Sullair 20/12 Series User manual

20/12 SERIES - 2 STAGE
OPERATOR’S
MANUAL
Part Number 250041-546
ESullair Corporation, 1993
Effective 5/93
AIR COMPRESSOR
INDUSTRIAL
500 - 750 CFM
AIR-COOLED AND WATER COOLED

AIR CARE
SEMINAR TRAINING
SullairAirCareSeminarsare3-daycoursesthatprovidehands-oninstructionin
the proper operation, maintenance and service of Sullair equipment. Individual
seminars on Industrial compressors and compressor electrical systems are
presentedatregular intervalsthroughout theyear atadedicatedtrainingfacility
at Sullair’s corporate headquarters in Michigan City, Indiana.
Instruction includes discussion of the function and installation of Sullair service
parts, troubleshooting of the most common problems, and actual equipment
operation. The seminars are recommended for maintenance and service
personnel.
For detailed course outlines, schedule and cost information contact:
Sullair Corporate Training Department
1-800-348-2722 or 219-879-5451 (ext. 1867)
-OrWrite-
Sullair Corporation
3700 E. Michigan Blvd.
Michigan City, IN 46360
Attn: Service Training Department

TABLE OF CONTENTS
Section 1
SAFETY 11.1 GENERAL
11.2 PERSONAL PROTECTIVE EQUIPMENT
11.3 PRESSURE RELEASE
21.4 FIRE AND EXPLOSION
21.5 MOVING PARTS
21.6 HOT SURFACES, SHARP EDGES AND SHARP CORNERS
21.7 TOXIC AND IRRITATING SUBSTANCES
31.8 ELECTRICAL SHOCK
31.9 LIFTING
41.10 ENTRAPMENT
Section 2
DESCRIPTION 52.1 INTRODUCTION
52.2 DESCRIPTION OF COMPONENTS
62.3 SULLAIR COMPRESSOR UNIT,
FUNCTIONAL DESCRIPTION
72.4 COMPRESSOR COOLING AND LUBRICATION
SYSTEM, FUNCTIONAL DESCRIPTION
82.5 COMPRESSOR DISCHARGE SYSTEM,
FUNCTIONAL DESCRIPTION
10 2.6 CAPACITY CONTROL SYSTEM,
FUNCTIONAL DESCRIPTION
12 2.7 AIR INLET SYSTEM, FUNCTIONAL DESCRIPTION
12 2.8 INSTRUMENT PANEL GROUP,
FUNCTIONAL DESCRIPTION
Section 3
SPECIFICATIONS 13 3.1 TABLE OF SPECIFICATIONS
13 3.2 LUBRICATION GUIDE
Section 4
INSTALLATION 14 4.1 MOUNTING OF COMPRESSOR
14 4.2 SERVICE AIR PIPING
14 4.3 COUPLING ALIGNMENT CHECK
14 4.4 FLUID LEVEL CHECK
14 4.5 MOTOR ROTATION DIRECTION CHECK
14 4.6 ELECTRICAL PREPARATION

TABLE OF CONTENTS
(CONTINUED)
Section 5
OPERATION 15 5.1 GENERAL
15 5.2 PURPOSE OF CONTROLS
17 5.3 INITIAL START-UP PROCEDURE
17 5.4 SUBSEQUENT START-UP PROCEDURE
17 5.5 SHUTDOWN PROCEDURE
Section 6
MAINTENANCE 18 6.1 GENERAL
18 6.2 DAILY OPERATION
18 6.3 MAINTENANCE AFTER INITIAL 50 HOURS
OF OPERATION
18 6.4 MAINTENANCE AS REQUIRED BY
LUBRICATION GUIDE (SECTION 3)
18 6.5 FILTER MAINTENANCE
18 6.6 PARTS REPLACEMENT AND ADJUSTMENT
PROCEDURES
27 6.7 MOTOR CONNECTION INSTRUCTIONS
27 6.8 TROUBLESHOOTING
Section 7
RECOMMENDED
SPARE PARTS 31 7.1 PROCEDURE FOR ORDERING PARTS
31 7.2 RECOMMENDED SPARE PARTS LIST

