Carrier 48VL-E Installation Instructions Manual page 31

48VL-(E, F): Installation Instructions
A
MAX DISTANCE BETWEEN TOP OF FAN GRILLE AND BOTTOM OF FAN BLADE
Size
24
30
36
42
48
60
Electrical Controls and Wiring
Inspect and check the electrical controls and wiring annually. Be sure to
turn off the electrical power to the unit.
Remove access panels (see Fig.
and wiring. Check all electrical connections for tightness. Tighten all
screw connections. If any smoky or burned connections are noticed,
disassemble the connection, clean all the parts, re-strip the wire end and
reassemble the connection properly and securely.
After inspecting the electrical controls and wiring, replace all the panels.
Start the unit, and observe at least one complete cooling cycle to ensure
proper operation. If discrepancies are observed in operating cycle, or if a
suspected malfunction has occurred, check each electrical component
with the proper electrical instrumentation. Refer to the unit wiring label
when making these checks.
Refrigerant Circuit
Annually inspect all refrigerant tubing connections.
EXPLOSION, SAFETY AND ENVIRONMENTAL HAZARD
Failure to follow this warning could result in personal injury, death or
property damage.
System under pressure. Relieve pressure and recover all refrigerant
before system repair or final unit disposal. Use all service ports and open
all flow-control devices, including solenoid valves.
If low cooling performance is suspected, leak-test all refrigerant tubing
using an electronic leak-detector or liquid-soap solution. If a refrigerant
leak is detected, refer to the Check for Refrigerant Leaks section.
If no refrigerant leaks are found and low cooling performance is
suspected, refer to the Checking and Adjusting Refrigerant Charge
section.
Gas Input
The gas input does not require checking unless improper heating
performance is suspected. If a problem exists, refer to the Start-Up
section.
Evaporator Airflow
The heating and/or cooling airflow does not require checking unless
improper performance is suspected. If a problem exists, be sure that all
supply- and return-air grilles are open and free from obstructions, and
that the air filter is clean. When necessary, refer to the Indoor Airflow
and Airflow Adjustments section to check the system airflow.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
MOTOR
Fig. 23 – Fan Blade Position
21) to locate all the electrical controls
FAN GRILLE
MOTOR SHAFT
"A"
in.
9.0
7.1
8.0
7.6
7.6
7.6
Puron (R-410A) Items
The indoor metering device is either a TXV or orifice type device
depending on size.
Pressure Switches
Pressure switches are protective devices wired into control circuit (low
voltage). They shut off compressor if abnormally high or low pressures
are present in the refrigeration circuit. These pressure switches are
specifically designed to operate with Puron (R-410A) systems. R-22
pressure switches must not be used as replacements for the Puron
(R-410A) system.
Low Pressure Switch (24 size only)
This switch is located on the suction line and protects against low
suction pressures caused by such events as loss of charge, low airflow
across indoor coil, dirty filters, etc. It opens at 50 psig. If system
pressure is above this, switch should be closed. To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have continuity
on a closed switch.
NOTE: Because these switches are attached to refrigeration system
under pressure, it is not advisable to remove this device for
troubleshooting unless you are reasonably certain that a problem exists.
If switch must be removed, remove and recover all system charge so that
pressure gauges read 0 psig. Never open system without breaking
vacuum with dry nitrogen.
High-Pressure Switch
The high-pressure switch is located in the discharge line and protects
against excessive condenser coil pressure. It opens at 650 psig.
High pressure may be caused by a dirty outdoor coil, failed fan motor, or
outdoor air recirculation. To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have continuity
on a closed switch.
31
A08505
mm
228
180
203
193
193
193