Joy TWISTAIR TA-020 Installation and maintenance instructions

OPERATOR’S MANUAL
and PARTS LIST
JOY”
TWISTAIR”
SCREW COMPRESSOR
MODELS
TA-020
TA-025
MC-2224
FORM NO. MC-2224

Joy Twistair@
Screw Compressor
\#gffW
OPERATOR’S MANUAL
AND
PARTS BOOK
20 and 25 HORSEPOWER
JOY MANUFACTURING COMPANY
AIR POWER DIVISION
Michigan City, Indiana 46360
PRICE $7.50
FoRM MC-2224 4-73 A/l PRINTED IN U.S.A.

JOY TWISTAIR SCREW COMPRESSOR
*
‘#w
FRONT VIEW

TABLE OF CONTENTS
General Description
Installation ,. ., ,,
Location ,,,
Electrical Connections ,.
Air Supply .,, ,,
Wiring Diagram ,. ...
Piping ... .,. ,,
Lubrication ,,. ,., ... .,,,, ,,,
Compressor Oil Specifications
Lubrication System ,.
Oil-Air Flow Schematic
Oil Sump ., .,.
Controls ,. .,.
Control Selection ... .,
Method of Control Operation
Drive
Compressor Operation ., ,.
Preparation for Initial Start-Up
Emergency Shut-Down .,
Restart after Power Failure ,... ,,. ,.
Periodic Maintenance Schedule ., ,.
Initial Oil Change ..........................................................
Cleaning Air Filter Element .................... . . ... .
Replacing Oil-Air Separator Element ................................. .. .
Replacing Oil Filter Element ,... . . . .,
Installing Oil Seal . ............... .......... ....,,,, ,.,,....,,,,.,,, ...,,,
Pressure Switch Adjustment ........................................... ..... .... .. . .
Testing High Air Temperature Switch ......... . . . .. . ...... .. .....
Trouble Shooting ............. ..... ........ .,......
Safety Precautions . .. . ............. . .
Parts Listirw ..- ~~~~~~~~~~~~-~~~~~~~~~~~~~~~~~~
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3
4
4
4
5
6
7
7
7
8
9
10
10
10
12
14
14
15
15
16
16
17
17
18
18
18
19
19
21
22
Compressor ‘Accessories ,., .......... ............ ....... ...... ........48-53
War;anty ... ... ..... . .. ... ............. . ............. .... .. 54
1

OPERATOR’S MANUAL
JOY
TWISTAIR COMPRESSOR
GENERAL DESCRIPTION
FIGURE 166-51
Housing (Stator)
The Joy Twistair Compres-
sor is apositive displacement,
flood lubricated, screw type
compressor that employs a
single stage of compression to
achieve the specified pressure
and capacity. The compressor
consists of ahousing (stator)
figure 1, two screws (rotors)
figure 2, bearings, bearing
housing and end covers. In
operation the male rotor, 1
figure 2, turns at its rated
speed, however, the female ro-
tor, 2figure 2, turns at only
two-thirds the speed of the
speed of the male rotor. This is
because the male rotor has 4lobes
while the female has 6.
Compression is obtained by
trapping air between the threads
or lobes of the iwo rotors. As the
rotors turn, the lobes mesh, reduc-
ing the volume in the pockets and
thus compressing the trapped air.
The compressed air is discharged
through the discharge port just as
it reaches discharge pressure.
The principle of screw type
compression is illustrated in fig-
ure 3.
FIGURE 266-52
Screws (Rotors)
1. Male. Rotor 2. Female Rotor
2

FIGURE 366-ss
Principle of Operation of Screw Typo Compressor
The Joy Twistair Compressors covered in this manual are rated
at 20 and’25 Horsepower. Other models of the Joy Twistair Com-
pressors are available in sizes ranging from 71A horsepower Up
through 300 horsepower.
The Twistair Compressors in this manual have capacities of
77.4 CFM for the 20 Horsepower unit and 95.2 CFM for the 25
Horsepower unit, and are rated at 100 PSIG service discharge pres-
sure. They are designed to deliver amaximum of 125 PSIG, and
are available either as base mounted or tank mounted units. The
tank mounted unit is mounted on a 120 gallon tank. Oversize tanks
are available as ol)tional equipment, refer to accessory section of
this manual for a;ailable sizes.
INSTALLATION
SAFETY vALVE
CAUTION: OblBASEMCUNTED UNITS NEVER INSTALL ASHUT+FF
VALVE IN THE LINE BETWEEN COMPRESSOR AND RECEIVER WITHOIJT ~
APOPSAFETY VALVEON THE COMME5S0R SIDE,
SHUT-OFF
vALVE
~/
i
I
E
FIGURE 46S-16
Typical installation
3