Section 1
SAFETY
1
1.1 GENERAL
Sullair Corporation and its subsidiaries design and
manufacture all of their products so they can be op-
erated safely. However, the responsibility for safe
operation rests with those who use and maintain
these products. The following safety precautions
are offered as a guide which, if conscientiously fol-
lowed, will minimize the possibility of accidents
throughout the useful life of this equipment.
The compressor should be operated only by those
who have been trained and delegated to do so, and
whohavereadandunderstoodthisOperator’sMan-
ual. Failure to follow the instructions, procedures
and safety precautions in this manual may result in
property damage, accidents and injuries.
NEVER start the compressor unless it is safe to do
so.DONOT attempttooperatethecompressorwith
a known unsafe condition. Tag the compressor and
render it inoperative by disconnecting and locking
out all power at source or otherwise disabling its
primemoversootherswhomaynot knowof the un-
safe condition cannot attempt to operate it until the
condition is corrected.
Install, use and operate the compressor only in full
compliance with all pertinent OSHA regulations and
allapplicableFederal, State, andLocal codes, stan-
dards and regulations.
DO NOT modify the compressor and/or controls in
any way except with written factory approval.
While not specifically applicable to all types of com-
pressors with all types of prime movers, most of the
precautionary statements contained herein are ap-
plicable to most compressors and the concepts be-
hindthesestatementsaregenerally applicabletoall
compressors.
1.2 PERSONAL PROTECTIVE EQUIPMENT
Prior to installing or operatingthe compressor, own-
ers, employers, and users should become familiar
with, and comply with, all applicable OSHA regula-
tions and any applicable Federal, State and Local
codes, standards, and regulations relative to per-
sonal protective equipment, such as eye and face
protective equipment, respiratory protective equip-
ment, equipment intended to protect the extremi-
ties,protectiveclothing,protectiveshieldsandbarri-
ers and electrical protective equipment, as well as
noise exposure administrative and/or engineering
controls and/or personal hearing protective equip-
ment.
1.3 PRESSURE RELEASE
A. Open the pressure relief valve at least weekly to
make sure it is not blocked, closed, obstructed or
otherwise disabled.
B. Install an appropriate flow-limiting valvebetween
theserviceairoutletandtheshut-off (throttle)valve,
either at the compressor or at any other point along
the air line, when an air hose exceeding !@2”
(13mm) inside diameter is to be connected to the
shut-off (throttle) valve, to reduce pressure in case
of hose failure, per OSHA Standard 29 CFR
1926.302(b)(7).
C. Whenthehoseistobeusedtosupplyamanifold,
install an additional appropriate flow-limiting valve
between the manifold and each air hose exceeding
!@2” (13mm) inside diameter that is to be con-
nected to the manifold to reduce pressure in case of
hose failure.
D. Provide an appropriate flow-limiting valve at the
beginningof eachadditional75feet (23m)of hosein
runs of air hose exceeding !@2”(13mm) inside di-
ameter to reduce pressure in case of hose failure.
E. Flow-limiting valves are listed by pipe size and
rated CFM. Select appropriate valves accordingly,
inaccordancewiththeir manufacturer’srecommen-
dations.
F. DO NOT use air tools that are rated below the
maximum rating of the compressor. Select airtools,
air hoses, pipes, valves, filters andother fittings ac-
cordingly. DO NOT exceed manufacturer’s rated
safe operating pressures for these items.
G. Secure all hose connections by wire, chain or
other suitable retaining devices to prevent tools or
hose ends from being accidentally disconnected
and expelled.
H. Openfluidfiltercaponlywhencompressor isnot
running and is not pressurized. Shut down the
compressor and bleed the sump (receiver) to zero
internal pressure before removing the cap.
I. Vent allinternalpressureprior toopeninganyline,
fitting, hose, valve, drain plug, connection or other
components, such as filters and line oilers, and be-
fore attempting to refill optional air line anti-icer sys-
tems with antifreeze compound.
J. Keeppersonneloutoflinewithandawayfromthe
discharge opening of hoses or tools or other points
of compressed air discharge.
K.Useairatpressureslessthan30psig(2.1bar)for
cleaning purposes, and then only with effective chip
guarding and personal protective equipment per
OSHA Standard 29 CFR 1910.242 (b).
L. DO NOT engage in horseplay with air hoses as
death or serious injury may result.
M. This equipment is supplied with an ASME de-
signedpressurevesselprotectedbyanASMErated
relief valve. Lift the handle once a week to make
sure the valve is functional. DO NOT lift the handle
while machine is under pressure.
N. If themachine is installed inan enclosed area it is
necessary to vent the relief valve to the outside of
the structure or to an area of non-exposure.

