ZEKS Eclipse 90ZPA User manual

TECHNICAL MANUAL
ZEKS Compressed Air Solutions
1302 Goshen Parkway
West Chester, PA 19380
Phone: [phone]
800-888-2323
Fax: [phone]
Web: www.zeks.com
Form: ZEKS ZPA NEMA 1 V0813
ZPA Heatless Purge
Desiccant Compressed Air Dryer
90-5000 scfm
NOTICE
Those operating the machine or performing
maintenance should read and understand
the decals positioned on the machine and
the contents of this Technical Manual.
Ensure that this Technical Manual is not
removed permanently from the machine.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
TABLE OF CONTENTS
SECTION CONTENT PAGE
1. INTRODUCTION ............................................................................................. 2
2. ABBREVIATED WARRANTY .......................................................................... 2
3. ZPAHEATLESS DRYER NOMENCLATURE .................................................. 3
4. RECEIVING AND INSPECTION ..................................................................... 3
5. SAFETYAND OPERATION PRECAUTIONS ................................................. 4
6. PRINCIPLES OF OPERATION ....................................................................... 5
7. ALARMS AND INDICATORS .......................................................................... 7
8. INSTALLATION/INITIAL START-UP ................................................................ 8
9. SCHEDULED MAINTENANCE ....................................................................... 10
10. TROUBLESHOOTING .................................................................................... 13
11. PURGE CHARTS ............................................................................................14
12 GENERALARRANGEMENT DRAWINGS ...................................................... 18
13 WIRING DIAGRAMS .......................................................................................21
14 FLOW DIAGRAM ............................................................................................ 23
15 FILTER FLOW ................................................................................................. 25
16 FILTER ARRANGEMENT ................................................................................26
17 REPLACEMENT PARTS DIAGRAM ............................................................... 27
18 REPLACEMENT PARTS LIST ........................................................................ 30
1

ZEKS Eclipse™ Heatless Desiccant Dryers are designed
to adsorb moisture from compressed air. The dryers are
constructed with two towers, each containing desiccant-
beads, that alternate between online (drying) and offline
(regenerating) modes, yielding a continuous stream of dry
air at the dryer’s outlet.
During normal operation, wet air passes through the online
tower and water vapor from the air is adsorbed (collected)
on the desiccant beads. While air is being adsorbed in the
online tower, the moisture on the desiccant in the offline
tower is removed by a process called desorption (regen-
eration). After an initial rapid depressurization, a portion
of dried air from the online tower passes over the desic-
cant bed and carries the moisture off the bed and out the
dryer’s exhaust.
The continuous, alternating process of adsorption and de-
sorption is controlled using a timer that switches the tow-
ers in a specific timed sequence. Very dry compressed air
dew points are achieved through the continuous switching
and operation of this dryer. ZEKS offers dryers to provide
either -40°F, -80°F or -100°F pressure dew point outlet air.
1.0 INTRODUCTION
ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
2
2.0 ABBREVIATED WARRANTY
ZEKS Eclipse™ heatless desiccant dryer products are
warranted to be free from defects in material and work-
manship for a period of 12 months from the original date
of shipment from the factory. To allow the warranty to be in
effect for 12 months from the date of equipment start-up,
the Warranty Registration Card must be completed and
returned to ZEKS. Alternately, the Warranty Registration
Card may be completed online at www.zeks.com. The
total warranty period cannot exceed 18 months from the
original date of shipment from the factory.
Equipment must be installed and operated in accordance
with ZEKS’ recommendations. ZEKS liability is limited to
repair of, refund of purchase price paid for, or replace-
ment in kind at ZEKS’ sole option, during the warranty
time period stated above. IN NO EVENT SHALL ZEKS
BE LIABLE OR RESPONSIBLE FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES, even if the possibility of
such incidental or consequential damages has been made
known to ZEKS CompressedAir Solutions. In addition, the
usual maintenance and replacement type products are not
covered by this warranty. See SECTION 9.
The warranties expressed above are in lieu of and exclu-
sive of all other warranties. There are no other warranties,
expressed or implied, except as stated herein. There are
no implied warranties of merchantability or fitness for a
particular purpose, which are specifically disclaimed.
Valves – After the Basic Warranty noted above expires,
the diaphragm valves on the ZPAheatless dryers are war-
ranted (parts only) for a total of 5 years from the date the
dryer is shipped from the ZEKS factory. The following ap-
plies to this warranty:
A.Check valves are excluded
B.Not applicable to dryers provided for -80°F and
-100°F dewpoint applications
C.Valves must be rebuilt every two years. Refer to
SECTION 9 of this manual
D.Control line air filter element must be replaced
once per year.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
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Nominal Flow Type/Design Voltage Electrical
SCFM* Series (Dew Point) NEMA Option
90 ZPA = Pressure Swing 1 = 115-1-60 (-40°F) 0 = NEMA1 0 = Standard
120 G = 115-1-60 (-80°F) H = NEMA4 A= Failure-To-Shift (FTS)
160 B = 115-1-60 (-100°F) S = NEMA4X B = High Humidity (HH)
200 2 = 230-1-60 (-40°F) Stainless Steel C = FTS + HH
250 C = 230-1-60 (-100°F) E = Dew Point Display
300 3 = 220-1-50 (-40°F) + MLC (NEMA4/4X)
400 E = 220-1-50 (-100°F) G = Dew Point Display + MLC
500 + FTS (NEMA4/4X)
600 M = Moisture Load Control (MLC)
800 + FTS (NEMA1 only)
1000 N = MLC + HH (NEMA1 only)
1200
1500
1800
2100
2700
3300
4000
5000
* Nominal Flows indicated are
for 100F inlet temperature,
100°F ambient temperature and
100 psig compressed air pressure.
3.0 NOMENCLATURE
4.1 INSPECTION
Uponreceiving yourZEKS air dryer, pleaseinspect theunit
closely. If evidence of rough handling is detected, please
note it on your delivery receipt, especially if the dryer will
not be uncrated immediately. Obtaining the delivery per-
son’s signed agreement to noted damages will facilitate
submission of insurance claims.
4.2 UNPACKING AND HANDLING
Refer to labels on the dryer for the appropriate means for
lifting or moving the dryer. For those dryers that indicate
lifting via the structural skid, forks should extend all the
way through the skid to reduce unnecessary forces to the
dryer when moving. When lifting the dryer, ensure that
no stress is applied to the piping or the valves. Refer to
Section 8.2 for locating and mounting of dryer.
4.0 RECEIVING AND INSPECTION
!NOTICE
Nomenclature shown above represents standard
price sheet options. Other options are available -
refer to nomenclature insert specific to your dryer
for details.
!NOTICE
Under no circumstances should any person attempt
to lift heavy objects without proper lifting equipment
(i.e.: crane, hoist, slings or fork truck). Lifting any unit
without proper lifting equipment can cause serious
injury.

