Dunham-Bush ACDX, Installation, Operation And Maintenance Instructions

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7. The electrical control settings should be checked and, if To prevent moisture entering the system and
necessary, reset to those settings indicated on the wiring contaminating the oil extra care is necessary. Follow
diagram. Safety controls are factory set and must be the enclosed procedure to add or remove oil from the
maintained at settings indicated on the wiring diagram. system.
8. The temperatures of the chilled water both in and out, The holding tank must be clean and free of any
should be checked to insure the unit is operating within moisture. (Evacuate tank to 200 microns). The holding
the desired temperatures. tank can be a receiver or reclaiming tank of a size large
MAINTENANCE withstand the operating pressure of the system. When
CONDENSER supplied to a holding tank and then evacuated through
Units are equipped with direct drive fans that have inherently the vapor port down to 200 microns. Do not allow the
protected motors with permanently lubricated bearings. container to vent to the atmosphere as the transfer must
The air inlet of the condenser coil should be kept clean required.
through a regular maintenance program.
COMPRESSOR
1. OIL LEVEL - The oil level in the compressor(s) should be
checked periodically, with the compressor stopped.
Stage the unit down until all compressors are off and
check the compressor crankcase sight glass for oil level.
If the oil level is below one half (1/2) the sight glass, oil
must be added.
2. A. RECOMMENDED OIL FOR R-22 MACHINES
Compressor Model Series SSCA - The compressor
is factory charged with DB Karlube #10 Oil.
Compressor Model Series SSCB - The compressor
is factory charged with DB Karlube #21 Oil.
Do not mix above oils or attempt to operate the
screw compressor with any other oil. It is
suggested that a gallon or more of the appropriate
oil be obtained and kept at the job site.
DB Karlube #10
DB Karlube #21
B. RECOMMENDED OIL FOR R407C MACHINES
DO NOT USE DB Karlube #10.
Compressor Models SSCA use DB Karlube #16
Oil.
Compressor Models SSCB use DB Karlube #21
Oil.
Contact factory for price.
The above-listed oils are synthetic lubricants of the
Polyol Ester (POE) type. Due to the complex
nature of the POE, great precaution must be taken
to prevent any moisture from entering the system
when servicing or adding oil. POE oil has a
greater solvency for water. Water reacts
chemically with the ester to form acids and
alcohols in a process called "hydrolysis". POE
molecules attract moisture. Moisture removal by
evacuation is more difficult because the POE
"holds water more tightly" than mineral oil.
Moisture causes corrosion and copper plating at an
unacceptable, high level. This reaction occurs
where temperatures are the highest within the
compressor.
enough for the total oil change and must be able to
adding oil, it should be transferred from the container
be done through a closed loop. An oil pump will be
PROCEDURE FOR ADDING OIL
Manually close liquid line service valve. Lower return
water T-stat (4TAS) setting to start the compressor. Run
compressor until unit shuts down on low pressure. Place
the control circuit on/off switch in the off position. Locate
the high pressure port adjacent to solenoid valve UL-3
(see drawing page 8) and remove the cap. Attach oil
pump to holding tank high pressure port. Pump oil into
this port until the oil level is 1/2 of the sight glass.
Replace the port cap, open the liquid line shut off valve
and place the control circuit on/off switch in the on
position. Set the operating T-stat to the normal operating
temperature and reset the low pressure switch.
Oil can also be added, through the suction port of the
compressor, while running the compressor.
3. COMPRESSOR REPAIRS (Internal) - Contact factory or
an authorized DB Service Agency if a compressor
malfunction is suspected.
4. COMPRESSOR REPAIRS (External) - Proper operation
of unloaded start, loading, and unloading is controlled by
solenoid valves UL-1, UL-2 and UL-3. Any of these three
(3) solenoid valves may be repaired or replaced in the
field, as required. Also the compressor crankcase heater
may be replaced.
5. Standard oil acid test kit is not compatible with synthetic
oil. See DB color chart for oil condition.
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