Stulz DesicAir 1000 Series User manual

STULZ Desicair
DEZ Series 1000
Desiccant Dehumidification System
Installation, Operation and Maintenance Manual

MODEL NOMENCLATURE
DESICAiR Product Identification Number Example
DEZ –600 – 40– E
DEZ = Desicair Series 1000
Nominal Process Airflow
150 CFM
300 CFM
450 CFM
600 CFM
Reactivation Type
E =Electric
Rotor Diameter
35 cm
40 cm
Notice
This document contains information protected by copyright. All rights are reserved. The owner of the equipment for which
this manual is written may photocopy the contents of this manual for internal use only. No part of this document may be
photocopied, reproduced, or translated into another language for use by anyone other than the owner of the equipment for
which this manual is written without the prior written consent of Stulz Air Technology Systems, Inc. (STULZ).
This document contains STULZ confidential and proprietary information. Distributing or photocopying this document for
external distribution is in direct violation of U.S. copyright laws and is strictly prohibited without the express written
consent of STULZ.
Unpublished — rights reserved under the copyright laws of theUnited States and of other countries. Other
brands and tradenames are trademarks of their respectiveowners.
Copyright 2017 by Stulz Air Technology Systems, Inc.
Printed in the United States of America.
All rights reserved.
Stulz Air Technology Systems, Inc.
1572 Tilco Drive
Frederick, MD 21704
USA

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
i
Table of Contents
1.0 GENERAL INFORMATION ........................ 1
1.1 About this Manual ....................................... 1
1.2 Introduction ................................................. 1
1.2.1 Technical Data Package.......................... 1
1.2.2 Dehumidifier Identification Number ......... 1
1.2.3 Unit Nameplate ........................................ 3
1.3 Safety .......................................................... 3
1.3.1 Warnings and Cautions ........................... 3
1.4 Theory of Operation .................................... 4
1.5 Construction ................................................ 5
1.5.1 Design Features ...................................... 5
1.5.2 Cabinet..................................................... 5
1.5.3 Inlets and Outlets..................................... 6
2.0 INSTALLATION.......................................... 7
2.1 Receipt of Unit............................................. 7
2.2 Rigging ........................................................ 7
2.3 System Location and Clearance................. 7
2.4 Connecting Ductwork.................................. 7
2.5 Utility Connections ...................................... 8
2.6 Installing a Humidistat or Relative Humidity
Transmitter .................................................. 8
3.0 OPERATION............................................... 9
3.1 Installation Checks ...................................... 9
3.2 Start Up ....................................................... 9
3.3 Reactivation Heater Controller.................. 10
3.4 Capacity Control ....................................... 10
3.4.1 D-Stat..................................................... 10
3.4.2 H-Trac .................................................... 10
3.4.3 Dew-Trac ............................................... 10
3.4.4 C-Trol II.................................................. 10
3.4.5 Proportional Reactivation Controls
(H-Trac or Dew-Trac)............................. 11
3.5 Control Panel ............................................ 11
3.5.1 Mode Selector Switch ............................ 12
3.5.2 Hour Meter............................................. 12
3.5.3 Control Panel Lights .............................. 12
3.5.4 Optional Fault Indication Lights ............. 12
3.6 Monitoring Unit Performance .................... 13
4.0 UNIT FEATURES ..................................... 14
4.1 Control Sensor Terminals ......................... 14
4.2 Remote Start/Stop Contact ....................... 14
4.3 Optional Customer Contacts..................... 14
4.4 Sensor Retransmit Terminals ................... 14
4.5 Electrical Disconnect................................. 14
4.6 Emergency Stop ....................................... 15
4.7 Dampers.................................................... 15
4.8 Filter Status ............................................... 15
4.9 Voltage Sensor/Phase Monitor ................. 15
4.10 Process Air Proving .................................. 15
4.11 E2 Controller and Display ......................... 15
5.0 PREVENTIVE MAINTENANCE ................ 16
5.1 Monthly ......................................................16
5.2 Yearly......................................................... 16
5.3 Desiccant Rotor Drive Motor Maintenance16
5.4 Blower Motor Maintenance........................ 16
5.4.1 General Inspection ................................. 16
5.4.2 Lubrication & Bearings ...........................17
5.4.3 Lubrication Procedure ............................18
