Electrical Connection; Power Wiring - York MILLENNIUM YCAS Installation Operation & Maintenance

If the ducts from two or more fans are to be combined
into a common duct, back-flow dampers should be fit-
ted in the individual fan ducts. This will prevent recircu-
lation of air when only one of the fans is running.
Units are supplied with outlet guards for safety and to
prevent damage to the fan blades. If these guards are
removed to fit ductwork, adequate alternative precau-
tions must be taken to ensure persons cannot be harmed
or put at risk from rotating fan blades.

ELECTRICAL CONNECTION

The following connection recommendations are intended
to ensure safe and satisfactory operation of the unit.
Failure to follow these recommendations could cause
harm to persons, or damage to the unit, and may invali-
date the warranty.
No additional controls (relays, etc.)
should be mounted in the control
panel. Power and control wiring not
connected to the control panel should
not be run through the control panel.
If these precautions are not followed
it could lead to a risk of electrocution.
In addition, electrical noise could
cause malfunctions or damage the
unit and its controls.
After connection do not switch on
main power to the unit. Some inter-
nal components are live when mains
is switched on and this must only be
done by Authorized persons.

POWER WIRING

All electrical wiring should be carried out in accordance
with local regulations. Route properly sized cables to
cable entries on both sides of the unit.
In accordance with UL Standard it is the responsibility
of the user to install overcurrent protection devices be-
tween the supply conductors and the power supply ter-
minals on the unit.
To ensure that no eddy currents are set up in the power
panel, the cables forming each 3-phase power supply
must enter via the same cable entry.
YORK INTERNATIONAL
All sources of supply to the unit must
be taken via a common point of isola-
tion (not supplied by YORK).
Standard Units with Multi-Point
Power Supply Wiring
Standard units require two 3-phase separately fused 3
wire supplies plus a ground per refrigerant system. One
supply to be connected to each of the power panels.
Connect each of the main 3-phase supplies to the cir-
cuit breakers, non-fused disconnect switches or termi-
nal boards located in the power panels using lug sizes
detailed in the Technical Data Section.
Connect the ground wires to the main protective ground
terminals in each power panel.
Units with Single Point Power Supply Wiring
Units require only one 3-phase plus ground.
Connect the 3-phase supplies to the terminal block or
non-fused disconnect switch located in the options
panel using lug sizes detailed in the Technical Data
Section.
Connect a ground wire to the main protective ground
terminal.
Control Transformer Primary Voltage Tappings
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, check that the tap-
ping used conforms to the site supply voltage.
Remote Emergency Stop Device
If required, a remote emergency stop device can be
wired into the unit. The device should be wired into ter-
minals 31 and 32 in the microprocessor control panel.
CONTROL PANEL WIRING
All wiring to the control panel terminal block is nominal
30 VDC and must be run in shielded cable, with the
shield grounded at the panel end only. Run shielded cable
separately from mains cable to avoid electrical noise
pick-up. Use the control panel cable entry to avoid the
power cables.
FORM 201.18-NM2
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