Because an air dryer is pressurized and contains me-
chanical parts, the same precautions should be observed
as with any piece of machinery of this type where care-
lessness in operation or maintenance is hazardous to per-
sonnel. In addition to the many obvious safety rules that
should be followed with this type of machinery, the safety
precautions as listed below must be observed:
1. Only qualified personnel shall be permitted to adjust,
perform maintenance or repair this air dryer.
2. Read all instructions completely before operating unit.
3. Pull main electrical disconnect switch and disconnect
any separate control lines, if used, before attempting to
work or perform maintenance on the unit.
4. Do not attempt to service any part while dryer is in an
operational mode.
5. Do not attempt to remove any parts without first reliev-
ing the entire air system of pressure.
6. Do not operate the dryer at pressures in excess of its
rating.
7. Inspect unit daily to observe and correct any unsafe
operating conditions.
OSHA Heading Descriptions
5.0 SAFETY AND OPERATION PRECAUTIONS
ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
4
!NOTICE
The user of any air dryer manufactured by ZEKS Com-
pressed Air Solutions, is hereby warned that failure to
follow the above Safety and Operation Precautions can
result in personal injuries or equipment damage. How-
ever, ZEKS CompressedAir Solutions does not state as
fact, nor does it mean to imply, that the preceding list of
Safety and Operating Precautions is all inclusive, and
further, that the observance of this list will prevent all
personal injuries or equipment damage.
!WARNING
“Warning”isusedtoindicateahazardoussituationwhich
has some probability of death or severe injury. Warn-
ing should not be considered for property damage ac-
cidents unless personal injury risk is present.
!CAUTION
“Caution” is used to indicate a hazardous situation which
may result in minor or moderate injury.
!NOTICE
“Notice” is used to indicate a statement of company
policy as the message relates directly or indirectly to
the safety of personnel or protection of property. Notice
should not be associated directly with a hazard or haz-
ardous situation and must not be used in place of “Dan-
ger,” “Warning,” or “Caution.”

