9
Ultra Air Refrigerated Dryers
201 Series Instruction Manual
Panel Mounted Gauges
A. Refrigerant suction pressure
Indicates pressure on low side of refrigerant compressor. R134a units normally indicate between 28-32
PSIG (1.9-2.2 bar). R22 units normally indicate between 56-62 PSIG (3.8-4.2 bar).
B. Refrigerant discharge pressure (units UA201-125 through UA201-2000)
Indicates pressure on the high side of the refrigeration circuit. R22 units normally indicate 175-275 PSIG
(12-18.9 bar). R134a air cooled units indicate 100-185 PSIG (6.9-12.7 bar).
Water Cooled Models
Cooling water is required for water cooled shell and tube refrigerant condensers. The user is responsible
for piping the water to and from the condenser.
The required water flow depends on the water
temperature (refer to Table 2). A valve sup-
plied with the dryer automatically adjusts the
flow to compensate for variations in water
temperature, water pressure, and dryer air
load.
Cooling water pressures below or tempera-
tures above those listed in Table 2 may
reduce drying capacity. The refrigerant dis-
charge pressure control will shut down the
refrigerant compressor if cooling is inade-
quate.
If the cooling water is dirty, install a strainer
ahead of the condenser inlet. Install shut-off
valves so that the strainer can be drained and
cleaned at regular intervals.
Table 2
Model
H.P.
Water
Water reg., GPM
connect.
City (75ºF) Tower (85ºF)
200
1
3/8 FPT
3.2
6.3
250
1 1/2
3/8 FPT
2
5
300
1 1/2
3/8 FPT
2
5
400
2
3/8 FPT
3.5
8
500
2 1/2
1/2 FPT
4
10
625
3
1/2 FPT
5.5
14
800
4
3/4 FPT
5.5
14
1000
5
3/4 FPT
8.5
22
1200
6
3/4 FPT
8.5
22
1600
9
1 FPT
14
35
1750
9
1 FPT
14
35
2000
9
1 FPT
14
35
REFRIGERATED AIR DRYER INSTRUCTION MANUAL
Controls
A. High-low refrigerant cut-out switch (models 100-2000)
High side setting: R22 - 350 cut-out, Low side setting: R22 - 50 cut-out
Cut out switch senses high and low refrigerant pressure at refrigerant compressor inlet and outlet ports.
B. Liquid line dryer/filter
Filters refrigerant of moisture and any foreign particles. Must be replaced if refrigerant system has maintenance per-
formed on it.
C. Sight glass
Located in the liquid line, indicating liquid refrigerant levels and moisture content.
D. Expansion valve
Senses “low side” (or suction) pressure (temperature). Meters refrigerant flow in the evaporator.
E. Water-regulating valve (water cooled units only)
Senses compressor discharge pressure, regulates water flow to maintain an average 105ºF (40.5ºC) condensing
temperature. Setting is reflected.
F. Electronic drain valve
An electric drain valve is programmed to open and close to automatically drain away condensate.
G. Crank case heater
A safety device which prevents refrigerant migration back to the compressor during shutdown.
H. Hot gas bypass valve
Passes high side gas to low side to maintain a constant suction pressure.