LOCATION
The Joy Twistair compressor is designed for indoor operation
in ambient temperature ranging from 50° F. to 105° F. In selecting
the location for the compressor it is important that there is an
ample supply of well circulated air. Do not set the unit with
the, oil cooler side closer than 12 inches from awall or other ob-
struction which would restrict the free flow of air through the
cooler. Agood circulation of air through the cooler is important.
In order to avoid excessive pressure loss through use of extended
pipe or hose lines, the compressor should be located as close as
possible to the point where the air is to be used.
CAUTION
IF CONTAMINATED AIR CONTAINING ACID,
PAINT OR CORROSIVE MATTER IS PRESENT,
THEN AN OUTSIDE SOURCE OF AIR MUST BE
PROVIDED FOR THE COMPRESSOR AIR INTAKE.
ELECTRICAL CONNECTIONS
Have electrical connections to the power source made by acom-
petent electrician in accordance with local codes. It is extremely
important that the wiring is accomplished to assure proper rotation
of the compressor as indicated by the direction of rotation arrow
on the discharge and bearing cap.
The electrical circuit must have the same characteristics and
voltage as indicated on the motor nameplate and as is called for in
the controllers and wiring diagram. See figure 5, Page 5.
UNIT MUST BE GROUNDED. Ground from ground connec-
tion on base to agood ground connection. Use #8 wire or larger.
AIR SUPPLY
Aclean air supply is desirable for the satisfactory operation of
your Joy Compressor. Intake air temperature should range from 50°
F. to 105° F. Where alternate sources of intake air are available,
select the source supplying the cleanest air. The standard air filter
with which the compressor is equipped is of sufficient size and
design to meet all normal operating conditions if serviced regularly,
in accordance with the service schedule given on Page 16.
NOTE
IF THE COMPRESSOR IS TO OPERATE IN AN AREA
WHERE CONSIDERABLE LINT, DUST, DIRT OR
4

-WIRING DIAGRAM WD -10913-
w
LI L2 L3
ICR 2CR
&M =kM &M
‘?” ‘$” ‘$’3
WHEN USING TRANSFORMER
CONNECT AS FOLLOWS:
VOLTAGE TERMINALS TRANSFORMER
20U HI -H2 SPECIAL
230 HI -H2 JOY SUPPLIED
460 HI -H3 JOY SUPPLIED
575 HI -H4 JOY SUPPLIED
NOMENCLATURE:
CR —CONTROL RELAY
APS—AIR PRESSURE SWITCH
ATS— HIGH AIR TEMPERATURE SWITCH
Isv —SOLENOID VALVE (UNLOADER)
2SV—SOLENOID VALVE (OIL STOP)
FU —FUSE
OL —OVERLOAD RELAY
Ss —SELECTOR SWITCH
M—MOTOR STARTER
I
COMPRESSOR MOTOR
TERMINALS
@-TB @-STARTER
xl
~CONTROL TRANSFORMER OR< LISTOMER’S 115VA SUPPLY —I
,----- —-—— —___ ____ ____
tCONTROI TRANSFORMER (WHEN ORDERED) 7
xl II
Ix3
Il! 0
I
I I
IH3
I
I
tL) I
l– —-–--0-—--—-- –_-___ :-–_J
STOP
ICR 4
4b4ib :CONST, 712
I511
APS *:.
x3
k}
M9Isv
FIGURE 5
Wiring Diagram 5

