Gardner Denver RDS Series Installation guide

RDS Series
Refrigerated Drye
r
Operations and Maintenance
50-1000 SCFM
Table of Contents
SECTION 1
General Information 2-3
Model Numbers/Serial Numbers
Description of Operation
SECTION 2
Safety Instructions 4
Handling
Installation
Operation
SECTION 3
Specifications 5-9
Dimensions
Specifications
SECTION 4
Installation 10-14
Location
Typical Installation
Piping and Connections
Recommended Filters
Electrical Connections
Drain Valve Time Settings
Remote Contact Hook-up
SECTION 5
Start-up and Shut-down 15
Hot-gas Bypass Valve Adjustment
Procedures
SECTION 6
Maintenance and Repair 16-18
SECTION 7
Troubleshooting Guide 19-21
SECTION 8
Replacement Parts
A
ir Cooled 22-41
Water Cooled 42-57
SECTION 9
Wiring Diagrams 58-66
SECTION 10
Warranty/Claims 67-69
Warranty
Claim Information
Procedures
What is Covered
Claim Form 70
2-2-610 2
ND
EDITION 10/00

Model Number Coding
RDS Series — 50-1000 SCFM
General Information
Section 1
RDS
Flow (SCFM)
50
75
100
125
150
200
250
300
400
500
650
800
1000
A= Air Cooled
W= Water Cooled
(Water Cooled
available on models
150 and larger)
Voltage
1= 115/1/60 1
2= 230/1/60 1
3= 230/3/60 2
4= 460/3/60 2
380/3/50 2
5= 575/3/60 2
150-200 SCFM
2250-1000 SCFM
*Derate Flow by
17% for 50 hz.
C= Remote Operation Contacts (48V Max. Input)
(Shipped Loose)
F= Packaged Filters (Shipped Loose)
N= NEM A 4
P= In/Out Air Pressure Gauges (Shipped Loose)
R= Refrigerant Discharge Pressure Gauge
S= Refrigerant Suction Pressure Gauge
T= Inlet/Outlet Temperature Gauges (Shipped Loose)
S
ERIAL N
U
MBER
Serial Number Coding
TIME/DATE OF MANUFACTURE
-2-

- 3 -
RDS Series — 50-1000 SCFM
Description of Operation
Section 1
Operating principal - The dryers described in
this manual operate on the same principal. A
refrigeration unit reduces the temperature of a chamber
called an evaporator or heat exchanger through which
warm, moist, compressed air is passed. As the air is
passed through the chamber, it is cooled causing
moisture in the air to condense. The condensate is
collected and drained away via an automatic drain valve.
Air circuit - Warm, wet compressed air enters the dryer
and passes through the air to air heat exchanger. Here,
it is cooled by cool, dry air leaving the evaporator. The
pre-cooled air then enters the air to refrigerant heat
exchanger (evaporator ) where it is cooled to a temp
of approximately 33-35° F. Cooling in the evaporator
causes water vapor in the air to condense (removed
from the system by means of an automatic drain).
Refrigerant circuit - Refrigerant (R-22) gas is pumped
at high pressure by a compressor to an air or water
cooled condenser where it is cooled and condensed
to a liquid form. The liquid is forced through a metering
device where the resulting pressure drop causes the
boiling point of the refrigerant to drop. Low pressure
liquid refrigerant enters the evaporator where heat from
the entering air is transferred causing it to boil and
become a low pressure, cool gas. A portion
of the liquid may be bypassed through a liquid injection
circuit that keeps the compressor cool under conditions
of high load and ambient temperatures. The low
pressure gas is returned to the compressor, where
it is re-compressed and begins the cycle again.
Figure 1.2 Refrigeration Circuit
HOT GAS
V
A
LVE
HEAT
EXCHANGER
AIR IN
A
IR TO
A
IR HEAT
E
X
CHANGER
AIR OUT
DRAIN
COMPRESSOR CONDENSER
METERING
DEVICE

- 4 -
RDS Series — 50-1000 SCFM
Safet
y
Instructions
Section 2
PANELS,ETC. ARE NOT STRONG ENOUGH TO HANDLE
THE WEIGHT OF THE DRYER. DO NOT LIFT THE
DRYER ANYWHERE EXCEPT THE DESIGNATED
PLACES. PIPING, PERSONAL INJURY AND/OR
EQUIPMENT DAMAGE COULD RESULT.
ENSURE THAT ALL EQUIPMENT BEING USED TO LIFT
THE DRYER IS CAPABLE OF LIFTING THE WEIGHT OF
THE DRYER. NYLON STRAPS AND SOFT RIGGING
DEVICES SHOULD BE USED WHENEVER POSSIBLE
TO PROTECT THE COMPONENTS AND FINISH OF
THE DRYER. IF THE DRYER IS BEING
TRANSPORTED OVERHEAD
FAILURE TO FOLLOW THE SAFETY INSTRUCTIONS
IN THIS SECTION COULD LEAD TO EQUIPMENT
DAMAGE, PERSONAL INJURY OR DEATH, OR BOTH.
MANUFACTURER WILL NOT BE HELD LIABLE FOR
FAILURE TO FOLLOW THESE INSTRUCTIONS AND
GUIDELINES.
Before starting or installing the dryer, be sure that
all power to the unit is off, valves are shut, and the air
circuit is at atmospheric pressure. DO NOT remove,
repair, or replace any component, control, filter, or part,
while the air circuit is energized or under pressure. Turn
off the main to the dryer and de-pressurize the unit before
starting installation or maintenance procedures.
Pressure vessels need to be protected by safety relief
valves. Refer to OSHA 1910.169 Paragraph B
subparagraph (3) and ASME Boiler and Pressure Vessel
code, section VIII, Division 1, UG - 125 through UG - 136.
Also check government regulations, i.e.
state and local codes.
When installing this equipment, comply with National
Electric Code and any applicable federal, state, and local
codes. Make sure that all customer supplied wiring and
electrical devices are properly sized to handle the
electrical requirements of the dryer.
MANUFACTURER WILL NOT BE RESPONSIBLE
FOR DAMAGE TO EQUIPMENT AS A RESULT OF
IMPROPER WIRING OR ELECTRICAL
INSTALLATION. IT IS THE CUSTOMERS
RESPONSIBILITY TO ENSURE THAT THE
ELECTRICAL INSTALLATION IS CORRECT
AND UP TO APPLICABLE CODES.
When installing the dryer, ensure that the NEMA
rating of the control box is applicable to the
installation.
Dryer is rated NEMA 1. (NEMA 4 OPTIONAL)
Read and understand the MSDS and first aid
instructions for Refrigerant 22 (R-22)
2.2 Installation
2.1 Handling Figure 2.1.1 Approved Lifting and Moving Method.
2.3 Operation
DO NOT OPERATE THE DRYER ABOVE THE
STATED WORKING PRESSURE (SEE
SPECIFICATION TABLE). FAILURE, INJURY
AND EQUIPMENT DAMAGE COULD RESULT.
USE THIS DRYER FOR COMPRESSED
AIR ONLY.
AIR FROM THIS DRYER IS NOT SUITABLE FOR
BREATHING AIR SYSTEMS WITHOUT
FURTHER FILTRATION AND TREATMENT.