Section 1
SAFETY
2
1.4 FIRE AND EXPLOSION
A. Clean up spills of lubricant or other combustible
substances immediately, if such spills occur.
B.Shutoffthecompressorandallowittocool. Then
keep sparks, flames and other sources of ignition
away and DO NOT permit smoking in the vicinity
when checking or adding lubricant or when refilling
air line anti-icer systems with antifreeze compound.
C. DO NOT permit fluids, including air line anti-icer
system antifreeze compound or fluid film, to accu-
mulate on, under, or around acoustical material, or
onanyexternalsurfacesof theaircompressororon
internalsurfaces of the enclosure. Wipe down using
an aqueous industrial cleaner or steam clean as re-
quired. If necessary, remove acoustical material,
cleanallsurfacesandthenreplaceacousticalmate-
rial. Any acoustical material with a protective cover-
ing that has been torn or punctured should be re-
placed immediately to prevent accumulation of liq-
uids or fluid film within the material.DONOTuse
flammable solvents for cleaning purposes.
D. Disconnect and lock out all power at source prior
to attempting any repairs or cleaning of the com-
pressor or of the inside of the enclosure, if any.
E. Keep electrical wiring, including all terminals and
pressureconnectorsingoodcondition.Replaceany
wiring that has cracked, cut, abraded or otherwise
degraded insulation or terminals that are worn, dis-
colored or corroded. Keep all terminals and pres-
sure connectors clean and tight.
F. Keep grounded and/or conductive objects such
as tools away from exposed live electrical parts
such as terminals to avoid arcing which might serve
as a source of ignition.
G.Removeanyacousticalmaterialorothermaterial
that may be damaged by heat or that may support
combustion and is in close proximity, prior to at-
tempting weld repairs.
H. Keep suitable fully charged Class BC or ABC fire
extinguisherorextinguishersnearbywhenservicing
and operating the compressor.
I. Keep oily rags, trash, leaves, litter or other com-
bustibles out of and away from the compressor.
J. DO NOT operate the compressor without proper
flowof cooling airorwateror with inadequateflowof
lubricant or with degraded lubricant.
K. DO NOT attempt to operate the compressor in
any classification of hazardous environment unless
the compressor has been specially designed and
manufactured for that duty.
1.5 MOVING PARTS
A. Keep hands, arms and other parts of the body
and also clothing away from couplings, fans and
other moving parts.
B. DO NOT attempt to operatethe compressor with
the fan, coupling or other guards removed.
C. Wear snug fitting clothing and confine long hair
when working around this compressor, especially
when exposed to hot or moving parts.
D. Keep access doors, if any, closed except when
making repairs or adjustments.
E. Make sure all personnel are out of and/or clear of
the compressor prior to attempting to start or oper-
ate it.
F. Disconnect and lock out all power at source and
verifyat thecompressorthat allcircuitsarede-ener-
gized to minimize the possibility of accidental start-
uporoperation, priortoattemptingrepairsoradjust-
ments. This is especially important when compres-
sors are remotely controlled.
G. Keep hands, feet, floors, controls and walking
surfaces clean and free of fluid, water or other liq-
uids to minimize the possibility of slips and falls.
1.6 HOT SURFACES, SHARP EDGES AND SHARP
CORNERS
A. Avoid bodily contact with hot fluid, hot coolant,
hot surfaces and sharp edges and corners.
B. Keep all parts of the body away from all points of
air discharge.
C. Wear personal protective equipment including
gloves and head covering when working in, on or
around the compressor.
D. Keep a first aid kit handy. Seek medical assis-
tance promptly in case of injury. DO NOT ignore
small cuts and burns as they may lead to infection.
1.7 TOXIC AND IRRITATING SUBSTANCES
A.DONOTuseairfromthiscompressorforrespira-
tion(breathing)exceptinfullcompliancewithOSHA
Standards 29 CFR 1910 and any other Federal,
State or Local codes or regulations.
DANGER
!
Death or serious injury can result from inhaling
compressed air without using proper safety
equipment.SeeOSHA standardsonsafetyequip-
ment.
B. DO NOT use air line anti-icer systems in air lines
supplying respirators or other breathing air utiliza-
tion equipment and DO NOT discharge air from
these systems in unventilated or other confined ar-
eas.
C. Operate the compressor only in open or ade-
quately ventilated areas.

