FORM 150.66-NM3
ISSUE DATE: 09/25/2020
39
JOHNSON CONTROLS
55
Commissioning of this unit should
only be carried out by Johnson Con-
trols 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 on page 41 as the commissioning proce-
dure 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 YORK hand oil pump
(Part No. 470-10654-000) to the 1/4 in. oil charging
valve on the oil separator piping with a length of clean
hose or copper line, but do not tighten the are nut. Us-
ing clean oil of the correct type (F 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.
The oil level should be visible in the bottom half of the
sight glass at shutdown and while running at full load.
Approximately 4 gal to 5 gall is present in the each
refrigerant system, with typically 1 gal to 2 gal in each
oil separator. Oil levels above the top sight glass should
be avoided and may cause excessive oil carryover in
the system. High oil concentration in the system may
cause nuisance trips resulting from incorrect readings
on the level sensor and temperature sensors. Tempera-
ture sensor errors may result in poor liquid control and
resultant liquid overfeed and subsequent damage to the
compressor.
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 xed.
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 SECTION
6 - TECHNICAL DATA has not been exceeded.
Control Panel
Check the panel to see that it is free of foreign materi-
als (wire, metal chips, or other material) 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.
Grounding
Verify that the unit’s protective ground terminal(s) are
properly connected to a suitable grounding point. En-
sure that all unit internal ground connections are tight.
SECTION 5 - COMMISSIONING
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