Gardner Denver Thomas 2660AT32-492W Quick start guide

Field Service Manual
FOR MODEL NUMBER
2660AT32-492W
©2006 Gardner Denver Thomas, Inc. FSM 0182 04/06

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A Field Service Manual
Prepared by:
Table of Contents
Page
Introduction ..................... 4
Safety First ...................... 5
Exploded View and Parts List ......................................................................................................................... 6
Wiring Diagram ................ 8
Preventive Maintenance and Troubleshooting Guide ....................................................................................... 9
Required Tools and Materials ....................................................................................................................... 11
Component Repair ....... 12
Servicing the Valve Assembly ................................................................................................................. 13
Rebuilding the Connecting Rod Assembly .......................................................................................... 17
Replacing the Connecting Rod and Eccentric Assembly ........................................................................ 18
Assembly of the Compressor ................................................................................................................ 20
Field Service Manual
for model number
2660AT32-492W
©2006 Gardner Denver Thomas, Inc.
Field Service Manual
FSM 0182 04/06

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Introduction
This Field Service Manual is intended for use ONLY by properly trained and experienced repair personnel employed
by an authorized service center. THIS SERVICE MANUAL SHOULD NOT BE USED BY OR DISTRIBUTED TO
THE PUBLIC. THE INSTRUCTIONS AND WARNINGS HEREIN PRESUME EXISTING FAMILIARITY WITH THE
DESIGN AND FUNCTION OF THESE AND SIMILAR PRODUCTS, AND THEIR COMPONENTS.
Please Note:
The model(s) represented in this manual may have additions and/or modifications made at any time. Pictures
represent a standard unit series and an actual unit may vary slightly. This manual is based on the latest technical
information available at the time of creation or last revision. It is believed to be generally accurate and reliable.
Consult the factory if additional detailed information is desired, or whenever there is a question about a given unit’s
configuration or performance specifications.

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Safety First
It is recommended that you thoroughly read and understand this manual before you attempt to
service the Thomas series of compressors to which this applies. PLEASE NOTE THE FOLLOW-
ING CAUTIONS AND WARNINGS FOR YOUR OWN SAFETY.
CAUTION
To avoid personal injury and/or property damage, only authorized service personnel should
service this unit.
WARNING
To avoid the risk of electrical shock, personal injury, or death, disconnect power before
servicing this unit.
CAUTION
To avoid personal injury, do not remove fan guards while unit is connected to power.
CAUTION
To avoid personal injury, especially to eyes and face, use eye and face protection when
servicing this unit.
CAUTION
To avoid personal injury, especially to eyes and face, never point the exhaust air flow at
yourself or other people in the area. Unit is capable of pressures of very high pressures.
CAUTION
To avoid damage, never lubricate any component in your compressor. All moving parts
are permanently lubricated.
CAUTION
To avoid property damage or personal injury, always try rotating the fan by HAND prior to
connecting the unit to the power source. Check for suction at the air inlet port by placing
your finger over the port as you turn the fan. You should feel a slight suction with each
rotation of the fan. If you don't feel suction, or if you feel or hear a thump as you turn the
fan, DO NOT CONNECT THE UNIT TO A POWER SOURCE. Review the assembly
procedure for possible error.

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Exploded View and Parts List
Exploded View of the Thomas 2660AT32/492W

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Field Service Parts List for Thomas 2660AT32/492W
Item
No.
Part No. Qty. Per
Assembly
Qty. Per
Unit
Description
1 640109 -- 2 Connecting Rod, Eccentric & Bearing Ass'y
2 624680W 1 2 Piston Cup
3 625776 1 2 Screw - Piston Cup Retainer
4 626392 1 2 Piston Cup Retainer
5 618114 1 2 Cylinder Sleeve
6 610534 -- 1 Head
7 623143 -- 2 O-Ring - Head Gasket
8 625175 -- 8 Screw - Head
9 621591 -- 2 Valve Plate Assembly
10 617177 1 2 Valve Restraint
11 617562 2 4 Valve Keeper Strip
12 621485 2 4 Valve Flapper - Intake & Exhaust
13 621641 1 2 Valve Plate
14 625094 2 4 Screw - Valve Flapper
15 623137 -- 2 O-Ring Valve Plate
16 638281 -- 1 Fan - Gray
17 638282 -- 1 Fan - Black

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Use this wiring diagram to connect your
compressor to the power source.
Wiring Diagram
2660AT32-492W
LINE
LINE
CAPACITOR
BLUE
RED
BROWN
RED

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Thomas Products Group recommends that you perform the following service to minimize
unexpected downtime for your compressor:
• Replace the connecting rods or piston cups and sleeves
• Replace the flapper valves
• Replace the head gasket O-rings
• Replace the valve plate O-rings
Preventive Maintenance and Troubleshooting Guide