Section 1
SAFETY
3
D. Locate the compressor or provide a remote inlet
sothatitisnotlikelytoingestexhaustfumesorother
toxic, noxious or corrosive fumes or substances.
E. Coolants and lubricants used in this compressor
are typical of the industry. Care should be taken to
avoid accidental ingestion and/or skin contact. In
the event of ingestion, seek medical treatment
promptly. Wash with soap and water in the event of
skin contact.
F. Wear goggles or a full face shield when adding
antifreeze compound to air line anti-icer systems.
G. If air line anti-icer system antifreeze compound
enters the eyes or if fumes irritate the eyes, they
should be washed with large quantities of clean
water for 15minutes. Aphysician, preferablyan eye
specialist, should be contacted immediately.
H. DO NOT store air lineanti-icer systemantifreeze
compound in confined areas.
I. The antifreeze compound used in air line anti-
freeze systems contains methanol and is toxic,
harmful or fatal if swallowed. Avoid contact with the
skin or eyes and avoid breathing the fumes. If swal-
lowed, induce vomiting by administering a table-
spoonofsaltineachglassof clean,warmwateruntil
vomit is clear, then administer two teaspoons of
baking soda in a glass of clean water. Have patient
laydownandcovereyestoexcludelight.Callaphy-
sician immediately.
1.8 ELECTRICAL SHOCK
A. This compressor should be installed and main-
tained in full compliance with all applicableFederal,
State and Local codes, standards and regulations,
including those of the National Electrical Code, and
alsoincludingthoserelativetoequipmentgrounding
conductors, and only by personnel that are trained,
qualified and delegated to do so.
B. Keep all parts of the body and any hand-held
tools or other conductive objects away from ex-
posed live parts of electrical system. Maintain dry
footing, stand on insulating surfaces and DO NOT
contact any other portion of the compressor when
making adjustments or repairs toexposed liveparts
of the electrical system. Make all such adjustments
or repairs with one hand only, so as to minimize the
possibility of creating a current path through the
heart.
C. Attempt repairs in clean, dry and well lighted and
ventilated areas only.
D. DO NOT leave the compressor unattended with
open electrical enclosures. If necessary to do so,
thendisconnect,lockoutandtagallpower atsource
so others will not inadvertently restore power.
E. Disconnect, lock out, andtag allpower at source
priortoattemptingrepairsoradjustments torotating
machinery and prior to handling any ungrounded
conductors.
1.9 LIFTING
A. If the compressor is provided with a lifting bail,
then lift by the bail provided. If no bail is provided,
then lift by sling. Compressors tobe airlifted by heli-
coptermustnotbesupportedbytheliftingbailbutby
slingsinstead. In anyevent, lift and/orhandleonlyin
full compliance withOSHA standards 29 CFR 1910
subpart N.
B. Inspect points of attachment for cracked welds
and for cracked, bent, corroded or otherwise de-
graded members and for loose bolts or nuts prior to
lifting.
C. Make sure entire lifting, rigging and supporting
structure has been inspected, is in good condition
andhasaratedcapacity of atleastthe weight ofthe
compressor. If you are unsure of the weight, then
weigh compressor before lifting.
D. Make sure lifting hook has a functional safety
latch or equivalent, and is fully engaged andlatched
on the bail or slings.
E. Use guide ropes or equivalent to prevent twisting
orswingingofthecompressoronceithasbeenlifted
clear of the ground.
F. DO NOT attempt to lift in high winds.
G.Keepallpersonnel outfrom underandawayfrom
the compressor whenever it is suspended.
H. Lift compressor no higher than necessary.
I. Keep lift operator in constant attendance when-
ever compressor is suspended.
J. Set compressor down only on a level surface ca-
pable of safely supporting at least its weight and its
loading unit.
K. When moving compressors by forklift truck, util-
ize fork pockets if provided. Otherwise, utilize pallet
if provided. If neither fork pockets or pallet are pro-
vided, then make sure compressor is secure and
well balanced on forks before attempting to raise or
transport it any significant distance.
L. Make sure forklift truck forks are fully engaged
and tipped back prior to lifting or transporting the
compressor.
M. Forklift no higher than necessary to clear obsta-
cles at floor level and transport and corner at mini-
mum practical speeds.
N. Make sure pallet-mounted compressors are
firmly bolted or otherwise secured to the pallet prior
to attempting to forklift or transport them. NEVER
attempttoforkliftacompressorthatisnotsecuredto
its pallet, as uneven floors or sudden stops may
cause the compressor to tumble off, possibly caus-
ingseriousinjuryorpropertydamageintheprocess.

Section 1
SAFETY
4
1.10 ENTRAPMENT
A. If the compressor enclosure is large enough to
holdamanandifitis necessarytoenterittoperform
service adjustments, inform other personnel before
doing so, or else secure and tag the access door in
the open position to avoid the possibility of others
closing and possibly latching the door with person-
nel inside.
B. Make sure all personnel are out of compressor
before closing and latching enclosure doors.

Section 2
DESCRIPTION
5
2.1 INTRODUCTION
Your new Sullair electric 2-stage, motor-driven air
compressor offers superior performance and reli-
ability requiring a minimal amount of maintenance.
Your compressor is equipped with a 2-stage Sullair
rotary screw air compressor. Compared to other
compressors, the Sullair is unique in mechanical re-
liability, with virtually no wear or loss of perform-
ance. With a Sullair compressor, there is noinspec-
tion required of the working parts within the com-
pressor unit.
As you will see in the following pages, it is very easy
tocarefor, and/or, tomaintainaSullaircompressor.
Bycareful andstep-by-stepadherencetotheguide-
lines and procedures, operator(s) will be able to
keep the compressor in top operational condition.
2.2 DESCRIPTION OF COMPONENTS
Refer to Figure 2-1 and 2-2. The components of the
Sullair 2-stage electric compressor include com-
pressor unit,electric motor,cooling and lubri-
cationsystem,airinletsystem,compressordis-
charge system,capacity control system and in-
strument panel.
The 2-stage Sullair compressor unit is driven by an
electric motor designed to provide enough horse-
power for more than adequate reserve at rated con-
ditions.
On air-cooled models, a separate motor-driven fan
forces air through the cooler, thereby removing the
heat of compression from the cooling fluid.
Provisions are made for easy access to such com-
ponents as thefluid filters, control valves and the air
filter. There will be no problem in gaining access to
any components in the event they require service.
2.3 SULLAIR COMPRESSOR UNIT, FUNCTIONAL
DESCRIPTION
Thecompressorunit suppliedwithyourcompressor
isa2-stage,positivedisplacement, floodlubricated-
type rotary screw air compressor.
Figure 2-1 Sullair 20/12 Rotary Screw Air Compressor (Air-cooled)

