Specifications
ACCESSORIES (Field Installed) (cont)
CONDENSING UNITS
Winter start control is a single-pole, single-throw delay relay
that bypasses the low-pressure switch for approximately 3 min-
utes at unit start-up. The control permits start-up for cooling op-
eration under low load conditions at low-ambient temperatures.
This accessory is recommended on all 538S systems to provide
cooling at outdoor ambient temperatures below 40 F.
Crankcase heater accessory is a clamp-on compressor oil
sump heater. This heater is necessary wherever unit operation
in cooling is anticipated at outdoor ambient temperatures under
40 F.
FAN COIL UNITS
Indoor guard is a decorative wire guard for the ceiling-
suspended (619C) fan coils. The guard mounts over the fan coil
discharge to prevent objects from entering the unit and air
sweep.
Electronic programmable thermostats are available for in-
ceiling cassette (619F) and ceiling-suspended (619C) fan coils.
These commercial-grade thermostats provide 7-day, 4-event-
per-day scheduling. The included subbases provide 3-speed
fan switchover capability.
PHYSICAL DATA — 538S CONDENSING UNITS
UNIT 538S 024 048
NOMINAL CAPACITY (Tons) 24
OPERATING WEIGHT (lb) 159 292
REFRIGERANT TYPE R-22
Control (Cooling) TXV in Condensing Unit
Factory Charge (lb)*
Circuit A 5.0 5.5
Circuit B — 5.5
COMPRESSOR TYPE Copeland Scroll
Quantity...Model 1...ZR23K1 2...ZR23K3
Oil (Recharge) (oz) 25 25
OUTDOOR FAN Propeller, Direct Drive
Rpm 850 850
Diameter (in.)...No. of Blades 18...3 24...3
Pitch (Degrees) 27 24
Motor Hp
1
⁄
8
1
⁄
4
Nominal Air Cfm 1720 3900
OUTDOOR COIL Copper Tube, Aluminum Fin
Face Area (sq ft)...No. of Rows 6.1...2 12.3...2
Fins/in. 15 15
CONTROLS
High-Pressure (psig)
Cut-in 320±20
Cutout 426±7
Low-Pressure (psig)
Cut-in 22±5
Cutout 7±3
Fusible Plug 210 F
Control Voltage (v) 24
REFRIGERANT LINES
Connection Type Sweat
Vapor Supply Line Quantity...OD (in.) 2...
3
⁄
8
4...
3
⁄
8
Vapor Return Line Quantity...OD (in.) 2...
5
⁄
8
4...
5
⁄
8
Maximum Length (ft) 50 50
Maximum Lift Fan Coil (Above Outdoor) (ft) 30† 30†
Maximum Lift Fan Coil (Below Outdoor) (ft) 30† 30†
EXTERNAL FINISH Alpine Mist (Beige)
LEGEND
TXV — Thermostatic Expansion Valve
*Charge is based on 25 ft of interconnecting line.
†Maximum system lift is 30 ft between lowest system component and
highest system component.
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