6.0 TROUBLESHOOTING .............................. 19
7.0 REPAIR PROCEDURES........................... 21
7.1 Rotor Handling Guidelines.........................21
7.2 Replacing the Rotor Drive Belt .................. 21
7.2.1 Removing the Old Belt ...........................22
7.2.2 Installing the New Belt............................ 22
7.3 Removing the Rotor................................... 22
7.4 Replacing Seals.........................................22
7.4.1 Removing Old Seals...............................22
7.4.2 Installing New Seals ............................... 23
7.5 Washing the Rotor.....................................23
7.5.1 Cleaning .................................................23
7.6 Repairing the Rotor ...................................23
8.0 PRODUCT SUPPORT .............................. 25
8.1 Technical Support...................................... 25
8.2 Obtaining Warranty Parts .......................... 25
8.3 Obtaining Spare/Replacement Parts.........25
Appendix A
Installation Checklist ........................................ A-1
Maintenance & Service Checklist .................... A-2
Appendix B
Unit Performance Curves ................................ B-1
Appendix C
Glossary........................................................... C-1

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
ii
Figures
Figure 1 - Sample Nameplate............................................3
Figure 2 - General Theory of Operation Diagram..............5
Figure 3 - Locating a Wall Mounted Control Sensor..........8
Figure 4 - Proportional (Trac) Control Diagram ...............11
Figure 5 - Sample Non-E2Control Panel Layout.............12
Figure 6 - Sample E2Control Panel Layout.....................12
Figure 7 - Differential Pressure Gauges ..........................13
Figure 8 - E2Controller and Display ................................15
Figure 9 - Overheat Safety Switch...................................19
Figure 10 - Rotor Assembly Parts ...................................22
Figure 11 - Rotor Scratch Repair.....................................24
Tables
Table 1 - Blower Motor Lubrication Intervals ...................17
Table 2 - Service Conditions............................................17
Table 3 - Lubrication Interval Multiplier............................17
Table 4 - Bearing Sizes and Types .................................18

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
1
1.0 GENERAL INFORMATION
1.1 About this Manual
This manual provides installation, operation, and
maintenance information for the STULZ DESICAiR®
DEZ Series 1000 dehumidification system. The DEZ
system has several standard options which are
covered in this manual. The exact configuration of
your system is reflected in the Engineering drawings
provided in the Technical Data Package shipped with
your system. It is also described in the Dehumidifier
Identification Number (DIN) sheet and other submittal
package documents for your system. You can use
these documents to determine the sections of this
manual that are relevant to your system.
1.2 Introduction
The DEZ Series 1000 dehumidification system is
designed and manufactured by Stulz Air Technology
Systems, Inc. (STULZ) utilizing the latest, state-of-the-
art control technology. Recognized as a world leader,
STULZ provides dehumidification systems
manufactured with the highest quality craftsmanship
and materials. The unit will provide years of trouble
free service if it is installed, operated and maintained
as described in this manual. Damage to the unit from
improper installation, operation or maintenance is not
covered by the warranty.
Study the instructions in this manual; they must be
followed to avoid difficulties. Spare parts are available
from STULZ to ensure continuous operation. Using
substitute parts or bypassing electrical or other
components in order to continue operation is not
recommended and will void the warranty.
1.2.1 Technical Data Package
This manual is part of the Technical Data Package
provided with your unit. The Technical Data Package
typically includes drawings, Technical Data Sheets, a
Flow Diagram, a Test Report and component part
manufacturer’s manuals containing additional
information about significant components. The
Technical Data Package may also contain related
STULZ manuals (for example, a system controller
manual). These documents should be stored in a safe
place on or near the unit for reference.
A Warranty Registration and Start-up Checklist form is
also included in the Technical Data Package. This
form must be completed during installation and
returned to STULZ Product Support to activate your
warranty.
1.2.2 Dehumidifier Identification Number
The Dehumidifier Identification Number (DIN) defines
specific features that are provided with your unit (see
section 1.2.2.1). The DIN Sheet for this unit is
included for reference in the unit Technical Data
Package. The Technical Data Package also contains
a technical data sheet, a test report (showing
performance information), drawings and this manual.