- 5 -
Capacity Fa
n
St
d
Differential Lengt
h
Width Height IN/OUT Drai
n
Wt.
Model SCFM BTU CF
M
V
oltag
e
HP Kw Pressur
e
inches inches inches
A
B
C
D
E
F
G H I Conn. NP
T
Conn. NP
T
l
b
RDS50 50 6000 349 115-230/1/60 .50 .74 4.7 17 16 32 15.97 17.1 26.78 5.24 7.28 8.84 10.75 10.79 12.79 3/4" 1/4" 140
RDS75 75 6000 540 115-230/1/60 .50 .80 3.1 18 19 38 17.8 19.2 31.9 6.1 8.5 10.5 12.9 13.9 15.9 3/4" 1/4" 160
RDS100 100 7200 542 115-230/1/60 .50 1.0 1.8 21 19 41 18.8 20.2 35.1 6.1 8.5 10.5 12.9 13.9 15.9 1" 1/4" 175
RDS125 125 12000 542 115-230/1/60 .50 1.4 2.7 21 19 41 18.8 20.2 35.1 6.1 8.5 10.5 12.9 13.9 15.9 1" 1/4" 185
RDS150 150 12000 886 115-230/1/60 .75 1.2 3 24 19 44 21.9 23.3 38.2 6.1 8.5 10.5 12.9 13.9 15.9 1" 1/4" 205
RDS200 200 13800 1079 115-230/1/60 1.0 1.3 3 27 22 46 23.8 25.2 40.1 7.3 9.7 11.7 14.1 14.7 16.7 1-1/2" 1/4" 285
RDS250 250 14800 1079 230-460/3/60 1.0 1.3 5 27 22 46 23.8 25.2 40.1 7.3 9.7 11.7 14.1 14.7 16.7 1-1/2" 1/4" 295
RDS300 300 21600 1556 230-460/3/60 1.5 1.5 1.2 33 26 45 29.0 35.1 32.7 15.6 N/A 3.1 10.4 37.8 21.9 1-1/2" 1/4" 440
RDS400 400 23400 1867 230-460/3/60 2.0 1.6 2 33 26 45 29.0 35.1 32.7 15.6 N/A 3.1 10.4 37.8 21.9 2" 1/4" 460
RDS500 500 28806 1867 230-460/3/60 2.5 2.5 1.6 33 26 45 29.0 34.8 32.7 15.9 N/A 3.1 10.1 38.1 21.9 2" 1/4" 480
RDS650 650 42000 2742 230-460/3/60 3.0 3.7 2.8 33 26 45 29.0 34.8 32.7 15.9 N/A 3.1 10.1 38.1 21.9 2" 1/4" 550
RDS800 800 54000 3558 230-460/3/60 4.0 4.0 1.6 36 30 51.6 33.5 40.2 46.1 14.5 N/A 3.1 8.3 43.8 25.9 3" 1/4" 600
RDS1000 1000 67200 3558 230-460/3/60 5.0 4.9 2.5 36 30 51.6 33.5 40.2 46.1 14.5 N/A 3.1 8.3 43.8 25.9 3" 1/4" 620
3.0 Dimensions
RDS Series — 50-1000 SCFM
S
p
ecifications
Section 3
RDS300-1000
BACK VIEW
RDS50-250
BACK VIEW

- 6 -
Comp. Comp. Comp. Minimum Fan Motor
Model Flow Voltage RLA LRA HP Circuit AMPs FLA (EA)
RDS50A-1 50 SCFM 115/60/1 5.80 28.0 0.46 15 0.50
RDS50A-2 50 SCFM 208-230/60/1 2.90 20.0 0.54 15 0.30
RDS75A-1 75 SCFM 115/60/1 5.80 28.0 0.46 15 1.20
RDS75A-2 75 SCFM 208-230/60/1 3.50 20.0 0.46 15 0.57
RDS100A-1 100 SCFM 115/60/1 7.30 34.0 0.54 15 0.70
RDS100A-2 100 SCFM 208-230/60/1 3.60 20.0 0.54 15 0.30
RDS125A-1 125 SCFM 115/60/1 10.50 35.0 0.83 15 0.70
RDS125A-2 125 SCFM 208-230/60/1 5.10 22.4 0.83 15 0.30
RDS150A-1 150 SCFM 115/60/1 9.50 47.0 0.83 15 0.70
RDS150A-2 150 SCFM 208-230/60/1 4.60 28.0 0.83 15 0.30
RDS150A-3 150 SCFM 230/60/3 5.70 58.0 0.83 15 0.30
RDS200A-1 200 SCFM 115/60/1 10.50 67.0 1.08 15 0.70
RDS200A-2 200 SCFM 208-230/60/1 4.60 31.0 1.08 15 0.30
RDS250A-3 250 SCFM 230/60/3 5.60 58.0 1.43 15 0.30
RDS250A-4 250 SCFM 460/60/3 - 380/3/50 2.50 17.4 1.43 15 0.70
RDS250A-5 250 SCFM 575/60/3 2.50 17.4 1.43 15 0.70
RDS300A-3 300 SCFM 230/60/3 6.00 50.0 0.91 15 0.25
RDS300A-4 300 SCFM 460/60/3 - 380/3/50 2.80 25.0 1.83 15 0.70
RDS300A-5 300 SCFM 575/60/3 2.60 25.0 1.83 15 0.70
RDS400A-3 400 SCFM 230/60/3 6.80 50.0 2.00 15 0.30
RDS400A-4 400 SCFM 460/60/3 - 380/3/50 3.20 25.0 2.00 15 0.70
RDS400A-5 400 SCFM 575/60/3 2.90 26.0 2.75 15 0.70
RDS500A-3 500 SCFM 230/60/3 9.50 71.0 2.50 15 0.70
RDS500A-4 500 SCFM 460/60/3 - 380/3/50 4.20 36.0 2.50 15 0.70
RDS500A-5 500 SCFM 575/60/3 3.20 26.0 2.50 15 0.60
RDS650A-3 650 SCFM 230/60/3 14.60 92.0 3.00 20 1.40
RDS650A-4 650 SCFM 460/60/3 - 380/3/50 7.20 46.0 3.00 15 0.70
RDS650A-5 650 SCFM 575/60/3 5.20 44.0 3.00 15 0.60
RDS800A-3 800 SCFM 230/60/3 17.00 123.0 5.00 23 1.70
RDS800A-4 800 SCFM 460/60/3 - 380/3/50 7.10 62.0 5.00 15 0.50
RDS800A-5 800 SCFM 575/60/3 4.70 50.0 5.00 15 0.70
RDS1000A-3 1000 SCFM 230/60/3
RDS1000A-4 1000 SCFM 460/60/3 - 380/3/50 7.20 70.0 6.00 20 0.70
RDS1000A-5 1000 SCFM 575/60/3 6.70 54.0 6.00 15 0.70
S
p
ecifications
RDS Series — 50-1000 SCFM Section 3
3.1 Air-Cooled Specifications Chart

