Specifications

45
JOHNSON CONTROLS
Form 201.28-NM1.EN.PED/CE (0211)
6
SECTION 6 - COMMISSIONING
PREPARATION
Commissioning of this unit should only be
carried out by Johnson Controls Authorized
personnel.
Commissioning personnel should be thoroughly familiar
with the information contained in this document before
starting the unit.
Commission the unit using the detailed
checks outlined in the Equipment Pre -
Startup Checklist and Startup Checklist
found at the end of this section.
The following basic checks should be made with the
customer power to the unit switched OFF.
Proper electrical lock out and tag out
procedures must be followed.
Inspection
Inspect unit for installation damage. If found, take action
and/or repair as appropriate.
Refrigerant Charge
Packaged units are normally shipped as standard with a
full refrigerant operating charge. Check that refrigerant
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.
Do not evacuate or liquid charge with static water in the
cooler. Turn the pump on. Take care to liquid charge
slowly to avoid excessive thermal stress at the charging
point and to assure the refrigerant temperature in the
evaporator does not go below the freezing point with
liquid refrigerant in the evaporator. Once the vacuum is
broken, charge into the evaporator or flash tank with the
Condenser Drain Valve (Flash Tank Feed) open and the
chilled liquid pump ON to the full operating charge, as
detailed in Section 5 Technical Data.
Correct System Refrigerant Charge
The charge on a system should always be checked when
operating for several minutes at full speed with the system
stable. Stable conditions are defined as operation without
fan cycling, economizer cycling, VI solenoid cycling, or
any other system transient conditions. Ideal refrigerant
charge will be reached when the refrigerant level in the
evaporator is near the middle of the evaporator sight
glass.
Refrigerant should not be added or removed
unless the level is at the bottom or the top
of the glass. It is not necessary to weigh
charge unless the entire charge has been
lost. The ease of charging is possible since
the microchannel coils hold only a small
amount of refrigerant charge. A charging
valve is located between the fi xed orifi ce
and the evaporator for adjusting charge.
Charge should be added as liquid with the
pump ON and liquid fl owing through the
evaporator.
Service and Oil Line Valves
Open each compressor oil, economizer, and discharge
ball or service valves. 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.
Compressor Oil
To add oil to a circuit - connect a YORK hand oil pump
(Part No. 470-10654-000) to the 1/4" (6.35 mm) oil
charging valve on the oil separator piping with a length
of clean hose or copper line, but do not tighten the flare
nut. Using clean oil of the correct type (“L” 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.
While the compressor is running at full speed, the oil
level should be visible at the bottom of the lower and
middle of the upper sight glasses of the oil separator.