Section 2
DESCRIPTION
6
Figure 2-2 Sullair 20/12 Rotary Screw Air Compressor (Water-cooled)
As the rotors turn, air is drawn into the compressor
unit at the first stage inlet. At the outlet of the first
stage the air is compressed and discharged into the
secondstagewhereitiscompressedagaintoobtain
a higher pressure.
Lubricating fluid is injected into the compressor unit
ateachstagewhichmixesdirectlywiththeairasthe
rotors turn, compressing the air. The fluid flow has
three basic functions:
1. As coolant, it controls the rise of air temperature
normally associated with the heat of compres-
sion.
2. It seals the leak paths between the rotors as well
as between the rotors and stators.
3. It acts as a lubricating film between the rotors al-
lowingthemalerotorstodirectly drivethefemale
rotors (which are idlers).
After the air has been compressed in both stages of
the compressor unit, it is discharged in the form of
an air/fluid mixture. This mixture is routed through
the discharge system where the fluid is separated
from the air. At this time,theairflowstoyourservice
line and the fluid is directed through the cooling and
lubrication system in preparation for reinjection.
2.4 COMPRESSOR COOLING AND LUBRICATION
SYSTEM, FUNCTIONAL DESCRIPTION
Refer to Figures 2-3,2-4 and 2-5. The compressor
cooling and lubrication system is designed to pro-
vide adequate lubrication as well as maintain the
proper operating temperature of the compressor.
The system is comprised of a shell and tube or ra-
diator type heat exchanger, main line filter, extra-
finebearinglubefilter,thermalvalve,fluidstopvalve
and interconnecting piping.
Fluidisusedinthesystemasacoolantandlubricant
and is housed in the receiver/sump (from this time
forward, the receiver sump will be referred to as the
sump). Fluid circulation is achieved by forcing the
fluid from the higher pressure area of the sump to
lower pressure regions at the compressor unit.
Fluid flows from the bottom of the sump to the ther-
mal valve. The thermal valve is fully open to the
compressorunitwhenthefluidtemperatureisbelow
220ºF (104ºC).

Section 2
DESCRIPTION
7
Figure 2-3 Compressor Cooling/Lube and Discharge (Air-cooled)
After the fluid passes through the thermal valve, it is
thendirectedthroughthefluidfilter.Therethefluidis
filtered in preparation for injection into the compres-
sion chambers. This filter has a cleanable element
and built-in bypass which allow some fluid to flow
even when the filter becomes plugged and requires
changing, or when the viscosity of the fluid is too
high for adequate flow. After the fluid is properly fil-
tered, it then flows to the fluid stop valve and on to
the bearing filter.
The fluid stop valve prevents the fluid from filling the
compressor unit when it is shut down. When the
compressor is in operation, the fluid stop valve is
held open by air pressure from the compressor unit
allowingafreeflowoffluidfromthesumpbacktothe
compressorunit.Onshutdown,thecompressorunit
pressure is reduced, causing the fluid stop valve to
close and isolate the unit from the cooling system.
The fluidstopvalve solenoidvalve alsoopens to as-
sistinrelievingthestopvalvepilotsignalpressureat
shutdown.
A portion of the fluid flowing to the compressor is
routedtotheanti-frictionbearingswhichsupportthe
rotors inside the compressor unit. Prior to entering
the compressor unit, this fluid is taken through an
extra-fine bearing filter, thus assuring properly fil-
tered fluid for bearing supply.
The bearing filter has a replaceable element and an
integral pressure bypass valve. An associated
maintenance indicator shows red when the filter
needs servicing. This indicator has a pressure set-
ting lower than that of thebypass valve. After the in-
itial50hourfilterchange,thefilterindicatorwillshow
red when filter conditions require a filter change.
2.5 COMPRESSOR DISCHARGE SYSTEM, FUNC-
TIONAL DESCRIPTION
Refer to Figures 2-3,2-4 and 2-5. The Sullair com-
pressor unit discharges the compressed air/fluid
mixture through a discharge check valve into the
combination receiver/sump. The discharge check
valve prevents air in the sump from returning to the
compression chamber after the compressor has