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Troubleshooting Guide
If you are having a problem with your compressor, use this table to help determine the cause(s):
Problem Possible Cause Corrective Action
Low
Flow
Low
Pressure
Unit Will
Not Start
Motor
Overheats
Loud
Unit
xHigh voltage at
compressor Reduce voltage
x x x x Low voltage at
compressor Increase voltage
x x x Damaged valves Replace flapper valves
x x x Debris in valves Remove debris and
check for valve damage
x x x Damaged gaskets Replace gaskets
x x x Worn Cup Replace connecting rod
assembly or cup
x x x Loose head screws Tighten head screws
x Broken fan Replace fan
x x x Bent motor shaft Replace entire unit
x x Damaged capacitor Replace capacitor
x Loose fittings Tighten fittings
x x Insufficient ventilation
in enclosure
Increase air circulation
to enclosure
x x Worn bearings Replace eccentric and
bearing assembley
1 Thermal protector in motor will interrupt current when motor overheats.

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Required Tools and Materials
To disassemble and reassemble your compressor, you need the following tools and materials:
 Torque wrench that has an inch-pound scale (for head screws, set screws, flapper valve screw, and
pipe plugs).
 Torx® T-25 driver (for head screws).
 5/32" Allen wrench attachment for torque wrench (for eccentric set screw).
 1/4" Hex Socket attachment for torque wrench (for flapper valve screw).
 Torx® T-27 driver (for retainer screws).
 Soft, clean cloths
Compressor
Housing
Power LEAD END
Reference Drawing: Terminology to assist with the following instructions.
Power LEAD SIDE
of Compressor

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Component Repair
Servicing the Head, Valve Plate
Assembly and Connecting Rod and
Bearing Assembly
The head would only need to be replaced if it is
visibly damaged.
Component Parts Required
You will need:
 Head (if damaged)
 Head gasket O-ring
 Valve plate O-ring
 Complete valve plate assembly or individual
flapper valves.
 Flapper valve screw(s) if replacing individual
flapper valve(s).
Removing the Head
1. Disconnect the power.
2. Disconnect all air lines and remove
compressor from the enclosure.
3. Remove all screws (1) that fasten the head
(2) to the compressor housing.
4. Carefully separate the head from the
compressor body.
5. Carefully separate the valve plate
assemblies (4) from the heads.
6. Remove the head gasket O-rings (3) and
replace.
7. Turn the valve plates over and replace the
valve plate gasket O-rings (5).
Attention
If you are replacing the head and
gaskets only, see the assembly
instructions on page 20. To replace
the valve flappers and connecting rod
assembly, continue to page 13.
1
2
3
4
5

13
1
2
3 4
Opposite Lead Side
1
2
Port 1
Removing the Flapper Valves
Note: We recommend you remove and replace
one flapper valve at a time. This will help to
simplify the repair process and orient the
flapper valve correctly on the valve plate.
1. If you are replacing a flapper valve on the top
side of the valve plate (side facing the head),
remove the flapper valve screw (1) with a 1/4"
hex socket, lift off the valve keeper strip (2), lift
off the valve restraint (3), and lift off the flapper
valve (4).
2. Remove any debris from the valve plate with
a damp, lint free cloth. (Soaps and detergeants
should not be used due to the potential for
corrosion from soap residue.)
3. Place the valve plate on the compressor housing
and orient it as illustrated. Note the orientation
of the valve ports.
4. Orient a new flapper valve (1) over Port 1.
Observe the location of the notches (2) at the
end of the flapper valve.2. Orient a flapper
valve (1) over Port 1. Observe the location of
the notches (2) at the end of the flapper valve 2.
Orient a flapper valve (1) over Port 1. Observe
the location of the notches (2) at the end of the
flapper valve.
Tab indicates
exhaust side

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5. Place a valve restraint (3) over the flapper
valve.
6. Place a valve keeper strip (4) over the valve
restraint observing that the word “UP” is
facing you and oriented as shown in the
illustration.
7. Line up the screw holes in all of the valve
components and insert the flapper valve
screw (5) into the valve plate.
8. Make sure the flapper valve is centered
over the port and that all of the other
components line up with the flapper valve.
Caution
Do not overtighten the flapper valve
screw or it will shear off in the valve
plate.
9. Tighten the flapper valve screw to 18 inch-
pounds, using a torque wrench with a 1/4"
hex socket attachment.
3
4
5