- 7 -
S
p
ecifications
RDS Series — 50-1000 SCFM Section 3
3.2 Air-Cooled Specifications Chart
UNIT MAX CHARGE* STANDARD OPERATING CONDITIONS HEAT REJECTION LOW SIDE HIGH SIDE
MODEL FLA FUSE (R-22) INLET AIR PRESS. / INLET AIR TEMP. / AMBIENT AIR TEMP. BTU/HR TEST PRESS. TEST PRESS.
RDS50A-1 6.5 15 16 oz. 100 PSIG / 100OF / 100OF 3300 190 PSIG 400 PSIG
RDS50A-2 3.6 15 16 oz. 100 PSIG / 100OF / 100OF 3300 190 PSIG 400 PSIG
RDS75A-1 7.0 15 24 oz. 100 PSIG / 100OF / 100OF 4900 190 PSIG 400 PSIG
RDS75A-2 4.2 15 24 oz. 100 PSIG / 100OF / 100OF 4900 190 PSIG 400 PSIG
RDS100A-1 8.3 15 32 oz. 100 PSIG / 100OF / 100OF 6600 190 PSIG 400 PSIG
RDS100A-2 4.0 15 32 oz. 100 PSIG / 100OF / 100OF 6600 190 PSIG 400 PSIG
RDS125A-1 11.5 15 33 oz. 100 PSIG / 100OF / 100OF 8200 190 PSIG 400 PSIG
RDS125A-2 5.5 15 33 oz. 100 PSIG / 100OF / 100OF 8200 190 PSIG 400 PSIG
RDS150A-1 10.5 15 36 oz. 100 PSIG / 100OF / 100OF 9800 190 PSIG 400 PSIG
RDS150A-2 5.0 15 36 oz 100 PSIG / 100OF / 100OF 9800 190 PSIG 400 PSIG
RDS150A-3 6.0 15 64 oz. 100 PSIG / 100OF / 100OF 9800 190 PSIG 400 PSIG
RDS200A-1 11.5 15 58 oz. 100 PSIG / 100OF / 100OF 13000 190 PSIG 400 PSIG
RDS200A-2 5.0 15 58 oz. 100 PSIG / 100OF / 100OF 13000 190 PSIG 400 PSIG
RDS250A-3 5.8 15 64 oz. 100 PSIG / 100OF / 100OF 16000 190 PSIG 400 PSIG
RDS250A-4 3.0 15 64 oz. 100 PSIG / 100OF / 100OF 16000 190 PSIG 400 PSIG
RDS250A-5 3.0 15 64 oz. 100 PSIG / 100OF / 100OF 16000 190 PSIG 400 PSIG
RDS300A-3 7.0 15 48 oz. 100 PSIG / 100OF / 100OF 20000 190 PSIG 400 PSIG
RDS300A-4 3.5 15 48 oz. 100 PSIG / 100OF / 100OF 20000 190 PSIG 400 PSIG
RDS300A-5 2.6 15 48 oz. 100 PSIG / 100OF / 100OF 20000 190 PSIG 400 PSIG
RDS400A-3 7.2 15 60 oz. 100 PSIG / 100OF / 100OF 26000 190 PSIG 400 PSIG
RDS400A-4 3.7 15 60 oz. 100 PSIG / 100OF / 100OF 26000 190 PSIG 400 PSIG
RDS400A-5 3.8 15 60 oz. 100 PSIG / 100OF / 100OF 26000 190 PSIG 400 PSIG
RDS500A-3 10.5 15 68 oz. 100 PSIG / 100OF / 100OF 33000 190 PSIG 400 PSIG
RDS500A-4 5.0 15 68 oz. 100 PSIG / 100OF / 100OF 33000 190 PSIG 400 PSIG
RDS500A-5 3.7 15 68 oz. 100 PSIG / 100OF / 100OF 33000 190 PSIG 400 PSIG
RDS650A-3 16.0 20 100 oz. 100 PSIG / 100OF / 100OF 43000 190 PSIG 400 PSIG
RDS650A-4 8.0 15 100 oz. 100 PSIG / 100OF / 100OF 43000 190 PSIG 400 PSIG
RDS650A-5 6.0 15 100 oz. 100 PSIG / 100OF / 100OF 43000 190 PSIG 400 PSIG
RDS800A-3 19.0 30 120 oz. 100 PSIG / 100OF / 100OF 52000 190 PSIG 400 PSIG
RDS800A-4 8.1 15 120 oz. 100 PSIG / 100OF / 100OF 52000 190 PSIG 400 PSIG
RDS800A-5 5.8 15 120 oz. 100 PSIG / 100OF / 100OF 52000 190 PSIG 400 PSIG
RDS1000A-3
RDS1000A-4 8.0 20 120 oz. 100 PSIG / 100OF / 100OF 66000 190 PSIG 400 PSIG
RDS1000A-5 8.0 15 120 oz. 100 PSIG / 100OF / 100OF 66000 190 PSIG 400 PSIG