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 5
6.1 INTRODUCTION
As described in Section 1, water vapor is removed from
compressed air by diverting air flow alternately between
two towers filled with desiccant. While one tower process-
es the compressed air stream, adsorbing water vapor, the
opposite tower is regenerated by desorbing the water va-
por and venting it to atmosphere. Refer to the Process and
Instrumentation Diagram (P&ID) for a visual representa-
tion of the drying and regenerating cycles.
Timing of the drying and regenerating cycles is automati-
cally controlled by a Solid State Timer (SST). An optional
programmable dryer controller is available.
6.2 DRYING CYCLE
Saturated compressed air enters the dryer and is diverted
to the appropriate tower by the Inlet Flow Valves. Refer-
ring to the P&ID, the Left Inlet Flow Valve is actuated to a
closed position to prevent air flow from entering the regen-
erating tower. Simultaneously, the Right Inlet Flow Valve
is actuated to an open position, allowing air flow to the
right hand tower. During this time, the Right Tower Purge
Valve is actuated to a closed position, preventing the
compressed air from venting to atmosphere. As the com-
pressed air flows through the desiccant material at pres-
sure, removal of water vapor from the air stream begins
to occur through adsorption. In the adsorption process,
the desiccant material draws water vapor out of the com-
pressed air and “holds” it until the right tower drying cycle
is complete. Compressed air flows out of the tower for de-
livery to the process use. The Outlet Flow Check Valves
provide air flow diversion to the outlet air connection of the
dryer. The Right Outlet Flow Check Valve allows air flow
through to the outlet connection of the dryer while The Left
Outlet Flow Check Valve checks off to prevent flow back to
the regenerating tower.
6.3 REGENERATION CYCLE
Previously adsorbed moisture, removed from the process
stream, gets stripped or desorbed from the desiccant ma-
terial in the regeneration process. The first stage of re-
generation is tower depressurization. After the Inlet Flow
Valves are switched to divert air flow away from the regen-
erating tower, the appropriate Purge Valve will be opened
and the tower will be depressurized. Through rapid de-
pressurization, a significant portion of the previously ad-
sorbed water vapor is stripped off of the desiccant material
and exhausted to atmosphere.
The second stage of regeneration uses a portion of the
dry, compressed air, expanded to atmospheric pressure to
complete the desorption process. As shown on the P&ID,
the compressed air exits the drying tower and a portion of
the air flows through the Purge Adjustment Valve and the
Purge Orifice. Once the air has passed through the Purge
Orifice, it expands to atmospheric pressure and continues
the regeneration process. Desorption occurs as the desic-
cant releases water vapor into the regeneration air and is
exhausted through the Purge Muffler.
Eclipse Heatless Dryers may be equipped with an optional
Downstream Purge feature. By adding additional check
valves to the upper manifold, a dryer equipped with the
Downstream Purge option is able to use air from a down-
stream source to purge the regenerating tower. This op-
tional feature is useful for applications with downstream
(dry) storage tanks, as pulling air from a downstream
source can minimize cycling of the air compressor.
6.4 SETTING THE REGENERATION AIR FLOW
It is necessary to manually set the purge air flow to achieve
proper dryer performance. Setting the purge flow too high
will waste compressed air and if set too low, the dryer will
not achieve proper dew point performance.
The purge adjustment manifold consists of the Purge Ad-
justment Valve, the Purge Pressure Gauge and the Purge
Orifice. When the left tower is the drying tower (pressur-
ized) and the right tower is depressurized (0 PSIG), man-
ually adjust the Purge Adjustment Valve until the gauge
reading on the purge pressure gauge matches the Purge
Pressure Gauge setting listed on the laminated tag affixed
to the Orifice Plate Assembly.
6.0 PRINCIPLES OF OPERATION
!NOTICE
The right tower must be the drying tower for proper
purge adjustment setting. When the left tower is the
drying tower, the Purge Adjustment Gauge will read
close to line pressure.
!NOTICE
On dryers equipped with the optional NEMA 4/DPC™
Package, or when using the optional Moisture Load
Control feature, the purge valve MUST be set to the
factory set point to ensure proper operation of these
features. See Appendix A-6.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
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6
6.5 TOWER REPRESSURIZATION
Upon completion of tower regeneration, and prior to the
Inlet Flow Valves changing position to switch towers, the
regenerated tower must be repressurized.
Repressurization is accomplished when the appropriate
Purge Valve closes. Closing the Purge Valve allows the
regeneration air to begin to pressurize the tower. In ad-
dition to the regeneration air, the Repressurization Valve,
(standard on -80°F and -100°F dew point and high pres-
sure dryers; optional on -40°F dew point dryers) opens al-
lowing some additional air from the outlet of the dryer to
ensure adequate pressurization.
6.6 VALVES
Solenoid valves are used to actuate the Flow Valves,
Purge Valves and the optional Repressurization Valve on
Eclipse Heatless Dryers. The Inlet Flow Valves and op-
tional Repressurization Valve are normally open valves,
while the Purge Valves are connected as normally closed
valves. This arrangement permits air to flow through the
dryer during periods of loss of power.
Outlet Check Valves are single direction check valves that
will allow flow in the direction shown on the P&ID, but not
allow flow in the opposite direction.
6.7 TIMING SEQUENCE
All timing functions on NEMA 1 dryers are performed by
the Solid State Timer (SST) and on NEMA 4 dryers by
ZEKS DPC™ Controller. Regardless of controller, the tim-
ing of ZEKS -40°F, -80°F and -100°F dryers is as follows:
6.7.1 TIMING CYCLE FOR -40°F DEW POINT DRYERS
Thestandard timing cyclefor-40°Foperationswitch-
es the Inlet Flow Valve position every five minutes
which alternates the drying tower. At the same time
as a tower Inlet Valve opens, the appropriate tower
Purge Valve opens to depressurize the regenerating
tower. Tower regeneration occurs for 4 minutes and
15 seconds, at which time the Purge Valve closes to
initiate repressurization.
6.7.2 TIMING CYCLE FOR -80°F AND -100°F DEW
POINT DRYERS
The standard timing cycle for both -80°F and -100°F
operation switches the Inlet Flow Valve position ev-
ery 2 minutes which alternates the drying tower. At
the same time a tower Inlet Valve opens, the appro-
priate tower Purge Valve opens to depressurize the
regenerating tower. Tower regeneration occurs for
1 minute and 50 seconds, at which time the Purge
Valve closes to initiate repressurization. The Re-
pressurization Valve opens to assist tower repres-
surization for the last 10 seconds prior to Inlet Flow
Valve switching.
6.0 PRINCIPLES OF OPERATION
!NOTICE
Failure to re-pressurize prior to tower switchover will re-
sult in shocking the desiccant material and cause pre-
mature desiccant dusting.
Refer to Appendix A6,
PRINCIPLES OF OPERATION for dryers equipped
with the optional NEMA 4/DPC Package.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
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7.1 MOISTURE INDICATOR
The Blue Moisture Indicator (BMI) analyzes a sample of
the control air supply which is taken from the dryer outlet.
The BMI provides an indication of dew point deterioration
at the outlet of the dryer. Under normal operating condi-
tions, the BMI appears blue. In the event of a dryer mal-
function or prolonged dryer shut down, it will turn gray in
the presence of moisture.
7.2 FAILURE-TO-SHIFT ALARM (Optional)
The Failure-to-ShiftAlarm provides an indication of switch-
ing failure in one of the dryer switching valves. The Fail-
ure-to-Shift Alarm uses a pressure switch to monitor the
pressure in each tower.
At “0” PSIG the switches are normally closed which
sends a signal to the controller. When the towers pres-
surize, the switches open, thus removing the signal to
the controller. The controller anticipates the appropri-
ate open and closed switch position based on its timing
sequence. On dryers equipped with NEMA 1 electrics,
if either switch is in an incorrect position, the Failure-
to-Shift Alarm light will illuminate. The alarm light will
remain illuminated and the dryer will continue the operat-
ing sequence until the problem is corrected.
On dryers equipped with the optional NEMA 4/DPC
Package, Refer to Appendix A7, ALARMS AND INDI-
CATORS for description and explanation of alarms.
7.3 HIGH HUMIDITY ALARM (Optional)
The purpose of the High Humidity Alarm is to provide the
operator an indication if the equipment fails to supply air at
its designed dew point. This is accomplished by passing a
sample of dried air from the control line across a sensing
element. If the sensing element is exposed to air with a
dew point of -10°F or higher (for -40°F dryers), the sen-
sor sends a signal to the humidistat. On NEMA 1 dryers,
power is then supplied to the red alarm light on the enclo-
sure. This light will remain illuminated until the problem is
corrected and the sensing element has dried out.
On dryers equipped with the optional NEMA 4/DPC
Package, Refer to Appendix A7, ALARMS AND INDI-
CATORS for description and explanation of alarms.
7.4 MOISTURE LOAD CONTROL (Optional)
The Moisture Load Control (MLC) feature is designed to
minimize the loss of purge air during low flow or low wa-
ter loading conditions. On -40°F units, a sensor samples
the moisture content from the online tower and provides
a signal to a humidistat. As long as the humidistat finds
that the air in each tower is dry, it will not allow the control-
ler to open the Purge Valves. Once the moisture content
in either tower is found to reach the threshold point, the
humidistat sends a signal to the controller and initiates the
regeneration cycle. For -80°F and -100°F dryers, a digital
dew point monitor is used in place of the humidistat.
Refer to Appendix NEMA 4 / DPC™ Package for cor-
rect operation of NEMA 4-equipped dryers with the
DPC™ Microprocessor Controller.
7.0 ALARMS AND INDICATORS

