RTHD-SVX02H-EN 101
Periodic Maintenance
Overview
This section describes preventative maintenance proce-
dures and intervals for the Series R unit. Use a periodic
maintenance program to ensure optimal performance
and efficiency of the Series R units.
An important aspect of the chiller maintenance program
is the regular completion of the “Series R Operating
Log”; an example of this log is provided in this manual.
When filled out properly the completed logs can be re-
viewed to identify any developing trends in the chiller’s
operating conditions.
For example, if the machine operator notices a gradual
increase in condensing pressure during a month’s time,
he can systematically check for and then correct, the pos-
sible cause(s) of this condition (e.g., fouled condenser
tubes, non-condensables in the system).
Weekly Maintenance and Checks
After the unit has operated for approximately 30 minutes
and the system has stabilized, check the operating condi-
tions and complete the procedures below:
• Log the chiller.
• Check evaporator and condenser pressures with
gauges and compare to the reading on the Clear Lan-
guage Display. Pressure readings should fall within
the following ranges specified in the Operating Con-
ditions.
Note: Optimum condenser pressure is dependent on
condenser water temperature, and should equal
the saturation pressure of the refrigerant at a tem-
perature 2 to 5°F above that of leaving condenser
water at full load.
Monthly Maintenance and Checks
• Review operating log.
• Clean all water strainers in both the chilled and con-
densing water piping systems.
• Measure the oil filter pressure drop. Replace oil filter
if required. Refer to “Service Procedures”.
• Measure and log the subcooling and superheat.
• If operating conditions indicate a refrigerant short-
age, leak check the unitan confirm using soap bub-
bles.
• Repair all leaks.
• Trim refrigerant charge until the unit operates in the
conditions listed in the note below.
Note: ARI conditions are: condenser water: 85°F and 3
GPM per ton and evaporator water: 54-44°F.
Table 31. Operating Conditions at Full Load
Description Condition
Evaporator pressure 40-55 psig
Condensing pressure 85-120 psig
Discharge superheat 17
°
F
Subcooling 5-10
°
F
EXV percent open 40-50% open in Auto mode
All conditions stated above are based on the unit running fully load-
ed, running at ARI conditions.
• If full load conditions can not be met. Refer to note
below to trim the refrigerant charge.
Note: Conditions at minimum must be: entering con-
denser water: 85°F and entering evaporator water:
55°F.
Table 32. Operating Conditions at Minimum Load
Description Condition
Evaporator approach *less than 7
°
F (non-glycol
applications)
Condensing approach *less than 7
°
F
Subcooling 2-3
°
F
EXV percent open 10-20 % open
*≈1.0
°
F for new unit.
Annual Maintenance
Shut down the chiller once each year to check the follow-
ing:
D
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote discon-
nects before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadver-
tently energized. Failure to disconnect power before
servicing could result in death or serious injury.
• Perform all weekly and monthly maintenance proce-
dures.
• Check the refrigerant charge and oil level. Refer to
“Maintenance Procedures”. Routine oil changing is
not necessary on a hermetic system.
• Have a qualified laboratory perform an oil analysis to
determine system moisture content and acid level.
Note: IMPORTANT: Due to the hygroscopic properties
of the POE oil, all oil must be stored in metal
containers. The oil will absorb water if stored in a
plastic container
• Check the pressure drop across the oil filter. Refer to
“Maintenance Procedures”.
• Contact a qualified service organization to leak check
the chiller, to inspect safety controls, and inspect
electrical components for deficiencies.
• Inspect all piping components for leakage and/or
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