York YLAA - C. Microprocessor Control Center:

JOHNSON CONTROLS
FORM 150.72-EG6 (516)
58
6. A 20 mesh, serviceable wye-strainer and mechanical couplings shall be provided for
eldinstallationonevaporatorinletpriortostartup.
[Option] Evaporator shall be provided with piping extension kit and mechanical
couplings to extend liquid connection from evaporator to edge of unit. Thermal
dispersiontypeowswitchshallbefactoryinstalledintheevaporatoroutletpipe
extension and wired to the unit control panel. Extension kit nozzle connections shall
be ANSI/AWWA C-606 (grooved) Extension kit pipe insulation and heat trace to be
eldprovided(ifrequired).
B. Air Cooled Condenser:
1. Coils: Condenser coils shall be constructed of a single material to avoid galvanic
corrosion due to dissimilar metals. Coils and headers are brazed as one piece. Inte-
gral sub cooling is included. Coils shall be designed for a design working pressure
of 650 PSIG (45 bar). Condenser coil shall be washable with potable water under
100 psi (7 bar) pressure.
2. Low Sound Fans: Shall be dynamically and statically balanced, direct drive, corro-
sionresistantglassberreinforcedcompositebladesmoldedintoalownoise,full-
airfoil cross section, providing vertical air discharge and low sound. Each fan shall
beprovidedinanindividualcompartmenttopreventcrossowduringfancycling.
Guards of heavy gauge, PVC (polyvinyl chloride) coated or galvanized steel shall
be factory installed.
3. FanMotors:Highefciency,directdrive,6pole,3phase,insulationclass“F”,cur-
rent protected, Totally Enclosed Air-Over (TEAO), rigid mounted, with double sealed,
permanently lubricated, ball bearings.
2.05 CONTROLS
A. General: Automatic start, stop, operating, and protection sequences across the range
of scheduled conditions and transients.
B. Power/Control Enclosure: Rain and dust tight NEMA 3R powder painted steel cabinet
with hinged, latched, and gasket sealed door.
C. Microprocessor Control Center:
1. Automatic control of compressor start/stop, anti-coincidence and anti-recycle tim-
ers, automatic pumpdown at system shutdown, condenser fans, evaporator pump,
evaporator heater, unit alarm contacts, and chiller operation from 0°F to 125°F
(-18°C to 52°C) ambient. Automatic reset to normal chiller operation after power
failure.
2. Remote water temperature reset via 0-10 VDC or 4-20 mA input signal or up to two
steps of demand (load) limiting.
3. Software stored in non-volatile memory, with programmed setpoints retained in lith-
ium-battery -backed real-time-clock (RTC) memory for minimum 5 years.
4. Forty character liquid crystal display, descriptions in English (or Spanish, French,
Italian, or German), numeric data in English (or Metric) units. Sealed keypad with
sections for Setpoints, Display/Print, Entry, Unit Options & clock, and On/Off Switch.
Guide Specifications (Cont'd)