- 8 -
COMP. COMP. COMP. MINIMUM UNIT
MODEL FLOW VOLTAGE RLA LRA HP CIRCUIT AMPS FLA
RDS150W-1 150 SCFM 115/60/1 9.5 47.0 0.83 15 10.5
RDS150W-2 150 SCFM 208-230/60/1 5.1 28.0 0.83 15 5.5
RDS200W-1 200 SCFM 115/60/1 10.5 67.0 1.08 15 11.5
RDS200W-2 200 SCFM 208-230/60/1 5.4 31.0 1.08 15 6.0
RDS250W-3 250 SCFM 230/60/3 5.6 58.0 1.43 15 6.0
RDS250W-4 250 SCFM 460/60/3 - 380/3/50 2.5 17.4 1.43 15 3.0
RDS250W-5 250 SCFM 575/60/3
RDS300W-3 300 SCFM 230/60/3 6.0 50.0 0.91 15 7.0
RDS300W-4 300 SCFM 460/60/3 - 380/3/50 2.8 25.0 1.83 15 3.5
RDS300W-5 300 SCFM 575/60/3
RDS400W-3 400 SCFM 230/60/3
RDS400W-4 400 SCFM 460/60/3 - 380/3/50 3.2 25.0 2.00 15 3.7
RDS400W-5 400 SCFM 575/60/3
RDS500W-3 500 SCFM 230/60/3 9.5 71.0 2.50 15 10.5
RDS500W-4 500 SCFM 460/60/3 - 380/3/50 4.2 36.0 2.50 15 5.0
RDS500W-5 500 SCFM 575/60/3 4.6 26.0 2.50 15 5.3
RDS650W-3 650 SCFM 230/60/3
RDS650W-4 650 SCFM 460/60/3 - 380/3/50 7.2 46.0 3.00 15 8.0
RDS650W-5 650 SCFM 575/60/3
RDS800W-3 800 SCFM 230/60/3
RDS800W-4 800 SCFM 460/60/3 - 380/3/50 8.5 62.0 5.00 15 9.4
RDS800W-5 800 SCFM 575/60/3
RDS1000W-3 1000 SCFM 230/60/3
RDS1000W-4 1000 SCFM 460/60/3 - 380/3/50 10.3 70.0 6.00 15 10.8
RDS1000W-5 1000 SCFM 575/60/3
S
p
ecifications
RDS Series — 50-1000 SCFM Section 3
3.3 Air-Cooled Specifications Chart

- 9 -
RDS Series — 50-1000 SCFM Section 3
3.4 Water-Cooled Specifications Chart
S
p
ecifications
MAX CHARGE* STD OPERATING STD OPERATING STD OPERATING LOW SIDE HIGH SIDE
MODEL FUSE (R-22) INLET AIR PRESS. INLET AIR TEMP. AMBIENT AIR TEMP. TEST PRESS. TEST PRESS.
RDS150W-1 15 27 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS150W-2 15 27 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS200W-1 15 36 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS200W-2 15 36 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS250W-3 15 52 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS250W-4 15 52 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS250W-5
RDS300W-3 15 30 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS300W-4 15 30 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS300W-5
RDS400W-3
RDS400W-4 15 32 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS400W-5
RDS500W-3 15 40 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS500W-4 15 40 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS500W-5 20 40 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS650W-3
RDS650W-4 15 52 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS650W-5
RDS800W-3
RDS800W-4 20 64 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS800W-5
RDS1000W-3
RDS1000W-4 20 54 oz. 100 PSIG 100OF 100OF 190 PSIG 400 PSIG
RDS1000W-5

- 10 -
RDS Series —50-1000 SCFM
Installing the Dryer
Section 4
4.0 Location
DO NOT INSTALL DRYER IN AN ENVIRONMENT OF
CORROSIVE CHEMICALS, EXPLOSIVE GASSES,
POISONOUS GASSES, STEAM HEAT, AREAS OF
HIGH AMBIENT CONDITIONS, OR EXTREME DUST
AND DIRT.
Install the dryer in a protected, well ventilated area
where the ambient temperatures are between
40 degrees and 100 degrees F. The dryer will
generate the amount of heat listed in the heat rejection
column of the specification table. It must be installed in
an area that has ventilation and air flow sufficient to
handle the required heat removal.
FAILURE TO INSTALL DRYER IN THE PROPER
AMBIENT CONDITIONS WILL AFFECT THE DRYERS
ABILITY TO CONDENSE REFRIGERANT GAS. THIS
CAN CAUSE HIGHER LOADS ON THE
COMPRESSORS, LOSS OF DRYER EFFICIENCY
AND PERFORMANCE, OVERHEATED CONDENSER
FAN MOTORS, ELECTRICAL COMPONENT
FAILURE, AND DRYER FAILURE DUE TO THE
FOLLOWING: COMPRESSOR LOSS, FAN MOTOR
FAILURE, AND ELECTRICAL COMPONENT
FAILURE. FAILURES OF THIS TYPE WILL AFFECT
WARRANTY CONSIDERATIONS.
Install the dryer in a clean, dry, non-corrosive
environment. Clearance around the dryer should
be no less than 12" on all sides to ensure room for
maintenance and proper air circulation to air cooled
components. Some jurisdictions have codes requiring
specific clearances around equipment. Check with
all local authorities to ensure compliance with all
applicable state, local, and national codes.
Refrigerated air dryers have water present in them at all times.
Fumes from compounds such as formaldehyde, carbon dioxide,
sulfur compounds, and ammonia will combine with water in the
dryer to form acids such as carbonic, sulfuric, and nitric which
are extremely corrosive to the dryer. Install the air inlet to the air
compressor in a manner that ensures that corrosive fumes are
not introduced into the air system.
DRYER FAILURE DUE TO ACID OR CORROSIVE SUBSTANCE
ATTACK IS CONSIDERED OWNER ABUSE AND WILL NOT
BE COVERED AS A WARRANTY ITEM. IT IS THE USERS
RESPONSIBILITY TO ENSURE THAT AIR SUPPLIES ARE
CLEAN AND CONTAMINANT FREE.
Install the dryer indoors. Dryers are not meant to be
installed outdoors exposed to the weather. If the dryer
must be installed outdoors, it must be in a weatherproof
enclosure that provides for adequate air flow to the dryer.
Position the dryer in an upright position on a solid, level,
vibration free surface capable of supporting the dryers
weight. Rubber isolation pads should be installed between
the dryer and the surface it is placed on.
Connect the inlet and outlet piping to the dryer using the
markings on the dryer as a guide. Pipe size for dryer is
specified in the specification table. Piping should be full
flow if possible with the least amount of turns, bends, or
reductions. If the dryer is connected to a machine with
excessive vibration, flexible connections should be used
to isolate the dryer from the rest of the system.
Use dielectric unions to isolate copper from iron piping and
reduce possibility of electrolytic action on pipes and other
iron components.
All pipe should be deburred and threaded to a proper depth
and length before installation. Threads should be inspected
for cleanliness and depth of cut. Good quality pipe
compound should be used in the makeup of joints to
ensure a good, airtight fit of piping components.
Pipe should be anchored separately from the dryer. At no
time should the dryer be expected to support the weight or
load of the pipe. Acceptable pipe mounting devices would
be unistrut supports anchored to walls, hangers suspended
from ceilings, or pedestals mounted from the floor. Be sure
all pipe installation conforms to all building and fire codes.
4.1 Piping and Connections
Caution
Caution