8.1 APPLICATION AND CHECK ANALYSIS
To achieve the best dryer performance, you should care-
fully check that the design and installation requirements
outlined below are satisfied.
Operating pressure of ZEKS Eclipse dryers can range
from 75 -150 PSIG. Air available for your usage will vary
with operating pressure. The maximum allowable working
pressure of the standard Eclipse ZPA Heatless Dryer is
150 PSIG. Consult your ZEKS representative for units re-
quiring a higher operating pressure.
The dryer must never be installed where air and/or ambi-
ent temperature exceeds 120°F or drops below 50°F. Lo-
cate dryer to avoid extremes of heat and cold from ambi-
ent or other conditions. Avoid locating the dryer outside or
where exposed to the elements.
8.2 LOCATING AND MOUNTING
Lift the dryer only by the lifting points indicated by the lift-
ing labels on the dryer.
Bolt the dryer to the foundation using the bolt holes provid-
ed in the base frame. Anchor bolts should project a mini-
mum of 3.5 inches above the foundation. Refer to section
12, General Arrangement Drawings, for details.
8.3 PIPING
Pipe the compressed air lines to the inlet and outlet con-
nections. Locate the prefilters as close as possible to the
dryer. Ensure the positioning allows for ease of servicing.
Refer to the General Arrangement drawing.
Note that the wet air inlet is at the dryer’s lower manifold,
while the dry air outlet is at the dryer’s upper manifold.
In situations where air supply is required 24 hours a day
(where it is undesirable to interrupt the airflow), a three
valve by-pass system is recommended to bypass the
dryer. Use the fewest elbows necessary to keep pressure
drop at a minimum.
Once all piping has been connected, all joints, including
those on the dryer, should be soap bubble tested at line
pressure to ensure no joints have been damaged in transit
and during site placement. All installed piping must be
self-supported.
8.4 FILTRATION
It is important that a prefilter and an afterfilter be provided
in your dryer installation.
Coalescing prefilters, located before the dryer, protect
desiccant beds from contamination by oil, entrained wa-
ter, pipe scale, etc., thereby, extending dryer desiccant life.
Locate prefilters as close to dryer as possible.
It is recommended that a mechanical separator be in-
stalled immediately preceding the prefilter to remove bulk
liquid and entrained water.
Particulate afterfilters, located after the dryer, help elimi-
nate the possibility of desiccant dust carryover into the air
system.
8.5 ELECTRICAL CONNECTION
Make all electrical connections to the dryer as shown on
the wiring diagram. Care must be taken to connect the
proper voltages.
Size field connection knock-out for the conduit fitting re-
quired by the NEC.
8.0 INSTALLATION AND START-UP
!NOTICE
The standard dryer is not rated for any gas other than
air.
!NOTICE
ZEKS recommends the mufflers be cleaned after initial
start-up to remove any desiccant dust generated during
dryer shipment.After running the dryer for the initial 30 min-
ute period, de-energize/depressurize the dryer and remove
the mufflers. Disassemble and clean the removable insert
inside the muffler core. Reinstall the mufflers prior to oper-
ating dryer.
!NOTICE
All ZPA dryers must have proper filtration. Liquid water
and oil must be removed before compressed air enters
the dryer. Ensure separators, prefilters and drains are
in good working order. Failure to do so will void war-
ranty.
!NOTICE
Dryer must be grounded with the full size ground wire
connected to an earth ground.
!NOTICE
Dryer must be fused according to NEC with the size fuse
listed on the dryer serial nameplate, or on specification
sheet in Technical Manual.
ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
8