A manual for the system controller is also provided
under separate cover. These documents should be
stored in a safe place on or near the unit for
reference.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
2
1.2.2.1 Dehumidifier Identification Number (DIN) Sheet
The DIN starts with the model number. The DEZ model number includes the nominal process CFM followed by the
desiccant rotor diameter. (ex: DEZ-600-40). The first 15 digits after the model number (represented by the uppercase
letters A–N below) pertain to the cabinet construction, rotor type, and process and reactivation accessories or
options.
Process CFM Rotor Diameter in Centimeters
DEZ- XXX - XX - AA - B C D E F G H - I J K - L M N
Model Reactivation Cabinet Construction Process Reactivation
Number Type and Rotor Accessories Accessories
The last 17 digits (represented by the lowercase letters a-n below) pertain to the electrical system, unit controls,
control scheme and control panel features.
aa b c - dd ee - f g h i - j k l m n
Power and Capacity Status Other
Wiring Control Contacts
The following is a sample DIN Sheet for a DESICAiR DEZ Series 1000 Desiccant Dehumidifier:

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
3
1.2.3 Unit Nameplate
The Unit Nameplate, located on the front or side of
the unit, is a quick source for useful information
about your system, such as the unit model number,
serial number and specific STULZ job number (see
Figure 1 for an example). This data will be required
if you contact STULZ for assistance, warranty
information, or spare parts. The Unit Nameplate
also includes the process and reactivation airflow
targets, along with their corresponding rotor
pressure drops.
Figure 1 - Sample Nameplate
1.3 Safety
Read and understand all instructions,
recommendations, and guidelines in this manual
regarding the installation, maintenance, and
operation of this unit prior to installation and start-
up. All maintenance and repairs should be
conducted by personnel thoroughly trained in the
operation and maintenance of this or like equipment.
The main power supply to the equipment must be shut
off before beginning work on the equipment. Take
extreme care to ensure that every capacitor likely to
hold electrical charge has been grounded. Always
remove all rings, watches, and other jewelry when
working on electrical equipment. Some of the
equipment used may present the hazard of
Electrostatic Discharge (ESD). When working inside
the equipment, always ground all parts before
touching. When working on or near ESD-sensitive
components, use a wrist grounding strap if possible.
Never operate the unit with any cover, screen, guard,
panel, etc., removed unless the instructions
specifically state to do so, and then do so with
extreme caution to avoid personal injury. Never
attempt to lift any component in excess of 35 pounds
without additional help.
Placards and/or stickers have been placed in various
locations on or in the unit. These placards/stickers are
intended to call attention to personal safety and
equipment damage hazards.
Certain maintenance and cleaning procedures may
either recommend or specify the use of solvents,
chemicals, or cleansers. Always refer to the
manufacturer’s Safety Data Sheet (SDS) prior to
handling any of these materials.
1.3.1 Warnings and Cautions
The following is a condensed list of warnings and
cautions that are noted throughout this manual. All
personnel who operate, service and maintain this
equipment should read and understand these
warnings and cautions. All warnings indicate a
potential threat to personnel and all cautions indicate
a potential threat to equipment damage.
Prior to using any chemicals, cleansers, or solvents,
refer to the manufacturers Safety Data Sheets (SDS)
for proper handling and usage of such materials.
Voltages used with this unit can
be deadly. Be careful not to contact high AC
voltage connections when installing or operating
this equipment. Use the services of a qualified
electrician and/or technician to make the electrical
power connections and perform maintenance.
Disconnect main power to the unit
before performing any maintenance or service.
Turning the mode selector switch to the Off
position does not disconnect power to controls or
the unit itself.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
4
Whenever the nature of the
operation permits, keep one hand away from
the equipment to reduce the hazard of current
flowing through vital organs of the body.
Never work on electrical
equipment unless there is someone nearby
who is both familiar with the operation and
hazards of the equipment and competent to
administer first aid. When operators aid the
technician, the technician must warn them
about dangerous areas.
Do not be misled by the term
"low voltage" which may appear in this manual
or on drawings or documents in the Technical
Data Package. Electrical voltages as low as 50
volts can cause death under certain conditions.