Section 2
DESCRIPTION
8
Figure 2-4 Compressor Cooling/Lube and Discharge System (Water-cooled)
been shut down. The receiver has three basic func-
tions:
1. It acts as a primary fluid separator.
2. It serves as the compressor fluid sump.
3. It houses the final fluid separator element.
The compressed air/fluid mixture enters the re-
ceiver and is directed against the wall of the sump.
By change of direction and impingement action, the
larger dropletsof fluidfall to the bottom of thesump.
The fractional percentage of fluid remaining in the
compressed air collects on the surface of the final
separatorelementsastheairflowsthroughthesep-
arators. As more and more fluid collects on the sur-
face of the elements, the fluid descends to the bot-
tom of theseparators, wherereturn lines(scavenge
tubes) lead from the bottom of the separator ele-
ments to the compressor unit. Fluid collected at the
bottom of the elements is returned to the compres-
sor unit by a pressure difference between the area
surrounding the separator elements and the com-
pressor. Orifices (protected by strainers) are in-
serted in the return lines to assure proper flow.
ThesumpisASMEcoderatedat 400psig(27.6bar)
working pressure. A minimum pressure valve, lo-
cated downstream from the separator, assures a
minimum receiver pressure of 160 psig (11 bar),
which is maintained during all conditions. This pres-
sure is necessary for proper fluid circulation andair/
fluid separation.
A pressure relief valve (located on the wet side of
theseparator)issettoopenifthesumppressureex-
ceeds 375 psig (25.9 bar). Also a temperature
switch will shut down the compressor when the dis-
charge temperature reaches 265ºF (130ºC) on first
stage or 265ºF (130ºC) on second stage.
All Sullair compressor models are equipped with a
high pressure shutdown switch to shut down the
compressorat365psig(25.2bar).Thispreventsthe

Section 2
DESCRIPTION
9
Figure 2-5 Piping and Instrumentation
RESTRICTION

Section 2
DESCRIPTION
10
pressure relief valve from opening under routine
conditions, thereby preventing fluidloss through the
pressure relief valve.
Fluid is added to the sump via a capped fluid filler
opening, placed low on the tank to prevent overfill-
ing. A sight glass enables the operator to visually
monitor the sump fluid level.
WARNING
!
DO NOT open the fluid filler cap when the com-
pressor is pressurized. Shut down the compres-
sor and bleed the sump to 0psig beforeremoving
the cap.
A check valve is also provided to prevent air in the
service line from bleeding back into the sump at
shutdown or when the compressor is being run in
parallel with other compressors tied to a large sys-
tem. It is recommended that an optional gate-type
service valve be used downstream of the check
valvebeforethepointatwhichservicelines arecon-
nected.
An indicator, located on the instrument panel, sig-
nals red if abnormal pressure drop through the
separator elements develops. At this time, separa-
tor element replacement is necessary.
2.6 CAPACITY CONTROL SYSTEM, FUNCTIONAL
DESCRIPTION
Refer toFigure2-6.Thepurposeofthe compressor
control system is to regulate the compressor air in-
take to match the amount of compressed air being
used.
The Control System consists of a pneumatic ac-
tuator cylinder,abutterfly valve (located on the
compressor air inlet), a pilot pressure regulator
valve,asolenoid pilot valve,closed inlet sole-
noid valve,Sullicon Control and a blowdown
valve.
The functional description of the Control System is
described below in five distinct phases of compres-
sor operation. For explanation purposes, this de-
scriptionwill applytocompressorswithanoperating
pressure rangeof 340to 360psig(23.5to 24.8 bar).
A compressor with any other pressure range would
operate in the same manner except for the stated
pressures.
START MODE - 0 TO 160 psig (0 TO 11 BAR)
When the compressor START button is depressed,
thesumppressurewillquicklyrisefrom0to160psig
(0 to 11 bar). During this period, both the pilot pres-
sure regulator and the solenoid pilot valve are
closed and the inlet cylinder is inoperative. Until the
closedinlet timeris satisfied, theinlet actuatorcylin-
der remains withdrawn holding the inlet butterfly
valveclosed(start Mode A).Whenthetimerissatis-
fied, the closed inlet solenoid valve opens allowing
the cylinder to extend, opening the butterfly valve
fullyandthecompressorthenpumpsatfullratedca-
pacity (start Mode B). The rising compressed air
pressure is isolated from the service line in this
phase by the minimum pressure valve, set at ap-
proximately 160 psig (11 bar).
NORMAL OPERATING MODE - 160 TO 340 PSIG
(11 TO 23.4 BAR)
When the sump pressure rises above 160 psig (11
bar), the minimum pressure valve opens and deliv-
ers compressed air to the service line. From this
point on, the line air pressure is continually moni-
tored by a line pressure gauge. The pilot pressure
regulator and the solenoid pilot valve remain closed
duringthisphase,keepingtheSulliconControlinac-
tive.
MODULATING MODE - 340 TO 360 PSIG (23.4
TO 24.8 BAR)
If less than the rated capacity of compressed air is
being used, the service line pressure will rise above
340 psig (23.4 bar). The pilot pressure regulator
valve gradually opens, applying air pressure to the
Sullicon Control which partially closes the butterfly
valve on the compressor air inlet reducing the
amount of air entering the compressor until it
matches the amount of air being used. The Control
System functions continually in this manner, be-
tweenthelimitsof 340to360psig(23.4to 24.8bar),
in response to varying demands from the service
line.
The pilot pressure regulator has an orifice which
vents a small amount of air to the atmosphere when
the pressure regulator controls the butterfly valve.
UNLOAD MODE - IN EXCESS OF 360 PSIG (24.8
BAR) LINE PRESSURE
When a relatively small amount or no air is being
used, the service line pressure rises to the setting
(cut-out pressure) of the pressure switch. Thepres-
sure switch opens, interrupting the electrical power
to the solenoid-type pilot valve. At this time, this so-
lenoid valve allows dry sump tank air pressure to be
applied directly to the Sullicon Control keeping the
butterflyvalveclosed. Simultaneously,thissolenoid
valve sends a pneumatic signal to the blowdown
valve. The blowdown valve opens the sump to the
atmosphere, reducing the sump pressure to ap-
proximately 160 to 180 psig (11 to 12.4 bar).
The check valve in the air service line prevents the
pressure from returning to the sump.
At a 0 to 10 percent air output, the control system
will automatically blow down the sump and greatly
reduce the unload power consumption.
Whenthelinepressuredropsbacktothelowsetting
(cut-inpressure) ofthepressureswitch(usually340
psig[23.4bar]),thepressureswitchcloses,re-ener-
gizing the three-way solenoid pilot valve and allow-
ing the blowdown valve to close. The re-energized
solenoid valve again prevents line pressure from