8.0 INSTALLATION AND START-UP
8.6 DESICCANT LEVEL VERIFICATION
Remove desiccant fill port at the top of each vessel (tower)
and check desiccant level. The level should be consistent
with the level depicted on the Desiccant Fill Chart on page
12 of this Technical Manual.
8.7 START-UP
• Slowly pressurize the dryer. When the dryer reaches full
operating pressure, check the system for air leaks. Soap
test all joints and fitting. To maintain desired dew point,
any leaks detected must be fixed, especially those on the
outlet side of the dryer.
• Make sure that the purge adjustment valve is open and
air outlet shut off valve (if equipped) is closed.
• For dryers equipped with a dew point monitor, remove
the dew point monitor sensor from the electrical enclo-
sure and install in the sensing block, located beside the
enclosure and attach the sensor cable to the sensor.
• On dryers equipped with the Moisture Load Control
(MLC) option, access the option through the DPC Con-
troller to verify that MLC is OFF to allow standard cycling
at start-up.
• Turn on dryer disconnect switch (supplied by customer)
to apply power to the dryer.
• For the first 30 seconds that the dryer is energized, both
purge valves will remain closed. After 30 seconds, the
purge valve will be opened and depressurization will oc-
cur.
• With a voltmeter, check the power connections for the
correct voltage shown on the dryer serial nameplate.
• Close and secure all electrical panel covers.
• When the dryer is energized, the Power-On Light and
Right Tower Drying Light will illuminate. When the electri-
cal circuit is energized, the Solid State Timer will start au-
tomatically. See Section 6 for logic operating sequence.
For units equipped with NEMA 4 / DPC Package, after
initialization, the On button must be pressed.
• Following depressurization of the left tower, adjust purge
valve as described in Section 6.4.
• If the dryer has been in storage or off for an extended
period of time, the Blue Moisture Indicator (BMI) may
be gray, the High Humidity Alarm (if equipped) may be
activated and the dew point display (if equipped) may
indicate a high dew point. Depending upon the duration
of idle time, it may take anywhere from one to twelve
hours for the alarm condition to clear, the BMI to return
to its normal blue color state and the dew point to drop to
design levels.
• Slowly open the outlet valve to gradually pressurize the
down stream piping.
• On dryers equipped with Moisture Load Control, the
Moisture Load Control switch may be turned “ON” to
save purge air as described in Section 7.4.
!NOTICE
For dryers equipped with the optional NEMA 4/DPC™
Package,refertotheNEMA4/DPC™PackageAppendix
in this Technical manual prior to starting dryer. !NOTICE
At initial start-up, check the dryer operation for one or
two cycles, especially at the time of the tower shift. Ver-
ify that all systems are operating in their proper order
and sequence. If the dryer is not functioning properly,
contact distributor or ZEKS Technical Service.
!NOTICE
When opening the outlet valve, insure drying tower
gaugemaintainslinepressure.Allowingpressuretodrop
in the dryer will result in an overflow condition.
!NOTICE
-80°F and -100°F dryers require flow through the dryer
to lower the pressure dew point to design levels. Failure
to permit air flow through dryer (deadheading) will re-
sult in elevated outlet dew points. Once air is permitted
to flow through the dryer, the pressure dew point will
gradually reduce to design levels.
ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 9