- 11 -
RDS Series — 50-1000 SCFM
Installin
g
the Dr
y
e
r
Section 4
4.1 Piping and Connections Cont.
The side panels of the dryer slide out to allow access for
maintenance. Keep the area directly over the dryer clear
of piping, pipe hangers, or pipe supports so that the panels
can be removed.
NOTE:It is not possible to switch the dryer between
MANUAL and AUTO modes once it is started in either mode.
To switch the dryer between modes, use the following
procedure.
1. Turn the dryer off at the “STOP” switch on the
font control panel.
2. De-energize the dryer from the main power source.
3. Toggle the MANUAL/AUTO switch to the desired mode.
4. Re-apply the power to the dryer.
5. Turn the dryer on by depressing the “on” button
on the control panel.
Water Cooled Unit Operating Instructions
Water-cooled units are designed using 85 Deg F inlet water.
Make the condenser water connections to the dryer
According to the inlet and outlet labels on the inlet and
outlet lines. The water-regulating valve is located on the
inlet line. Unions and isolation valves should be installed on
the inlet and outlet for service and isolation purposes.
NOTE:Water used in water cooled condensers should be
treated or severe condenser fouling and resulting loss of
heat transfer could occur.
This will greatly affect dryer performance and efficiency.
Units employing water -cooled condensers use a head
pressure controller (water regulating valve) to regulate the
high side pressure of the refrigeration system. The valve has
a capillary tube that is connected to the high side and
measures high side or head pressure. As the pressure
increases, force on a diaphragm inside the valve is increased
causing the valve to open. This action increases water flow
to the condenser, creating more heat removal potential and
lowering the high side pressure. As the pressure drops, the
valve closes and high side pressure is allowed to increase.
By monitoring pressure and adjusting water flow, the valve
regulates the head pressure.
Water regulating valves are set at the factory and do not
normally need any additional adjustment. If for some reason
the unit needs adjustment, use the following procedures.
Temperature procedure (setting the valve using temperature)
1. Ensure that the dryer is on and operating before making
theses adjustments.
2. Attach the probe of an electronic thermometer or other
temperature sensing device to the outlet water line on the
condenser. Readings must be taken on the Fahrenheit
scale.
3. Place a wrench on the adjusting nut at the top of the
water-regulating valve.
4. Turn the adjusting nut in the direction indicated on the
top of the valve to increase or decrease water flow.
Adjust the nut until the water temperature on the
thermometer reads 105 Deg F with a minimum of
fluctuation.
Pressure procedure (Setting the valve using pressure)
1. Ensure that the dryer is on and operating before
making these adjustments.
2. Install a set of manifold gauges on the high side of the
refrigeration system. There is a Schraeder connection
(access valve) for this purpose.
3. Place a wrench on the adjusting nut at the top of the
water-regulating valve.
4. Turn the adjusting nut in the direction that is indicated
on the top of the valve to increase or decrease water
flow. Adjust the nut until the high side refrigerant
pressure is 225 PSI with a minimum of fluctuation.
REQUIRED WATER FLOW
MODEL #GPM@75 GPM@80 GPM@85 GPM@100
RDS50 0.4 0.5 0.7 2.7
RDS75 0.5 0.7 0.8 3.3
RDS100 0.6 0.8 1.0 3.8
RDS150 0.7 0.9 1.1 4.4
RDS200 0.8 1.0 1.2 5.0
RDS250 1.0 1.2 1.5 6.0
RDS300 1.3 1.6 2.0 7.9
RDS400 1.7 2.1 2.6 10.3
RDS500 2.2 2.6 3.3 13.1
RDS650 2.8 3.4 4.3 17.0
RDS800 3.4 4.1 5.2 20.6
RDS1000 4.4 5.2 6.5 26.2

- 12 -
Dryer Model Pre-Filter After-Filter
RDS50 FSH65P FSH65C
RDS75 FSH75P FSH75C
RDS100 FSH100P FSH100C
RDS125 FSH150P FSH150C
RDS150 FSH150P FSH150C
RDS200 FSH225P FSH225C
RDS250 FSH300P FSH300C
RDS300 FSP300P FSH300C
RDS400 FSH450P FSH450C
RDS500 FSH650P FSH650C
RDS650 FSH650P FSH650C
RDS800 FSH1000P FSH1000C
RDS1000 FSH1000P FSH1000C
RDS Series — 50-1000 SCFM
Installing the Dryer
Section 4
4.3 Electrical Connections
SERIOUS PERSONAL INJURY AND DAMAGE TO THE
DRYER WILL OCCUR IF THE DRYER IS CONNECTED
TO A POWER SOURCE OTHER THAN THE VOLTAGE
LISTED ON THE DATA TAG OF THE DRYER. THE
MANUFACTURER IS NOT LIABLE FOR DAMAGE DUE
TO IMPROPER WIRING, PROTECTION, OR
ELECTRICAL SERVICE INSTALLATION.
WHEN INSTALLING ELECTRICAL SERVICE TO THIS
MACHINE, COMPLY WITH THE NATIONAL ELECTRIC
CODE AS WELL AS STATE AND LOCAL BUILDING
CODES.
A
LL SINGLE
PHASE UNITS
View of Connections With Lid Removed.
Figure 4.3.1 Wiring Connections High Voltage
Caution
FAILURE TO INSTALL THE PROPER ELECTRICAL
PROTECTION CAN RESULT IN PERSONAL INJURY,
FIRE, EQUIPMENT DAMAGE, OR DEATH. THE
MANUFACTURER IS NOT RESPONSIBLE FOR
DAMAGE OR INJURY CAUSED BY LACK OF OR
IMPROPERLY INSTALLED ELECTRICAL
PROTECTION.
ON RDS800,1000,1250 AND 2800 MODELS
VERIFICATION OF PROPER COMPRESSOR
ROTATION MUST BE MADE!
ROTATION MUST BE OBSERVED SO THAT:
1. FANS PULLING AIR INTO DRYER.
2. SUCTION PRESSURE DROPS AT START-UP.
3. COMPRESSOR DOES NOT MAKE EXCESSIVE NOISE.
See wiring diagram at the end of the manual for electrical
connections to the dryer. Check model number to verify
that proper voltage is being supplied to the dryer. Refer
to figure 4.3.1 for correct wire connections.
Air dryers are part of a complete air treatment system
that includes filters, moisture separators, etc. To achieve
maximum benefit from the dryer, install proper filtration.
Coalescing filters should be used in conjunction with a
good particulate filter. The particulate filter is used to
extend the life and the function of the coalescing element.
Recommended filters are as follows.
4.2 Recommended Filters
A
LL THREE
PHASE UNITS

