York YCUL0020, Installation, Operation And Maintenance Manual

Page: 103 / 178

JOHNSON CONTROLS
103
Form 150.63-NM9
Issue date: 5/20/2021
6
Commissioning of this unit should only
be carried out by Johnson Controls Au-
thorized personnel.
Commissioning personnel should be thoroughly famil-
iar with the information contained in this literature, in
addition to this section.
Commissioning should be performed using the de-
tailed checks outlined in the Equipment Pre-Startup
and Startup Checklist on page 105
.
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
Check that 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 re-
paired. Condensing units are supplied with a nitrogen
or refrigerant holding charge (see tag on unit). These
systems must be evacuated with a suitable vacuum
pump/recovery unit as appropriate to below 500 mi-
crons.
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 condenser
coils with the full operating charge to provide 12° F
-15° F subcooling.
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:
1. Connect a YORK hand oil pump (Part No. 470-
10654-000) to the 1/4 in. oil charging valve with
a length of clean hose or copbeforeline, but do not
tighten the flare nut.
2. Using clean oil of the correct type (“V” oil), pump
oil until all air has been purged from the hose,
then tighten the nut.
3. Stroke the oil pump to add oil to the oil system.
The oil level should be between the bottom and
middle of the sight glass.
4. Check oil levels after operating the system at full
load.
5. Turn OFF the system and check the level.
High oil concentration in the system
may cause nuisance trips resulting from
incorrect readings on the level sensor
and temperature sensors. Temperature
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 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 SECTION
5 – TECHNICAL DATA
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 cor-
rectly to the terminal blocks or optional circuit breaker.
Ensure that power cable connections, within the panels
to the circuit breaker or terminal blocks, are tight.
Section 6 – Commissioning