YORK INTERNATIONAL
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• High and low pressure cutouts (one each refriger-
ant circuit)
• Minimum on time for compressors
• Delay between compressor stages
• Anti-short cycle delays (minimum off time) for com-
pressors and supply fan
• Cooling lockout at 7.2°C; -17.7°C if equipped for
low ambient operation
• Air flow proving switch which proves that the fan is
operational
POWER OPTIONS
Single-Point Supply with Terminal Block –
includes
enclosure, terminal-block, and interconnecting wiring to
the compressors. Separate external protection must be
supplied, by others, in the incoming compressor power
wiring. (Do not include this option if either the Single-Point
Non-Fused Disconnect Switch or Single-Point Circuit
Breaker options have been included.)
Single-Point Supply with Non-fused Disconnect
Switch –
A unit-mounted disconnect switch with exter-
nal, lockable handle (in compliance with Article 440-14
of N.E.C.), can be supplied to isolate the unit power volt-
age for servicing. Separate external fusing must be sup-
plied, by others in the power wiring, which must comply
with the National Electric Code and/or local codes. (This
option includes the Single-Point Power connection.)
Dual-Point Supply with Terminal Block –
includes
enclosure, one terminal-block with interconnecting wir-
ing to the supply and exhaust fans and control trans-
former and a second terminal block with interconnect-
ing wiring to the compressors and condenser. Sepa-
rate external protection must be supplied, by others, in
the incoming compressor power wiring.
Convenience Outlet –
an optional 115V convenience
outlet can be provided to power hand tools for servic-
ing the rooftop unit.
CONTROL OPTIONS
Note:
On standard units, mechanical cooling may op-
erate down to 7.2°C.
Low Ambient on System One –
This option includes
low ambient control of the first refrigerant system down
to 0°F through the use of discharge pressure trans-
ducer and a variable speed drive that will vary the speed
of the condenser fan to control condensing pressure.
Mechanical cooling with system two (and three for
YPAL070-095) is locked out below 7.2°C.
Low Ambient on Systems One and Two –
This option
includes low ambient control of the first and second re-
frigerant system down to -17.7°C through the use of dis-
charge pressure transducers and variable speed drives
that will vary the speed of the condenser fans to control
condensing pressure. This option applies to YPAL050-
065 models. On YPAL070-095 models, mechanical cool-
ing with system three is locked out below 7.2°C.
Low Ambient on Systems One, Two and Three –
This option includes low ambient control of the first,
second, and third refrigerant system down to -17.7°C
through the use of discharge pressure transducers and
variable speed drives that will vary the speed of the
condenser fans to control condensing pressure. This
option not available on models YPAL050-065.
Low Ambient on System One + Transducers on
System 2 (and 3 for YPAL070-095) –
on standard
units, mechanical cooling may operate down to 7.2°C.
This option includes low ambient control of the first
refrigerant system down to -17.7°C through the use of
suction and discharge pressure transducers on sys-
tem one. Suction and discharge pressure transduc-
ers are included on remaining system(s) for readout
only. Mechanical cooling with remaining system(s) is
locked out below 7.2°C.
Pressure Transducer with Readout Capability –
suc-
tion and discharge pressure transducers are configured
for pressure readout of all systems. This option is avail-
able only on units without low ambient control. Low am-
bient options already include pressure transducers on
those specific systems. The two options listed directly
before this option describe option combinations of low
ambient and pressure transducer readout options.
Wall-Mount Zone Sensor, No Setpoint Adjustment –
a 1 kOhm thin-film nickel zone sensor for wall mounting.
This zone sensor is for sensing temperature only, and
does not include any setpoint adjustment features.
Wall-Mount Zone Sensor, Scaled Setpoint Adjust-
ment –
a 1 kOhm thin-film nickel zone sensor for wall
mounting. This zone sensor is for sensing tempera-
ture and includes a scaled temperature setpoint ad-
justment feature.
Wall-Mount Zone Sensor, Nonscaled Setpoint Ad-
justment –
a 1 kOhm thin-film nickel zone sensor for
wall mounting. This zone sensor is for sensing tem-
perature and includes a non-scaled (warmer-cooler) set-
point adjustment feature.
Guide Specifications
(continued)