Model Interval Duration Interval Duration
50 SCFM I1 S3 132 1.5
75 SCFM I1 S3 132 1.5
100 SCFM I1 S3 132 1.5
125 SCFM I1 S3 132 1.5
150 SCFM I1 S3 132 1.5
200 SCFM I1 S3 132 2.5
250 SCFM I1 S2 132 2.5
300 SCFM I1 S1 132 3.5
400 SCFM I1 S1 132 3.5
500 SCFM I1 S1 132 3.5
650 SCFM I1 S3 132 1.5
800 SCFM I1 S3 132 1.5
1000 SCFM I1 S2 132 2.5
AUXILIARY AND REMOTE CONTACTS - THE DRYER IS
EQUIPPED WITH AUXILIARY AND REMOTE CONTACTS FOR
INTERFACE TO CUSTOMER CONTROLS AND AUTOMATION
SYSTEMS. THESE CONTACTS CAN BE USED FOR REMOTE
START AND ALARMS. CONNECT THESE CONTACTS
A
CCORDING TO THE FOLLOWING DIAGRAM.
RDS Series —50-1000 SCFM
Installing the Dryer
Section 4
4.4 Drain Valve Timer Options 4.5 O
p
tional – Remote Contacts
Jumpe
r
Selection
Drain
Timing (Sec.)
POWER SUPPLY
48VAC/DC MAX.
A
LARM SIGNAL OUTPUT
(ON WHEN DRYER IS MALFUNCTIONING)
POWER SUPPLY
48VAC/DC MAX.
DEW POINT ALARM SIGNAL OUTPUT
(ON WHEN DEW POINT IS ABNORMAL)
POWER SUPPLY
48VAC/DC MAX.
RUNNING SIGNAL OUTPUT
(ON WHEN DRYER IS RUNNING)
NO-VOLTAGE
CONTACT

- 14 -
The remote option (option C) allows start/stop and
alarm monitoring functions from a remote location.
The option is universal for all RDS dryer products.
There are four terminal on the remote option board.
Terminals 1:5 are active and are used for remote
start/stop functions. Terminals 2:6, 3:7, and 4:8 are dry
and used for remote alarm monitoring functions. Follow
the procedures outlined below to install the remote option.
DEENERGIZE THE AIR DRYER AT THE MAIN SOURCE
OF ELECTRICAL SUPPLY BEFORE BEGINNING
INSTALLATION OF REMOTE OPTION. FAILURE TO DO
SO COULD RESULT IN PERSONAL INJURY AND/OR
EQUIPMENT DAMAGE.
1. Install option board in the rear section of the electrical
compartment of the dryer. There are two predrilled holes
that are designed to accept self tapping or sheet metal
screws. The terminals on the control board should face the
rear of the dryer when properly installed.
2. Remove jumper (JP1) from the rear of the main dryer solid
state control board. JP1 location is detailed in the dryer
Operation and Maintenance manual. Remote option will
not work unless JP1 is removed.
3. Plug the “pigtail” provided with the remote option into the
blank jack on the back of the main control board. The
switch on the remote board must be in the REMOTE
position for the option to work properly.
4. At this point, the option is installed and ready for customer
supplied connections. Please refer to the diagram of the
option terminal board when making connections.
PLEASE NOTE: Contact Ratings on
Remote Option Board are 48 VAC/DC.
RDS Series —50-1000 SCFM
Installin
g
the Dr
y
e
r
Section 4
4.6.1 Installation Instruction for
Remote Option
5. Terminals 1 and 5 are connected. Power is supplied
to one side of the contacts from the solid state control
board and parallels the on off function on the dryer.
When a switch is installed between 1 and 5 the dryer
will turn on when the switch is closed and shut off
when the switch is open.
6. Terminals 2 and 6 are connected to dry contacts on the
control board that close when the dryer is on and can be
used to give a remote RUN indication. Connect customer
supplied power to number 2 side on the terminal. Connect
number 6 side to customer supplied device such as light,
relay coil. etc. that will be used to give remote indication.
7. Terminals 3 and 7 are connected to dry contacts on the
control board that close when a HIGH REFRIGERANT
TEMP OR HIGH TEMP alarm is sensed and can be used
to give a remote high temperature indication. Connect
customer supplied power to number 3 side on the terminal.
Connect number 7 side to customer supplied device
such as light, relay coil. etc. that will be used to give
remote indication.
8. Terminals 4 and 8 are connected to dry contacts on the
control board that close when a HIGH DEWPOINT alarm is
sensed and can be used to give a remote high dewpoint
indication. Dewpoint alarm will not activate until 15 minutes
after the dryer is turned on to allow it to reach operating
conditions. Connect customer supplied power to number
4 side on the terminal. Connect number 8 side to customer
supplied device such as light, relay coil. etc. that will
be used to give remote indication.
Caution

