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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 conjunction
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 1/4" oil charging valve
on the oil separator piping with a length of clean hose or
YORK INTERNATIONAL
COMMISSIONING
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. The oil level
should be between the middle of the lower and middle of
the upper sight glasses of the oil separator. Approximately
19L (5 gallons) is present in the entire chiller system,
with 4 - 8L (1-2 gallons) in the oil separator.
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
Technical 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 prop-
erly 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
Technical Data Section.
Control Transformer
The 3-wire control transformer is mounted in the op-
tions panel. It is important to check that the correct pri-
mary tapping has been used:
With the supply to the unit isolated remove the lid to
the transformer box.
FORM 201.18-NM6
5
39
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