Section 5 Commissioning; Preparation; Preparation - Power Off - York MILLENNIUM YCAS Installation Operation & Maintenance

PREPARATION

Commissioning of this unit should
only be carried out by YORK Autho-
rized personnel.
The Millennium Microcomputer Control System
Operating Instructions must be read in conjunc-
tion with this section.

PREPARATION - POWER OFF

The following checks should be made with the customer
supply/supplies to the unit switched OFF.
Inspection
Inspect unit for installation damage. If found take ac-
tion and/or repair as appropriate.
Refrigerant Charge
Units are normally shipped as standard with a full re-
frigerant operating charge. Check that refrigerant pres-
sure 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. Repaired
systems and units supplied with a nitrogen holding
charge must be evacuated with a suitable vacuum pump/
recovery unit as appropriate to below 100 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 condenser coils
with the full operating charge as given in the Technical
Data Section.
Valves
Open each compressor suction, economizer, and dis-
charge valves fully (counter-clockwise) then close one
turn of the stem to ensure operating pressure is fed to
the pressure transducers. Open the liquid line service
valve fully and ensure the oil return line ball valve is
open in each system.
Compressor Oil
To add oil to a circuit - connect a YORK hand oil pump
(Part No. 470-10654-000) to the 6 mm (1/4") oil charg-
YORK INTERNATIONAL
COMMISSIONING
ing 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 10 times (delivering ap-
proximately 2 liters [0.4 gal]) to prime the oil system.
The oil level should be between the middle of the lower
and middle of the upper sight glasses of the oil separa-
tor. Approximately 19 liters (5 gallons) is present in the
entire chiller system, with 4 - 8 liters (1-2 gallons) in the
oil separator. If it is necessary to add oil, continue to
stroke the pump until the correct level is achieved.
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 guard is securely fixed.
Isolation/Protection
Verify that 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 Techni-
cal Data Section have 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 the customer power cables are connected cor-
rectly. Ensure that connections of power cables within
the panels to the circuit breakers, terminal blocks or
switch disconnectors are tight.
Grounding
Verify that the unit's protective terminal(s) are properly
connected to a suitable grounding point. Ensure that all
unit internal ground connections are tight.
Overloads
Ensure that the fan overloads settings are correct for
the type of fan fitted.
Supply Voltage
Verify that the site voltage supply corresponds to the
unit requirement and is within the limits given in the Tech-
nical Data Section.
FORM 201.18-NM2
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