York MILLENNIUM 28971AR - Manual (Page 5)

YORK INTERNATIONAL
FORM 201.18-EG1
5
REFRIGERANT CIRCUIT
• Independent refrigerant circuits per compressor,
each using copper refrigerant pipe formed on com-
puter controlled bending machines. This eliminates
over 60% of system piping brazed joints as com-
pared to designs that use fittings, resulting in a highly
reliable and leak resistant system.
• Liquid line components include: manual shut-off
valve with charging port, high adsorption removable
core filter-drier, solenoid valve, sight glass with mois-
ture-indicator, and reliable thermostatic expansion
valves.
• Economizer is a refrigerant to refrigerant, compact
plate-type heat exchanger to maximize chiller ca-
pacity and efficiency by subcooling liquid refrigerant
delivered to the cooler expansion valve. Constructed
of corrosion resistant stainless steel plates formed
to induce turbulent flow and enhance heat transfer,
then oven brazed and pressure tested for reliability.
Designed and constructed in accordance with ASME
and TÜV for 450 PSIG (31 bar). U.L./CSA listed.
• Suction and discharge lines provided with manual
compressor shutoff service valves. Suction line
equipped with closed-cell insulation.
• Oil separators with Design Working Pressure of 450
PSIG (31 bar) and U.L. listing are high efficiency,
augmented aerosol impingement type to maximize
oil extraction without fragile media to break down.An
oil charging valve is included with each refrigerant
circuit.
• Oil cooling provided by dedicated air cooled finned
tube type heat exchanger located in the condenser
section of the machine.
MICROPROCESSOR CONTROLS
• Controls housed in a powder painted steel cabinet
enclosure, equivalent to NEMA 3R/12 (IP55), with
hinged, latched, and gasket sealed, door.
• Liquid crystal 40 character display with text provided
on two lines and light emitting diode backlighting for
outdoor viewing.
• Color coded, 32 button, sealed keypad with sections
for Display, Entry, Setpoints, Clock, Print, Program
and Unit On/Off.
• Standard controls include: brine chilling or thermal
storage, automatic pump down, run signal contacts,
demand load limit from external building automa-
tion system input, remote liquid temperature reset
input, unit alarm contacts, evaporator pump control,
automatic reset after power failure, automatic sys-
tem optimization to match operating conditions, soft-
ware stored in non-volatile memory (EPROM) to
eliminate chiller failure due to AC power failure.
Programmed setpoints retained in lithium battery
backed RTC memory for a minimum 5 years.
• Display – In English (°F and PSIG) or Metric (°C
and Bars) units, and for each circuit:
♦
Return and leaving chilled liquid, and ambient tem-
perature.
♦
Day, date and time. Daily start/stop times. Holi-
day and Manual Override status.
♦
Compressor operating hours and starts. Auto-
matic or manual lead/lag. Lead compressor iden-
tification.
♦
Run permissive status. No cooling load condi-
tion. Compressor run status.
♦
Anti-recycle timer and anti-coincident start timer
status per compressor.
♦
Suction (and suction superheat), discharge, and
oil pressures and temperatures per System.
♦
Percent full load compressor motor current per
phase and average per phase. Compressor ca-
pacity control valve input steps.
♦
Cutout status and set-points for: supply fluid tem-
perature, low suction pressure, high discharge
pressure and temperature, high oil temperature,
low and high ambient, phase rotation safety, and
low leaving liquid temperature.
♦
Unloading limit set-points for high discharge pres-
sure and compressor motor current.
♦
Liquid pull-down rate sensitivity (0.5°F to 5°F/
minute in 0.1°F increments).
♦
Status of: evaporator heater, condenser fans, load
and unload timers, chilled water pump.
♦
“Out of range” message.
♦
Up to 6 fault shut down conditions.
♦
Standard Display Language is English, with Op-
tions for: French, German, Italian, and Spanish.
• Entry – Enter set point changes, cancel inputs, ad-
vance day, change AM/PM.
• Setpoints – Chilled liquid temperature, chilled liq-
uid range, remote reset temperature range.
• Clock – Time, daily or holiday start/stop schedule,
manual override for servicing.
• Print – Operating data or system fault shutdown his-
tory for last six faults, and software version. Print-
outs through an RS-232 port via a separate printer
(by others).
• Program –
♦
Low leaving liquid temperature cutout, 300 to 600
second anti-recycle timer, lag compressor start
time delay, and average motor current unload
point. Liquid temperature setpoint reset signal
from YORK ISN or building automation system
(by others) via: