York MILLENNIUM YCAS 250 Manual Download

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YORK INTERNATIONAL

FORM 201.18-NM3

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 in-
tended 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
invalidate 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
mains 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 U.L. Standard it is the responsibil-
ity of the user to install overcurrent protection devices
between the supply conductors and the power supply
terminals 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.

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.

115 VAC CONTROL SUPPLY TRANSFORMER

A 3-wire high voltage to 115VAC supply transformer
is standard in the chiller. This transformer is mounted
in the Options Cabinet and steps down the high voltage
supply to 115VAC to be used by the Micropanel, Power
Panel components, solenoids, heaters, etc.

The high voltage for the transformer primary is taken
from the chiller input to one of the systems. Fusing is
provided for the transformer.

It is important to check that the cor-
rect primary tapping has been used
and that it conforms to the site high
voltage supply.

Removing high voltage power to the
chiller will remove the 115VAC sup-
ply voltage to the microprocessor cir-
cuitry and the evaporator heater. In
cold weather, this could cause serious
damage to the chiller due to evapora-
tor freeze-up. Do not remove power
unless alternate means are taken to
assure operation of the evaporator
heater.