OTHER CONTAMINATES ARE PRESENT, IT IS SUG-
GESTED THAT AN AIR FILTER RECOMMENDED
FOR THE SPECIFIC ENVIRONMENT BE SUBSTI-
TUTED FOR THE STANDARD FILTER. AN ALTER-
NATE TO THE SPECIAL FILTER WOULD BE A
MORE FREQUENT MAINTENANCE SCHEDULE FOR
THE STANDARD FILTER. THE FREQUENCY FOR
THE MAINTENANCE OF THE STANDARD FILTER
MAY HAVE TO BE ESTABLISHED AFTER APER-
IOD OF USAGE.
PIPING FOR OUTSIDE SOURCE OF AIR
When an outside source of air is to be supplied, the following
rules
1.
2.
3.
4.
5.
6.
7.
8.
should be followed:
Protect intake from the weather, rain and snow.
Keep intake pipe away from steam, gas, or engine exhaust.
Vapors will be drawn into the compressor whether there is a
filter or not.
Take outside air from at least 6feet above ground or roof
level. This is to minimize picking up dirt and litter in the
intake.
If possible, locate the intake on the shady (usually north)
side of the building and, if possible, under an overhang, as
the air is cooler in these locations.
Install the intake pipe from the compressor outward. Make
the pipe the same size or larger than the compressor intake
opening. As arule of thumb, increase the pipe diameter 2
inches for every 15 feet of piping.
Support intake lines with hangers, clamps and floor columns
to keep weight of lines off compressor.
Intake piping should include asection of hose or flexible
tubing.
Interior of added inlet piping must be corrosion resistant.
DISCHARGE PIPING
As previously stated, the compressor should be located as closely
as possible to the point of compressed air usage. However, whatever
piping is used in the distribution system should be constructed to
offer aminimum amount of resistance to air flow between the
receiver and point of use. Long radius elbows and pipe of sufficient
size should be used. In no case should the piping be of smaller size
than the receiver discharge opening. ,
NOTE
IN CASES WHERE THE COMPRESSOR IS CONNECT-
ED IN THE SAME LINE AS ARECIPROCATING
COMPRESSOR, ASURGE VOLUME CHAMBER AND
ACHECK VALVE MUST BE INSTALLED IN THE
AIR LINE BETWEEN THE TWO COMPRESSORS.
6

THE CHECK VALVE SHOULD BE LOCATED BE.
TWEEN COMPRESSOR DISCHARGE AND SURGE
CHAMBER. THIS APPLIES ONLY TO BASE MOUNT-
ED UNITS. ON TANK MOUNTED UNITS THE RE-
CEIVER ACTS AS ASURGE CHAMBER.
LUBRICATION
The operating principle of the compressor is such that the pres-
sure circulated oil in the system serves three purposes:
1. Lubricates the rotating parts and bearings.
2. Serves as cooling agent for the compressed air to maintain
the discharge air temperature within 100° F. of ambient
temperature provided it is properly maintained.
3. Assures high efficiency and maximum air delivery by helping
to seal the running clearance in the screws.
COMPRESSOR OIL SPECIFICATIONS
Joy Twistair compressors under normal operating conditions
can use either a 10 weight premium heavy-duty motor oil or 10
weigth premium quality heavy-duty industrial type oil. However
under extremely humid operating conditions the 10 weight heavy-
duty industrial type oil is the preferred choice.
Viscosity of the oil should be 160 to 210 SSU at 100” F. and the
oil should contain rust and oxidation inhibitors and foam suppres-
sors. The flash point of the oil must be 4000F. minimum.
CAUTION
IF DIFFERENT BRANDS AND TYPES OF OIL ARE
MIXED THERE IS ADISTINCT POSSIBILITY THAT
SOME OF THE ADDITIVES OF ONE BRAND WILL
REACT WITH THE ADDITIVES OF THE OTHER
BRAND. FOR THIS REASON THE MIXING OF DIF-
FERENT BRANDS OF OIL MUST BE AVOIDED.
LUBRICATION SYSTEM
Cooled oil under pressure is directed from the oil cooler to the
compressor, where it serves as alubricant, cooling agent and seal.
As it passes through the compressor it mixes with the air being
compressed and discharges with the compressed air into the oil
sump, where nearly all the oil in the air drops out due to imping-
ement and velocity change. Most of the remaining additional traces
of oil are removed as the air passes through the special oil separ-
ator device. The oil thus separated returns to the sump, and the air
leaves the sump at the discharge opening. The hot filtered oil from
the sump returns through the air-cooled oil cooler for re-circulation
through the compressor completing the cycle.
The oil-air flow schematic figure 6, illustrates the circulation
of air and oil in the system,
7