Section 2
DESCRIPTION
11
reaching the Sullicon Control. Should the pressure
begintorise,thepilot pressureregulator willresume
its normal function as previously described.
For a compressor with varied periods of time when
there are no air requirements, a “Dual Control” op-
tion is available. This option allows you to set the
compressor in an automatic position whereby the
compressor will shut down (time delayed) when no
compressed air requirement is present and restart
as compressed air is needed.
2.7 AIR INLET SYSTEM, FUNCTIONAL DESCRIP-
TION
Refer to Figure 2-7. The compressor inlet systems
consists of a dry-type air filter, a restriction gauge,
inlet actuator cylinder, Sullicon Control, and an air
inlet valve.
Therestrictiongauge,locatedonthecompressorin-
strument panel, indicates when air filter mainte-
nance is required.
The butterfly-type air inlet valve directly controls the
amount of air intake to the compressor in response
totheoperationoftheSulliconControl(Section2.6).
The inlet actuator cylinder holds the butterfly valve
closed during the compressor start mode.
2.8 INSTRUMENT PANEL GROUP, FUNCTIONAL
DESCRIPTION
Refer to Figure 2-8 for specific location of parts de-
scribed. The instrument panel group consists of a
line pressure gauge,air filter maintenance
gauge,sump pressure gauge,compressor dis-
charge temperature gauge and maintenance in-
dicators for the separator elements and bearing
filteralllocatedonaheavygaugeinstrumentpanel.
Located on the electric control panel are START,
STOP and RESET (optional) pushbuttons, power
and run indicators,anhourmeter, plus various
(optional) fault indicator lights (see Figure 2-8).
Refer toFigure2-8for functionallocationsof thefol-
lowing indicators and controls:
STheline (terminal) pressure gauge isconnected
to the dry side of the receiver downstream from the
check valve and continually monitors the air pres-
sure.
Figure 2-6 Control System

Section 2
DESCRIPTION
12
SThe sump pressure gauge continually monitors
thesumppressureatthevariousloadand/orunload
conditions.
SThe discharge temperature gauge monitors the
temperature of the air leaving the compressor unit.
The normal reading for the compressor is 230ºF
(110ºC).
Figure 2-7 Air Inlet System (Typical)
Figure 2-8 Instrument Panel
SThe START pushbutton turns the compressor
on.
STheSTOP pushbutton turns the compressor off.
SThe RESET (optional) pushbutton clears the
protectiveshutdowninterlocksafterafault hasbeen
corrected.
SThe hourmeter records the cumulative hours of
operation for the compressor and is useful for plan-
ning and logging service operations.
SThe separator maintenance indicator monitors
the condition of the separator elements and shows
red when the element restriction is excessive.
SThe bearing lube filter maintenance indicator
monitors the condition of the bearing filter element
and shows red when the element should be
changed. This indicator is automatically reset.

