Service; Maintenance Schedule; Suction And Discharge Service Valves - Carrier 68G5-105 Series Operation & Service Manual

BE SURE TO OBSERVE WARNINGS LISTED IN THE SAFETY SUMMARY IN THE FRONT OF THIS
MANUAL BEFORE PERFORMING MAINTENANCE ON THE HVAC SYSTEM
Following completion of all maintenance or service activities, the alarm queue should be cleared of any
original alarms and any alarms generated during service. Refer to paragraph 2.1.6

4.1 MAINTENANCE SCHEDULE

SYSTEM
ON OFF
a. Daily Maintenance
X Pre-trip Inspection -- after starting
X Check tension and condition of V-belt
b. Weekly Inspection
X Perform daily inspection
X Check condenser, evaporator coils and air filters for cleanliness
X Check refrigerant hoses and compressor shaft seal for leaks
X Feel filter-drier for excessive temperature drop across drier
c. Monthly Inspection and Maintenance
X Perform weekly inspection and maintenance
X Clean evaporator drain pans and hoses
X Check wire harnesses for chafing and loose terminals
X Check fan motor bearings
X Check compressor mounting bolts for tightness
X Check fan motor brushes
4.2 SUCTION AND DISCHARGE SERVICE
VALVES
The suction and discharge service valves (See
Figure 4-1) 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.
SECTION 4

SERVICE

WARNING
NOTE
OPERATION OPERATION
TO DISCHARGE OR
FROM SUCTION LINE
PORT TO
COMPRESSOR
ACCESS VALVE CAP
Service Valve
Frontseated
(clockwise)
Figure 4-1. Suction or Discharge Service Valve
4-1
REFERENCE REFERENCE
paragraph
2.2
None
4.1.a
None
4.5
4.10
4.1.b
None
Replace/Tighten
None
None
4.19, 4.23
VALVE STEM CAP
VALVE
STEM
ACCESS VALVE
(R-134a)
Service Valve
Backseated
(counterclockwise)
T-312