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
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10
9.0 MAINTENANCE AND SYSTEM CHECK
9.1 SCHEDULED MAINTENANCE
DAILY MAINTENANCE FUNCTIONS:
• Check and record inlet pressure, temperature and flow.
Verify that it is within specifications.
• Check tower pressure gauge readings within operating
tolerance.
• Check operation for proper dryer cycling, depressuriza-
tion and repressurization.
• Check that the prefilter drain is operating properly and
that there is no condensate discharged from purge muf-
flers.
• Verify that pressure in purging tower is 10 PSIG or less. If
higher, muffler replacement is recommended. See SEC-
TION 10.
• Verify that prefilter and afterfilter differential pressure is
within operating limits. Replace elements and/or cartridg-
es as required. See SECTION 9.1 Semi-Annual Mainte-
nance.
• Check the Blue Moisture Indicator. Make sure air is
bleeding through the indicator. The indicator will be blue
when air is dry.
SEMI-ANNUAL MAINTENANCE FUNCTIONS:
• Check outlet dew point.
• Check pilot air filter element and clean or replace as
required.
• Replace prefilter and afterfilter elements and/or
cartridges.
ANNUAL MAINTENANCE FUNCTIONS:
• Check desiccant and replace if necessary.
• Inspect and clean pilot air control solenoid valves, check
valves and diaphragm valves. Rebuild and / or replace
as required.
• Test lights and switches, replace as necessary.
• Test electrical components, replace as necessary.
EVERY TWO YEARS:
• Replace diaphragm and seal kits on purge and switching
diaphragm valves.
EVERY THREE-TO-FIVE YEARS:
• Rebuild purge and switching diaphragm valves (Preven-
tative).
• Replace Check Valves (Preventative).
9.2 PREFILTERS AND AFTERFILTERS
PREFILTERS - The cartridges of the prefilter must be
changed as often as required to prevent contamination of
the regenerative dryer’s desiccant bed.
The prefilter and automatic drain must be checked daily.
To prolong filter cartridge life, it is recommended that a
mechanical air / moisture separator be placed immediately
before the prefilter.
AFTERFILTERS - The purpose of the afterfilter is to re-
move residual desiccant dust. Depending upon equipment
application and usage, frequency of filter element change
will vary. It is recommended that, at the minimum, the filter
element be changed every six months.
9.3 PILOT AIR CONTROL SOLENOID VALVES
The length of time the pilot air valves can reliably oper-
ate without replacement is dependent upon the type of
dryer and the dryer’s operation. On ZEKS -40°F dewpoint
dryers, replacing the valves every 60 months is recom-
mended. Given the difference in cycle times for -80°F and
-100°F units, these dryers should have their pilot valves
replaced every 30 months.
PILOT AIR FILTER ELEMENT IDENTIFICATION AND
REPLACEMENT
To determine the correct replacement element for the
Pilot Air Filter on the dryer, visually identify the filter that
is mounted on the right side of the Electrical Enclosure
and compare it to the options shown below. Select the
replacement element that matches the Pilot Air Filter and
use the corresponding Part Number when ordering.
!NOTICE
Should the drying system be overloaded and/or
malfunctioning, causing high pressure drop, afterfilters
may prematurely plug. This problem can be avoided
by frequent inspection and proactive replacement of
cartridges.
Use Replacement Element
Part No.: E15H Use Replacement Element Part No.: 104424