- 15 -
Bypass the flow of compressed air around the dryer.
The hot-gas-bypass valve can only be adjusted
accurately with no load on the dryer. Allow 15 minutes
for the dryer to stabilize before making adjustments.
Turn the adjusting screw clockwise to raise the suction
pressure. Turn counter-clockwise to lower the suction
pressure to the normal range.
Open the air bypass valve and close the block valve.
This simple adjustment does not require a trained
refrigeration technician and is not covered under
warranty.
Temperature –Pressure Chart R-22
Temperature (Deg. F) Pressure (PSIG)
28 52.4
30 54.9
32 57.5
34 60.2
35 61.5
36 62.9
38 65.7
40 68.6
45 76.1
Shutdown
The side panels of the dryer slide out to allow access for
maintenance. Keep the area directly over the dryer clear
of piping, pipe hangers, or pipe supports so that the
panels can be removed.
NOTE:It is not possible to switch the dryer between
MANUAL and AUTO modes once it is started in either
mode. To switch the dryer between modes, use the
following procedure.
1. Turn the dryer off at the “STOP” switch on the font
control panel.
2. De-energize the dryer from the main power source.
3. Toggle the MANUAL / AUTO switch to the
desired mode.
4. Re-apply the power to the dryer.
5. Turn the d
r
y
er on b
y
de
p
ressin
g
the “on” button
RDS Series — 50-1000 SCFM
Start U
p
and Shutdown Procedures
Section 5
5.0 Startup
BEFORE STARTING THIS DRYER , FOLLOW THE
INSTALLATION INSTRUCTIONS AND
PROCEDURES COMPLETELY.
SERIOUS PERSONAL INJURY CAN RESULT IF
INSTRUCTIONS ARE NOT CAREFULLY AND
COMPLETELY FOLLOWED.
DO NOT REMOVE, REPAIR, OR REPLACE ANY
ITEM ON THE DRYER WHILE THE DRYER IS
UNDER PRESSURE.
Initial Startups
(This procedure should be followed on initial startup and
after preiods of extended shutdown)
1. Confirm that all piping and electrical
connections are proper.
2. If a bypass is installed around the dryer, close the
inlet and outlet isolation valves. Open the bypass
valve.
3. With no pressure or air flow on the dryer, turn the
ON/OFF switch to AUTO. In auto, the dryer will
remain off until the pressure switch senses an
increase in pressure. In manual, the dryer will run
with no air pressure present. Dryers are shipped in
the “AUTO” mode.
4. With valves in position #2, SLOWLY pressurize
the air side of the system by opening the inlet
valve to the dryer. As pressure increases, the
dryer will turn on and begin to run.
5. When the dryer is under system pressure, slowly
open the outlet isolation valve and close the
bypass valve.
6. The system is now on line and will operate
normally. Monitor the dryer to ensure that it is
operating within the proper parameters. At rated
conditions, (100 PSI inlet pressure, 100 Deg F
inlet temperature, and 100 Deg F ambient) the
dewpoint monitor should be in the green area. As
parameters change, the dewpoint will adjust itself
accordingly.
Hot-Gas Bypass Valve Adjustment
If the suction pressure is above (or below) the normal
operating range, adjust as follows (note the suction
pressure will be high if the dryer is overloaded):

- 16 -
RDS Series —50-1000 SCFM
Maintenance and Re
p
ai
r
Section 6
Thermistors
Several functions on RDS Series refrigerated air dryers
are controlled by the main control board. Variable
resistance values from thermistors provide input signals
to the control board, which then adjusts several functions
of the dryer, based on these signals. Resistance values
can be found in the thermistor resistance value tables.
Thermistor location and function.
Inlet air thermistor - located at the inlet air port to the
dryer. Provides signal for timing of automatic drain. As air
warms up, water vapor holding capacity increases. At this
point the dryer must be able to drain more water. The inlet
thermistor will sense a rise in inlet air temperature,
causing the drain to open more frequently to allow more
drainage from the separator. Drain timing is set by jumper
position on the control board. (see drain valve timer
options table)
Dewpoint thermistor - Located on small machines (50-250
scfm) at the outlet of the evaporator. In these machines
the thermistor is not accessible because of the
construction of the evaporator assembly. The wires are
accessible at the control board terminals. In larger dryers
(300 to 1000 scfm) the thermistor is located in a well on
the control panel side of the evaporator. The dew point
thermistor senses the air temperature at the out let of the
heat exchanger. At this point the air is the coldest in the
system. At 100% RH (saturation) temperature and dew
point are the same. The signal from the thermistor is
transmitted to the control board and lights the dew point
monitor on the front of the dryer.
Condenser out thermistor - located on the liquid
refrigerant line as it leaves the condenser in the proximity
of the liquid line dryer. This thermistor senses the
temperature of the refrigerant as it leaves the condenser.
A signal is sent to the control board, which cycles the
condenser fans. In case of fan failure or poor condensing
conditions (dirty condenser, high ambient, etc.) the
temperature will continue to rise at the thermistor. At
approximately 150 Deg F the dryer will go into alarm, the
alarm light will light, and the dryer will shut down.
Compressor discharge thermistor - located on the
refrigerant discharge line of the refrigerant compressor.
This thermistor senses the temperature of the refrigerant
gas as it leaves the compressor. When the refrigerant
temperature rises indicating overload conditions to a
temperature of 245 Deg F, the liquid injection solenoid will
open. This causes liquid refrigerant to flow through a
capillary tube into the suction of the refrigerant
compressor, reducing return gas temperature to the
compressor, providing additional cooling to the
compressor. If this is not sufficient, the temperature will
continue to rise and will shut the dryer down when it
reaches 265 Deg F.
Procedure for verifying thermistor operation
1. Remove the thermistor in question from the well or
refrigerant line that it is installed on.
2. Remove the plug that contains the control wires from
CN3 on the control board.
3. Verify the thermistor terminal location by checking
the wiring diagram on the lid of the dryer.
4. With a resistance meter, measure the resistance.
Compare the reading to the value at on the table at
ambient conditions.
5. Place the probe in a bottle of ice water. Read the
resistance at 32 Deg F on the table. The values
should be close. If the resistance changes in value,
the thermistor is responding. If there is no resistance
reading, replace the thermistor.

- 17 -
Temperature Resistance
Deg. F (K ohms)
14 97
572.91
14 55.3
23 42.32
32 62.65
41 25.39
50 19.9
59 15.71
68 12.49
77 10
87 8.06
95 6.53
104 5.33
113 4.37
122 3.6
131 2.99
140 2.49
149 2.08
158 1.75
167 1.48
176 1.26
185 1.07
194 0.92
203 0.79
212 0.68
221 0.59
230 0.51
Temperature Resistance
Deg. F (K ohms)
-58 -
-40 -
-22 -
-4 -
14 -
32 163.25
50 99.5
68 62.45
86 40.29
104 26.63
122 18.02
140 12.44
158 8.76
176 6.28
194 4.58
212 3.39
230 2.55
248 1.95
266 1.51
284 1.18
302 0.93
392 0.33
482 0.14
572 0.07
RDS Series —50-1000 SCFM
Maintenance and Re
p
ai
r
Section 6
Air in, Condenser out
& Dewpoint
Thermistor Resistance Values
Discharge
Thermistor Resistance Values

