Quantech QWC3050T-200T, Installation Operation & Maintenance

Page: 105 / 186

FORM QWC3-NM1
ISSUE DATE:11/20/2020
QUANTECH
105
6
Commissioning of this unit should only
be carried out by Quantech authorized
personnel.
Commissioning personnel should be thoroughly famil-
iar with the information contained in this literature, in
addition to this section.
Perform the commissioning using the detailed checks
outlined in the “Equipment Pre-startup and Startup
Checklist” (located in this section of the IOM) as the
commissioning procedure is carried out.
PREPARATION – POWER OFF
The following basic checks should be made with the
customer power to the Unit Switched OFF.
Inspection
Inspect unit for installation damage. If found, take ac-
tion and/or repair as appropriate.
Refrigerant Charge
Packaged units are normally shipped as standard with
a full refrigerant operating charge. Check that refrig-
erant pressure is present in both systems and that no
leaks are apparent. If no pressure is present, a leak test
must be undertaken, the leak(s) located and repaired.
Remote systems and units are supplied with a nitrogen
holding charge. These systems must be evacuated with
a suitable vacuum pump/recovery unit as appropriate
to below 500 microns.
Do not liquid charge with static water in the cooler.
Care must also be taken to liquid charge slowly to
avoid excessive thermal stress at the charging point.
Once the vacuum is broken, charge into the condens-
er coils with the full operating charge as given in the
Technical Data Section.
Service and Oil Line Valves
Open each compressor suction, economizer, and dis-
charge service valve. If valves are of the back-seat
type, open them fully (counterclockwise) then close
one turn of the stem to ensure operating pressure is fed
to pressure transducers. Open the liquid line service
valve and oil return line ball valve fully in each system.
Compressor Oil
To add oil to a circuit – connect a hand oil pump (Part
No. 470-10654-000) to the 1/4” oil charging connec-
tion on the compressors with a length of clean hose or
copper line. Do not tighten the flare nut. Using clean
oil of the correct type (Models QWC3050 to 0150 use
POE synthetic “V” oil, Models QWC3170 to 200 use
“PVE” oil.), pump oil until all air has been purged from
the hose then tighten the nut. Stroke the oil pump to
add oil to the oil system. Approximately 1.8 to 2.3 gal-
lons are present in the each refrigerant system. Oil lev-
els in the oil equalizing line sight glass should be be-
tween the bottom and the middle of the sight glass with
the system OFF. High oil levels may cause excessive
oil carryover in the system. High oil concentration in
the system may cause nuisance trips resulting from in-
correct readings on the level sensor and temperature
sensors. Temperature sensor errors may result in poor
liquid control and resultant liquid overfeed and sub-
sequent damage to the compressor. While running, a
visible sign of oil splashing in the sight glass is normal.
Fans
Check that all fans are free to rotate and are not dam-
aged. Ensure blades are at the same height when ro-
tated. Ensure fan guards are securely fixed.
Isolation / Protection
Verify all sources of electrical supply to the unit are
taken from a single point of isolation. Check that the
maximum recommended fuse sizes given in the Tech-
nical Data Section has not been exceeded.
Control Panel
Check the panel to see that it is free of foreign materi-
als (wire, metal chips, etc.) and clean out if required.
Power Connections
Check that the customer power cables are connected
correctly to the terminal blocks or optional circuit
breaker. Ensure that connections of power cables with-
in the panels to the circuit breaker or terminal blocks
are tight.
SECTION 6 – COMMISSIONING