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 11
9.0 MAINTENANCE AND SYSTEM CHECK
9.4 MUFFLER CHANGEOUT PROCEDURE
• Depressurize the dryer turn control power off.
• Replace muffler.
• Follow Start-up procedure described in SECTION 8.7.
• Turn control power back on.
9.5 PURGE AND SWITCHING DIAPHRAGM VALVES
These valves have two control ports; one on top and the
other on the back side.
• Normally Open (N.O.) Valves: For N.O. inlet or repres-
surization valves, control air is supplied to the top port.
The back side port exhausts out the bottom side of the
diaphragm. If air leaks continuously when control air is
supplied to the valve, the internal seals are leaking and
must be replaced.
• Normally Closed (N.C.) Valves: For N.C. purge valves,
the top port is plugged. Control air is supplied to the back
port. If air vents out of the back port continuously when
the solenoid is de-energized, it will exhaust through the
top of the solenoid. If this condition is observed, the inter-
nal seals are leaking and must be replaced.
9.6 OUTLET CHECK VALVES
Outlet check valves sealing can be verified by depressur-
izing the dryer and slowly applying pressure to the outlet.
The valves should seal and prevent air from pressurizing
the towers. If a tower begins to pressurize, the check valve
on that side requires replacement.
9.7 DESICCANT CHANGEOUT PROCEDURE
When it becomes necessary to replace the desiccant in
the towers, or on units that are shipped without the desic-
cant installed, observe the following procedure:
• The standard units are furnished with fill and drain ports
oneach desiccanttower. Remove thecaps onboth ports.
• To assist in getting the desiccant to flow from the tower,
insert a small rod into the drain port as necessary. This
may be required as the desiccant is packed into the tow-
ers which may interfere with the desiccant flow from the
towers.
• Retainer screens, located at the inlet and outlet piping
connections of the tower, are removable on all models. It
issuggested that these screens be removed and cleaned
at the time of desiccant changeout. These screens can
be accessed by disconnecting the upper and lower mani-
folds from the dryer towers.
• After cleaning the retainer screens, replace screens and
reattach the outlet port plug.
• With the fill port plug removed, fill the dryer tower with the
appropriate grade and size desiccant. For those dryers
that are shipped without desiccant installed, using the fill
kit provided with the dryer will facilitate filling the desic-
cant in the tower. The level of the desiccant should be
below the top retainer screen as shown on the Desiccant
Fill Chart on the following page.
• Once the towers have been filled, replace the fill port plug
on each tower.
• Any connections disturbed in the desiccant changeout
process should be leak tested prior to re-commissioning
the dryer.
!WARNING
To avoid injury, depressurize dryer before performing
any service.
!CAUTION
Desiccant will produce dust during the changeout pro-
cedure. Be sure to wear respiratory protection during
the draining and filling process to minimize inhalation of
desiccant dust.
!WARNING
To avoid injury, depressurize dryer before performing
any service.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
12
9.0 MAINTENANCE AND SYSTEM CHECK
(AA) (AA) (MS)
DIMENSIONS (INCH) -40oF -100oF
MODEL DRYERS DRYERS
A B C lbs./Dryer lbs./Dryer
90 23.00 10.50 30.00 100 75 25
120 17.00 6.50 20.38 134 101 34
160 22.00 8.50 28.75 192 144 48
200 14.00 3.00 21.50 236 177 59
250 23.00 10.50 28.00 290 218 73
300 12.00 6.00 21.25 344 258 86
400 11.00 6.00 22.25 470 353 118
500 27.00 12.75 34.75 638 479 160
600 17.50 7.75 29.00 748 561 187
800 34.00 13.50 41.00 900 675 225
1000 23.00 7.50 31.50 1100 825 275
1200 10.00 2.00 23.75 1270 953 318
1500 12.00 2.75 23.25 1600 1200 400
1800 35.00 15.50 45.75 2000 1500 500
2100 22.00 10.75 38.50 2340 1755 585
2700 6.00 2.50 26.00 2928 2196 732
3300 16.25 8.00 35.25 4000 3000 1000
4000 7.75 3.50 29.00 4250 3150 1100
5000 9.00 4.25 28.00 5600 4200 1400
ACTIVATED ALUMINA (AA); 4-8 mm ACTIVATED ALUMINA (AA); 4-8 mm
MOLECULAR SIEVE (MS)
-40oF DRYERS -100oF DRYERS
NOTE: Desiccant weight shown is per-dryer.
DESICCANT FILL INSTRUCTIONS

