York YLUA0248 Series, Установка, эксплуатация и обслуживание

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JOHNSON CONTROLS
89
FORM 150.73-NM2
ISSUE DATE: 09/07/2020
6
COMMISSIONING
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.
Perform the commissioning using the detailed checks
outlined in the
Installation and Start-up Checklist
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
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
repaired. Condensing units are supplied with a nitro-
gen or refrigerant holding charge (Refer to tag on unit).
These systems must be evacuated with a suitable vac-
uum pump/recovery unit as appropriate to below 500
microns.
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 18° F subcooling.
Service and Oil Line Valves
Open each compressor suction, and discharge 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” oil charging
valve on the compressors with a length of clean hose
or copper line, but do not tighten the flare nut. Using
clean oil of the correct type (“V” 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 between the bottom and middle
of the sight glass. Check oil levels after operating the
system at full load. 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 re-
sultant 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
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.
Supply Voltage
Verify that the site voltage supply corresponds to the
unit requirement and is within the limits given in
SEC-
TION 5 – TECHNICAL DATA
.
SECTION 6 – COMMISSIONING