Section 3
SPECIFICATIONS
13
3.1 SPECIFICATIONS
DIMENSIONS WITHOUT ENCLOSURE
Model Series Length Width Height Weight
CFM/PSIG/HP in mm in mm in mm lb kg
20/12 (500/250/200) 120 3048 72 1829 75 1905 8500 3856
20/12 (500/350/200) 120 3048 72 1829 75 1905 8500 3856
20/12 (600/225/200) 120 3048 72 1829 75 1905 8500 3856
20/12 (630/350/250) 120 3048 72 1829 75 1905 9000 4082
20/12 (750/250/250) 120 3048 72 1829 75 1905 9000 4082
20/12 (750/350/300) 120 3048 72 1829 75 1905 9000 4082
COMPRESSOR:
Type: 2-Stage Oil Flooded Rotary
Maximum Full Load Operating Pressure: 350 psig (24.1 bar)
Bearing Type: Anti-Friction
Cooling: Pressurized Compressor Fluid
Lubricant: Sullube 32
Sump Capacity: 35 U.S. Gallons (132.5 liters)
Control: Electro-Pneumatic
MOTOR:
Type: O.D.P., 460V, A.C., Three Phase, 60 Cycles
Size: See Model Series above.
Speed: a) 1800 RPM and b) 1200 RPM for 500 CFM units.
3.2 LUBRICATION GUIDE
Sullair standard compressors are filled with Sullube
32 fluid as factory fill. MIXING OF OTHERFLUIDS
WITHIN THE COMPRESSOR WILL VOID ALL
WARRANTIES.
Sullube 32 fluid should be changed every 8000
hours when indicated by fluid analysis or once a
year, whichever comes first. The fluid should be
changed more frequently under severe operating
conditions,suchashighambient temperaturescou-
pled with high humidity, or when high particulate
level, corrosive gases or strong oxidizing gases are
present in the air.
Maintenance of all other components is still recom-
mended as indicated in the Operator’s Manual.
Sullair encourages the user to participate in a fluid
analysis program with the fluidsuppliers. This could
result in a fluid change interval differing from that
stated in this manual. Contact your Sullair Repre-
sentative for details.

14
NOTES

Section 4
INSTALLATION
15
4.1 MOUNTING OF COMPRESSOR
A foundation or mounting capable of supporting the
weightof thecompressor,andrigidenoughtomain-
tainthecompressorframelevelandthecompressor
in alignment is required. The compressor frame
must be leveled and secured with foundation bolts,
and full uniform contact must be maintained be-
tween the frame and foundation. It is recommended
that the frame be grouted to the foundation. The
compressor unit and driver must be aligned after in-
stallation as specified in the Operator’s Manual. No
piping loads shall be transmitted to the compressor
at the external connections.
4.2 SERVICE AIR PIPING
Service air piping should be installed as shown in
Figure 4-1. A shut-off valve should be installed to
isolate the compressor from the service line. Also
notice that the service line should be equipped with
water legs and condensate drains throughout the
system.
NOTE
Under certain conditions for inside installations,
it may be desirable to pipe the relief valves to the
outside of the building.
4.3 COUPLING ALIGNMENT CHECK
In preparation for the factory test, the coupling sup-
plied with your compressor is properly aligned for
operation. The motor is flange-mounted to the com-
pressor unit. Therefore it is not necessary to re-
check this alignment.
4.4 FLUID LEVEL CHECK
The2-stage aircompressor isalsosuppliedwiththe
proper amount of fluid. However, it is necessary to
check the fluid level at installation. The level is
checked by looking at the sight glass located near
thesump. If thesumpis properly filled,thefluidlevel
should be visible in middle of the sight glass. DO
NOT OVER FILL THE FLUID LEVEL OF THE
COMPRESSOR.
4.5 MOTOR ROTATION DIRECTION CHECK
Aftertheelectricalwiringhas beendone,it is neces-
sarytocheckthedirectionofthemotorrotation.This
can be done by jogging the START and STOP but-
tons on the instrument panel. When looking at the
motor from the end opposite the compressor unit,
the shaft should be turning clockwise. If the motor
shaft is not turning clockwise, disconnect the power
to the starter and exchange any two of the three
power input leads, then re-check rotation.
4.6 ELECTRICAL PREPARATION
Interior electrical wiring is performed at the factory.
Required customer wiring is minimal, but should be
done by a qualified electrician in compliance with
OSHA, National Electrical Code, and any other ap-
plicable local electrical code concerning isolation
switches, fused disconnects, etc. Sullair provides a
wiring diagram for use by the installer.
A few electrical check should be made to help as-
sure that the first start-up will be trouble free.
DANGER
!
Lethal shock hazard inside.
Disconnectall power at source before openingor
servicing.
1. Check incoming voltage. Be sure that the incom-
ingvoltageisthesamevoltagethatthecompres-
sor was wired for.
2. Check starter and overload heater sizes (see in-
strument panel and electric control box in Parts
List Manual P/N 02250041-547).
3. Check all electrical connections for tightness.
4. “DRY RUN” the electrical controls by disconnect-
ing thethree (3) motor leads from the starter. En-
ergize the control circuits by pushing the START
buttonandcheckallprotectivedevicestobesure
thattheywillde-energizethestartercoilwhenac-
tivated.
5. Reconnect the three (3) motor leads and jog the
motor for a direction of rotation check, as ex-
plained in Section 4.5.
Figure 4-1 Service Air Piping

16
NOTES