- 18 -
DO NOT REMOVE, REPAIR, OR REPLACE ANY ITEM ON
THE DRYER WHILE THE DRYER IS UNDER PRESSURE.
BEFORE BEGINNING ANY REPAIRS, MAINTENANCE,
OR INSTALLATION WORK, ENSURE THAT THE POWER
IS OFF AND THE DRYER IS AT ATMOSPHERIC
PRESSURE.
BEFORE WORKING ON THE DRYER OR RELATED
EQUIPMENT, ENSURE THAT ALL PERSONNEL HAVE
READ AND UNDERSTAND THE SAFETY AND
OPERATION INSTRUCTIONS IN THIS MANUAL.
EVACUATE AND CHARGING TO BE DONE ONLY BY
A CERTIFIED EPA TECHNICIAN !
This is a suggested schedule based on average dryer
conditions. As conditions such as dirty environment,
humidity conditions, ambient temperature, etc. change,
the frequency and duration of the inspections may change.
DAILY
1. Inspect the dryer for proper operation.
2. Check the control panel for alarms.
3. Verify proper inlet and ambient air conditions.
WEEKLY
1. Test the drain by depressing the drain
switch on the main control panel.
2. Inspect and log pressure differential readings
across filters. Inspect filters if they are out of
range. Change as necessary.
MONTHLY
1. Blow entire unit out with compressed air.
2. Blow condenser coils out with compressed air.
3. Inspect refrigeration compressor for overheating.
4. Clean air filter on the condenser.
NOTE : Filters that are running in dirtier than normal
environments will need to be inspected and changed
more often.
SEMI-ANNUALLY
1. Inspect entire assembly for loose connections,
screws, panels etc.
2. Inspect refrigeration circuit for signs of oil and
refrigerant leakage.
3. Clean fan blades, casing, motors and internal
components. Use light mixture of detergent. No
oil based cleaning solvents should be used for
cleaning the unit.
A
nnuall
y
1. Tighten all electrical connections. Look for broken,
cracked, or bare wires.
2. Measure and record amperage. Verify that readings
are within acceptable parameters as listed in
specification table.
3. Clean the condenser coil with a mild detergent
mixture and brush.
1. Remove top panel from dryer.
2. Slide control panel out of the grooves in the extruded
aluminum rails. Set the panel on top of the dryer.
3. Slide the front panel out of the grooves in the
extruded aluminum rails. Set the panel aside.
4. Locate the drain solenoid valve on the lower right-
hand side of the heat exchanger assembly. Remove
the retainer screw on the top of the solenoid coil.
5. Lift the coil off of the valve and set it to the side.
6. Locate and remove the two (2) screws that hold the
valve core in place. The screws are located on either
side of the solenoid stem in the brass retainer plate.
NOTE: some of the fiberglass insulation on the heat
exchanger may need to be cleared away to gain
access to the screws.
7. Carefully remove the core from the valve assembly.
CAUTION: This assembly contains a plunger, seat,
and a small spring. Be careful to not lose any of the
small parts during di-assembly.
8. Inspect the valve seat for signs of wear. Inspect the
orifice of the valve for signs of dirt, oil, or other
contaminants. If any contaminants exist, remove
them with needle nosed pliers or a cotton swab
soaked with alcohol. Be careful not to push any
contaminants back into the valve.
9. When the valve is clean, reassemble in reverse
order.
Drain Cleaning Instructions
RDS Series —50-1000 SCFM
Maintenance and Re
p
ai
r
Section 6
Preventive Maintenance Schedule

- 19 -
Dewpoint lamp does not light Power switch is not on
Supply voltage is incorrect
Bad connection from dewpoint therrmistor
to control board
Dewpoint lamp is burned out
Depress switch on front of dryer control
panel
Verify proper voltage at inlet to dryer
Refer to wiring diagram and check proper
connections
Verify proper lamp function
Run lamp does not turn on Lamp is non functional
Air pressure is low and air pressure switch is
not made
Air pressure switch is non-functional
No supply voltage
Check lamp
Verify proper pressure at inlet of dryer –
check bypass
Check pressure switch connections at switch
and control board
Verify proper voltage
Alarm lamp is on Condenser high temperature switch is open
Compressor high temperature
switch is open
Ambient air temperature is too high
Inlet temperature to the dryer is too high
Check ambient temperature, fan motor,
condenser filter, for problems.
Check fan and high condenser temp
thermistor for proper location.
Verify liquid injection valve connections at
valve and control board.
Verify proper inlet air and ambient
conditions. Refer to specification table for
proper parameters.
See specification table for proper
parameters. Provide ventilation or means of
controlling ambient to ensure proper
conditions.
Verify proper aftercooler operation. See
specification table for proper temperature
limits.
Yellow alarm light is on
dewpoint display
Dryer is not running
No air flow through dryer or bypass is open
Inlet air temperature is too high
Air flow through dryer is too high
Dewpoint thermistor is not in
the well
Open connection from dewpoint probe to
control board
Depress on button on control panel and
verify proper operation
Close the bypass.
Open all valves.
Check for restrictions in airflow.
See previous high inlet information
See specification table for proper airflow
parameters. Adjust airflow to proper levels.
Place thermistor securely in the well
Verify proper connections at probe and
control board.
RDS Series — 50-1000 SCFM Section 7
Troubleshootin
g
Guide
Problem Possible Cause Solution

- 20 -
Problem Possible Cause Solution
Section 7
Troubleshootin
g
Guide
RDS Series — 50-1000 SCFM
Water downstream of the dryer Bypass valve is open
Drains in front of the dryer malfunctioning
Ambient air is lower than the dewpoint of the
compressed air.
Drain solenoid coil burned out
Open connection from the drain to the
control board
Drain valve is plugged
Airflow through the dryer is too high
Close bypass
Check drain for proper coil operation and
restrictions in valve. See drain cleaning
instructions.
Insulate or reroute air lines in problem areas.
Ohm coil and verify proper operation.
Replace if necessary.
Verify proper connections at the coil and the
control board
See drain cleaning instructions
See previous air flow instructions
Large pressure drop across the dryer Inlet or outlet valves are closed
Dirty or plugged filters in air system
Frozen heat exchanger
Plugged heat exchanger
Airflow through the dryer is too high
Open valves and verify proper positions.
Check filters, Change if necessary
Adjust airflow to appropriate levels.
Adjust hot gas valve. See HGV
adjustment instructions.
Verify that exchanger is plugged. Clean
as necessary
See previous air flow instructions
Alarm lamp is on and dryer is not
running
Condenser high temperature safety is tripped
Compressor high temperature safety is
tripped
Clear conditions that caused alarm.
Remove and restore power to dryer
to reset.
Clear conditions that caused alarm.
Remove and restore power to dryer
to reset.
Alarm lamp and run lamp off and dryer
will not run
Disconnect switch or breaker is off
Voltage is out of range
Control fuse is blown
Restore power
Verify proper voltage
Verify and correct cause of problem.
Replace fuse.