4-1
SECTION 4
SERVICE
WARNING
BEWARE OF ROTATING FAN BLADES AND
UNANNOUNCED STARTING OF FANS.
4.1 MAINTENANCE SCHEDULE
UNIT
OPERATION
REFERENCE
ON
OFF
OPERATION
REFERENCE
SECTION
a. Daily Maintenance
X
X
Pre-trip inspection --- after starting
Check tension and condition of Compressor V-belt(s)
2.2
None
b. Weekly Inspection and Maintenance
X
X
X
X
Perform daily inspection
Check condenser, evaporator coils and air filters
Check refrigerant hoses and compressor shaft seal for leaks
Feel filter-drier for excessive temperature drop across drier.
4.1.a
None
4.6
4.10
c. Monthly Inspection and Maintenance
X
X
X
X
X
Perform weekly inspection and maintenance
Clean evaporator drain pan and hose(s)
Check wire harness for chafing and loose terminals
Check fan motor bearings
Check compressor mounting bolts for tightness
4.1.b
None
Repair/Tighten
None
Check/Tighten
4.2 SUCTION AND DISCHARGE SERVICE
VALVES
The suction and discharge service valves used on the
compressor are equipped with mating flanges for
connection to flanges on the compressor. These valves
are provided with a double seat and a gauge connection,
which allows servicing of the compressor and refrigerant
lines.
Turning the valve stem counterclockwise (all the way
out) will backseat the valve to open the suction or
discharge line to the compressor and close off the gauge
connection. In normal operation, the valve is backseated
to allow full flow through the valve. The valve should
always be backseated when connecting the service
manifold gauge lines to the gauge ports.
Turning the valve stem clockwise (all the way forward)
will frontseat the valve to close off the suction or discharge
line to isolate the compressor and open the gauge
connection.
To measure suction or discharge pressure, midseat
the valve by opening the valve clockwise 1/4 to 1/2 turn.
With the valve stem midway between frontseated and
backseated positions, the suction or discharge line is
open to both the compressor and the gauge connection.
Gauge
Connection
Valve Cap
Valve
Stem
To Discharge or
from Suction Line
Port to
Compressor
Service Valve
Frontseated
(clockwise)
Service Valve
Backseated
(counterclockwise)
Figure 4-1. Suction or Discharge Service Valve
4.3 MANIFOLD GAUGE SET
The manifold gauge set can be used to monitor system
operation pressure, add or remove refrigerant, evacuate,
and equalize the system.
The manifold gauge in Figure 4-2 shows hand valves,
gauges and refrigerant openings. When the manifold
hand valves are backseated (open), the high and low side