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Lead Side
1. If you are replacing a flapper valve on the
bottom side of the valve plate (side facing the
compressor housing), remove the flapper valve
screw (1) with a 1/4" hex socket, lift off the
valve keeper strip (2), and lift off the flapper
valve (3).
1
2
3
Port 1
Port 2
2. Clean any debris with a soft, damp cloth. Turn
the compressor head upside down and place
the valve plate on the compressor head and
orient it as illustrated. Note the position of the
valve ports and the location of the power leads
on the compressor housing.
3. Orient a flapper valve (1) over Port 2. Observe
the location of the notches (2) at the end of the
flapper valve.
Lead Side
2
1
Tab indicates
exhaust side

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4. Place a valve keeper strip (3) over the
flapper valve, observing that the word
“UP” is facing you, not the valve plate, and
oriented as shown in the illustration.
5. Line up the screw holes in all of the valve
components and insert the flapper valve
screw (4) into the valve plate.
6. Make sure the flapper valve is centered over
the Port and that the valve keeper strip lines
up with the flapper valve.
Caution
Do not overtighten the flapper valve
screw or it will shear off in the valve plate.
7. Tighten the flapper valve screw to 18 inch-
pounds, using a torque wrench with a 1/4"
hex socket attachment.
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Attention
If you are only replacing the valve
flappers, see the assembly instructions
on page 20.
If you are replacing the cup and sleeve
turn to the Rebuilding Connecting Rod
Assemblies Section found on page
17.

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Servicing the Connecting Rod Assembly
and Eccentric Assembly
Refer to the Preventive Maintenance and
Troubleshooting Guide in this manual to determine
whether a complete connecting rod assembly, or
its component parts, or an eccentric needs to be
serviced.
Component Parts Required
You will need:
 Connecting rod assembly(ies) or piston cups
and sleeves
 Valve plate gasket O-ring(s)
 Head gasket O-ring(s) (if defective)
Removing the Connecting Rod Assembly and
Eccentric
NOTE: ONLY REMOVE ONE CONNECTING ROD
ASSEMBLY AT A TIME.
1. Carefully remove the fan by pulling it straight off
the motor shaft. Do not pull the fan blades.
2. Turn the motor shaft to align the eccentric set
screw with its access hole and use an Allen
wrench to loosen the eccentric set screw (see
illustration for location of access hole).
Eccentric
Set Screw
Eccentric Set Screw
Access Hole

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Caution
Do not crimp the piston cup (4)
when you remove the connecting
rod assembly from the compressor
housing. If the cup is crimped, you
must replace it.
3. Make sure the connecting rod is at "Top
Dead Center". Slide the connecting rod
assembly straight off the shaft through the
opening in the housing.
Opening in
Housing
Rebuilding Connecting Rod Assemblies
If you are rebuilding the connecting rod assembly
using component parts, follow this procedure:
When replacing the piston cup (4), be sure to
replace the sleeve (1) at the same time. Place
the con rod shaft in a fixture before attempting
to remove the retainer screw. Heat will help
to dissolve the loctite bond.
1. Remove the retainer screw (2) from the cup
retainer.
2. Remove the retainer (3) from the connecting
rod.
3. Remove the cup (4) and discard.
4. Place the new piston cup (4) on the connecting
rod.
5. Place a piston cup retainer (3) on the
cup/connecting rod making sure the boss of
the retainer is seated in the pilot of the rod.
6. Insert the retainer screw (2) into the connecting
rod (5) and tighten to 95-105 inch-pounds.
Attention
To replace the connecting rod and
bearing assembly turn to page 19. Note:
Both Connecting Rods shown for orientation, DO
NOT remove both at once.
1
2
3
4
51
2
3
4
5

19
Note: Both connecting rod assemblies shown
for orientation. DO NOT remove both at once.
Assembly of the Connecting Rod to the
Compressor
1. Line up eccentric set screw with flat on shaft.
Slide connecting rod assembly over shaft
through front of housing with eccentric toward
end of shaft. Push connecting rod assembly
tight against housing bearing.
2. Rotate eccentric to line up set screw with
access hole in bottom of housing. Tighten
screw to 125 in. lbs. Make sure the eccentric
set screw is seated perpindicular on the shaft
flat.
Set Screw
Access Hole

20
Reassembling the Compressor
After the connecting rod assembly and eccentric
are correctly assembled, you can assemble the
valve plates and head to the compressor.
Caution
To prevent damage to the compressor,
never apply any sealant or lubrication
to the O-rings.
1. Insert a new head gasket O-ring into the groove
located on the top of the valve plate.
2. Insert the valve plate gasket O-ring into the
O-ring groove located on the bottom of the
valve plate.
O-ring Gasket
Groove
O-ring Groove
O-Ring
Bottom of Valve Plate
Top of Valve Plate