity. For heating operation, the airflow must
produce a temperature rise that falls within the range
stamped on the unit rating plate.
CAUTION
!
Table 8 shows the temperature rise in each heating mode.
Refer to these tables to determine the desired heating
airflow for the system being installed. (See Table 9 for wet
coil pressure drop).
NOTE: Be sure that all supply--and return--air grilles are
open, free from obstructions, and adjusted properly. Airflow
can be changed using the User Interface.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect electrical power to the unit and install lockout
tag before changing blower speed.
!
WARNING
Airflow can be changed by changing the lead connections
of the blower motor.
All PGN3 units are factory wired for low speed, except the
030 through 048 sizes, which are wired for medium speed.
FOR 208/230V
For color coding on the 208/230V motor leads, see Table 6.
Table 5—
Color Coding for 208/230V Motor Leads
BLACK = HIGH SPEED
Blue = Medium Speed
Red = Low Speed
To change the speed of the indoor fan motor (IFM), remove
the fan motor speed leg lead from the blower relay (BR).
This wire is attached to terminal blower motor (BM) of the
integrated gas control (IGC) board for single--phase units.
To change the speed, remove and replace with lead for
desired blower motor speed. Insulate the removed lead to
avoid contact with chassis parts.
COOLING SEQUENCE OF OPERATION
With the room thermostat SYSTEM switch in the COOL
position and the FAN switch in the AUTO position, the
cooling sequence of operation is as follows:
1. When the room temperature rises to a point that is
slightly above the cooling control setting of the
thermostat, the thermostat completes the circuit
between thermostat terminal R to terminals Y and G.
2. The normally open contacts of energized contactor (C)
close and complete the circuit through compressor
motor (COMP) to condenser (outdoor) fan motor
(OFM). Both motors start instantly.
3. The set of normally open contacts of energized relay
BM close and complete the circuit through evaporator
blower (indoor) fan motor (IFM).
NOTE: Once the compressor has started and then stopped,
it should not be started again until 5 minutes have elapsed.
The cooling cycle remains on until the room temperature
drops to a point that is slightly below the cooling control
setting of the room thermostat. At this point, the thermostat
breaks the circuit between thermostat terminal R to
terminals Y and G. These open circuits deenergize
contactor coil C. The condenser and compressor motors
stop. After a 30--sec. delay, the blower motor stops. The unit
is in a standby condition, waiting for the next call for cooling
from the room thermostat.
MAINTENANCE
To ensure continuing high performance and to minimize the
possibility of premature equipment failure, periodic
maintenance must be performed on this equipment. This
unit should be inspected at least once each year by a
qualified service person. To troubleshoot unit, refer to Table
10, Troubleshooting Chart.
NOTE TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal
injury or death and unit component damage.
The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills,
tools and equipment. If you do not possess these, do not
attempt to perform any maintenance on this equipment,
other than those procedures recommended in the
Owner’s Manual.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow these warnings could result in personal
injury or death:
1. Turn off electrical power to the unit before performing
any maintenance or service on this unit. Install lock-
out tag.
2. Use extreme caution when removing panels and
parts.
3. Never place anything combustible either on or in
contact with the unit.
!
WARNING
UNIT OPERATION HAZARD
Failure to follow this caution may result in improper
operation.
Errors made when reconnecting wires may cause
improper and dangerous operation. Label all wires prior
to disconnecting when servicing.
CAUTION
!