Fans; Isolation / Protection; Control Panel; Power Connections - York YVAA Installation, Operation & Maintenance Instructions Manual

SECTION 6 - COMMISSIONING
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 which
will result in liquid overfeed and subsequently
damage the compressor. High oil carryover may also cause
liquid to be returned to the compressor, which can
damage the compressor.

Fans

Check that all fans are free to rotate and are not dam-
aged. Ensure blades are at the same height when
rotated. 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 materials
(wire, metal chips, and so on) 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 connections of power cables within the pan-
els 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.
Ensure that all unit internal ground connections are
tight.

Water System

Verify the chilled liquid system has been installed cor-
rectly, and has been commissioned with the correct
direction of water flow through the evaporator. The inlet
should be at the bottom connection on a two pass evapo-
rator. Purge air from the top of the evaporator using the
plugged air vent mounted on the top of the evaporator
body.
Flow rates and pressure drops must be within the limits
given in SECTION 5 - TECHNICAL DATA. Operation
outside of these limits is undesirable and could cause
damage. If main power must be switched OFF for
maintenance or shutdown, precautions must be taken.
98
See Unit Maintenance
Sub-freezing Conditions on Page 100. Before placing
the unit back in service, valves should be opened and power
must be switched on (if power is removed for more than
8 hours) for at least 8 hours (24 hours if ambient
temperature is below 86°F [30°C]) before the unit is
restarted.

Flow Switch

Verify a chilled water flow switch is correctly fitted
in the customer's piping on the evaporator outlet, and
wired into the control panel correctly using shielded
cable.
There should be a straight run of at least five pipe
diameters on either side of the flow switch. The flow
switch should be connected to Terminals 2 and 13 in the
panel.

Temperature Sensor(s)

Ensure that the leaving
sensor is coated with heat conductive compound
(Part No. 013-00890-000) and is inserted to the bottom
of the water outlet sensor well in the evaporator. This
sensor is part of the pump control freeze protection
operation. It provides some freeze protection and must
always be fully inserted in the water outlet sensor well.

Programmed Options

Verify that the options factory-programmed into the
Micro Panel are in accordance with the customer's
order requirements by pressing the OPTIONS key on
the keypad and reading the settings from the display.

Programmed Settings

Ensure the system cutout and operational settings
are in accordance with the operating requirements by
pressing the PROGRAM key.

Date and Time

Program the date and time by first ensuring that the CLK
jumper JP2 on the Chiller Control Board is in the ON
position. Then press the DATE/TIME key and set the
date and time (see "Date/Time and Schedule Keys" on
page 153).

Start/Stop Schedule

Program the daily and holiday start/stop by pressing
the SCHEDULE key (see "Date/Time and Schedule
Keys" on page 153).
FORM 201.28-NM1.1
ISSUE DATE: 1/31/2018
and Shutdown in
liquid temperature
JOHNSON CONTROLS