York MILLENNIUM YCAS 250 Manual Download

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YORK INTERNATIONAL

FORM 201.18-NM3

compartment. Factory wiring is provided from the cir-
cuit breaker to factory supplied terminal blocks in the
power compartments.

Single-Point Power Connection without Circuit
Protection (Not available on 3 and 4 compressor
models)
A single-point supply circuit with field provided pro-
tection is connected to a factory provided terminal block
or non-fused disconnect switch located in the options
compartment. Factory wiring is provided from the ter-
minal block or disconnect switch to factory supplied
terminal blocks in the power compartments.

Control Circuit Terminal Block
A 120V, 20A control circuit power terminal strip lo-
cated in the control panel to accept a field provided
control power supply, rather than the standard factory
mounted control circuit transformer. The supply with
appropriate branch circuit protection in accordance with
applicable Local codes, provides the unit control cir-
cuit power supply via the panel mounted Emergency
Stop Switch.

Building Automation System (BAS) Interface
Provides a means to reset the leaving chilled liquid tem-
perature or percent full load amps (current limiting)
from the BAS (Factory Mounted):

Printed circuit board to accept 4 to 20 mA, 0 to 10 Vdc,
or dry contact closure input from the BAS.

A YORK ISN Building Automation System can pro-
vide a Pulse Width Modulated (PWM) signal direct to
the standard control panel via the standard on-board
RS485 port.

Condenser Coil Protection
The standard condenser coils have aluminium fins, cop-
per tubes, and galvanized steel supports for generally
adequate corrosion resistance. However, these materi-
als are not adequate for all environments.

The following options provide added protection:

Black fin condenser coils - Condenser coils constructed
using black epoxy coated aluminium fin stock for cor-
rosion resistance comparable to copper fin coils in typi-
cal seashore locations.

Copper fin condenser coils – Coils constructed with
corrosion resistant copper fins. Not recommended in
areas where units may be exposed to acid rain.

Phenolic coated condenser coils – Completed con-
denser coil assemblies are covered with a cured Phe-

Entry – Used to confirm Set Point changes, cancel in-
puts, advance day, and change AM/PM.

Setpoints – For setting chilled liquid temperature,
chilled liquid range, remote reset temperature range.

Clock – Used to set time, daily or holiday start/stop
schedule and manual override for servicing.

Print – Used to display or print operating data or sys-
tem fault shutdown history for last six faults. (4 in
YCAS 3 Compressor and YCAS 4 Compressor Mod-
els). Printouts through an RS-232 port via a separate
printer.

Program
For setting low leaving liquid temperature cutout, 300
to 600 second anti-recycle timer, average motor cur-
rent unload point, liquid temperature setpoint reset sig-
nal from YORK ISN or building automation system.

Additional functions (password protected) for program-
ming by a qualified service technician:

Cutouts for low and high ambient, low suction pres-
sure and high discharge pressure, refrigerant type, high
discharge pressure unload setpoint.

ACCESSORIES AND OPTIONS

Multiple Point Power Connection (Standard)
Standard field power wiring connection on all models
is Multiple Point Power Connection. Field provided
power supply circuits, with appropriate branch circuit
protection, are connected to factory provided terminal
blocks, non-fused disconnect switches or circuit break-
ers with lockable external handles located in the two
power compartments.

Single-Point Power Connection with Individual
Circuit Protection
A single-point supply circuit with field provided pro-
tection is connected to a factory provided terminal block
or non-fused disconnect switch located in the options
compartment. Factory wiring is provided from the ter-
minal block or disconnect switch to factory supplied
internal branch circuit breakers with lockable external
handles in the power compartments.

Single-Point Power Connection with Combined
Circuit Protection (Not available on 3 and 4
compressor models)
A single-point supply circuit with field provided pro-
tection is connected to a factory provided circuit breaker
with lockable external handle located in the options