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 13
10.0 TROUBLESHOOTING
PROBLEM
Elevated dew point
Blue Moisture Indicater (BMI)
indicates high moisture level.
Excessive pressure drop in
dryer
Failure to shift
Dryer fails to pressurize.
Dryer depressurizes too
rapidly.
Dryer fails to purge.
Excessive back pressure in
regenerating tower (above 5
psig).
Right tower excessively high
pressure at the purge gauge.
PROBABLE CAUSE
Insufficient purge rate.
Inlet air pressure below design condition.
Flow rate higher than design condition.
Inlet temperature above design condition (120F).
Entrained water entering desiccant bed.
Desiccant contaminated by oil.
Elevated dew point.
BMI wet.
Excessive flow rate.
Inlet pressure below design condition.
No input power.
Defective solenoid valve.
No pilot air.
Pilot-operated diaphragm valve seat failure.
Faulty purge valve.
Purge valve does not close; dryer repressurizing
through inlet valve.
Purge valve does not open. Purge valve stuck in
closed position.
Purge muffler does not pass air.
Purge muffler passes too much air. Air is leaking
across valve.
Improper calibration.
CORRECTIVE ACTION
Check purge flow settings.
Check purge piping for obstruction.
Clean purge piping and muffler.
Check pressure source and system for leakage.
Check flow rate and cause for increased demand.
Correct flow rate condition.
Check aftercooler. Clean and service as necessary.
Check air/moisture separator, prefilter and drains.
Replace dryer desiccant if necessary.
Install suitable prefilter. Replace dryer desiccant.
Refer to “Elevated Dew Point” corrective actions
shown above.
Depending on degree of saturation of the desic-
cant, the BMI may take a week or more of con-
tinuous use to switch back to its blue (dry) state.
Check flow rate and cause for increased air demand.
Check pressure source.
Check power input.
Check solenoid valve.
Check pilot air line. Check that control air line
filter is clean.
Inspect seals and replace as required.
Check that repressurization circuit is sending
control signal.
Check purge valve and its solenoid valve.
Check purge valve and its solenoid valve.
Check purge valve and its solenoid valve. Repair
and replace if necessary.
Check that repressurization circuit is sending
control signal.
Purge muffler is dirty; replace.
Check inlet valve and outlet check valves. Verify
inlet valve is closed to purging tower (0 psig
tower).
Reset when right tower is online.
For troubleshooting procedures, refer to maintenance descriptions in Section 9 as required.

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
14
11.0 PURGE CHARTS
0
2
4
6
8
10
12
14
16
18
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 9/64"
90ZPA Setting - 48 psig @ 14 SCFM
0
2
4
6
8
10
12
14
16
18
20
22
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 5/32"
120ZPA Setting - 53 psig @ 19 SCFM
0
5
10
15
20
25
30
35
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 3/16"
160ZPA Setting - 50 psig @ 26 SCFM
0
5
10
15
20
25
30
35
40
45
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 7/32"
200ZPA Setting - 42 psig @ 30 SCFM
0
5
10
15
20
25
30
35
40
45
50
55
60
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 1/4"
250ZPA Setting - 42 psig @ 40 SCFM
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 9/32"
300ZPA
Setting - 40 psig @ 48 SCFM

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 15
11.0 PURGE CHARTS
0
10
20
30
40
50
60
70
80
90
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 5/16"
400ZPA
Setting - 45 psig @ 65 SCFM
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 3/8"
500ZPA
Setting - 35 psig @ 81 SCFM
0
10
20
30
40
50
60
70
80
90
100
110
120
130
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 3/8"
600ZPA
Setting - 41 psig @ 93 SCFM
0
20
40
60
80
100
120
140
160
180
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 7/16"
800ZPA
Setting - 46 psig @ 130 SCFM
0
20
40
60
80
100
120
140
160
180
200
220
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 1/2"
1000ZPA Setting - 43 psig @ 162 SCFM
0
30
60
90
120
150
180
210
240
270
300
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 9/16"
1200ZPA
Setting - 41 psig @ 195 SCFM

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
16
11.0 PURGE CHARTS
0
30
60
90
120
150
180
210
240
270
300
330
360
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 5/8"
1500ZPA
Setting - 41 psig @ 243 SCFM
0
30
60
90
120
150
180
210
240
270
300
330
360
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 5/8"
1800ZPA
Setting - 51 psig @ 292 SCFM
0
50
100
150
200
250
300
350
400
450
500
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 3/4"
2100ZPA Setting - 40 psig @ 340 SCFM
0
50
100
150
200
250
300
350
400
450
500
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 3/4"
2700ZPA
Setting - 53 psig @ 438 SCFM
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 7/8"
3300ZPA
Setting - 47 psig @ 535 SCFM
0
100
200
300
400
500
600
700
800
900
1000
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 1"
4000ZPA
Setting - 44 psig @ 649 SCFM

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 17
11.0 PURGE CHARTS
0
100
200
300
400
500
600
700
800
900
1000
0 10203040506070
Purge Air Flow - SCFM
Purge Meter Setting - psig
Purge Orifice - 1"
5000ZPA
Setting - 56 psig @ 811 SCFM

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com
18
12.0 GENERAL ARRANGEMENT

ZEKS Eclipse ZPA 90-5000 Desiccant Dryers
www.zeks.com 19
12.0 GENERAL ARRANGEMENT