Multiple power sources may be
used in the unit. Ensure power is disconnected
from all sources before servicing powered
components.
Do not touch hot system
components. The design reactivation
temperature range is 250–300 °F. The
components of the reactivation system may be
extremely hot during operation. Be absolutely
certain that the unit and/or reactivation
components are cool before attempting to work
on or near them.
Unless otherwise specifically
instructed, do not operate the equipment
without all grilles, guards, louvers and covers
in place and tightly secured. When instructed
to operate without a grille, guard, louver or
cover in place, do so with care.
Blower motors may start
unexpectedly when the unit is running due to
an automatic resetting of the internal overload
device.
Do not allow anyone under the
equipment while it’s suspended from a lifting
device.
Do not allow the unit to swing
while suspended from a lifting device. Failure
to observe this warning may result in injury to
personnel and damage to the equipment.
!
CAUTION
Ensure that the dehumidifier is
properly phased. Improper phasing can cause severe
damage to the equipment.
!
CAUTION
Air intake and discharge openings
must be completely free of obstructions. Ensure
panels are on and properly secured into position.
!
CAUTION
Do not operate the unit without
filters. It is better to operate the unit with dirty filters
than no filters. Operating the unit without filters may
void the warranty.
1.4 Theory of Operation
The DEZ Series 1000 dehumidification system is
designed to dehumidify a space to a level below that
attainable with a refrigeration-based dehumidification
system. Moisture is removed from the air by being
passed through a desiccant wheel (called the “rotor”)
that is impregnated with a dry desiccant. Process air
(the air being dehumidified) is filtered, dehumidified
and supplied to a conditioned space at a lower relative
humidity and a slightly higher dry bulb temperature
than its inlet condition.
Simultaneously, a second airstream (reactivation air)
is filtered and heated by a reactivation heater system,
then passed through a separate segment of the rotor.
This heated reactivation air removes the previously
adsorbed moisture from the desiccant rotor and
exhausts it to an area other than that being
conditioned. During operation, the desiccant rotor
rotates through the process and reactivation
airstreams of the dehumidifier at a constant speed.
The two airstreams are separated by face and
peripheral seals and by internal fluting in the desiccant
rotor. Process and reactivation airstreams are
counter-flow to maximize the efficiency of the
adsorption process and to help prevent the rotor's
flutes from fouling.
The reactivation heater is sized to raise the
temperature of the reactivation air entering the
desiccant rotor approximately 180 ºF above ambient
(depending upon moisture adsorbed from the process
air and reactivation airflows). The energy from the
heated reactivation air is used to desorb the moisture.
Reactivation discharge air temperature will vary and
can be as high as 150 ºF and moist. Controls are
included in the unit to vary reactivation heat based
upon the amount of moisture adsorbed from the
process airstream.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
5
Electric heat is generated by a heater controlled by
an SSR (solid state relay) or SCR (silicon
controlled rectifier). The SSR cycles the heater on
and off based on signals received from the system
controller to maintain the reactivation discharge air
temperature. An SCR also receives controller
signals, but modulates the percentage of heater
output energy (as opposed to turning the heater on
and off) for tighter temperature control.
There may be more than one heater bank
depending upon the output required. Refer to the
Electrical drawing and technical data sheet for more
detail.
NOTE: The reactivation air temperatures mentioned in
the preceding discussion may vary between DEZ
systems. See the Technical Data Sheet for your unit
for target temperatures.
Figure 2 - General Theory of Operation Diagram
1.5 Construction
This desiccant dehumidifier was manufactured by
STULZ and has passed all Quality Control checks,
including a complete functional testing. Every effort
has been made to ensure the dehumidification system
will perform satisfactorily for many years.
1.5.1 Design Features
Rugged All-Aluminum Cabinet
Continuous or Automatic Operation
Inert, Stable Silica Gel Desiccant
Non-toxic, Non-corrosive Desiccant
Capable of Withstanding 100% RH Without
Adverse Effect
Counterflow Process and Reactivation Air
Patterns
Overheat Safety Protection
Electric Reactivation Heat
Easy Access to Internal Components
Low Operating Cost, Energy Efficient
Dehumidification
Optional Process and Reactivation Inlet Air Filters
For a comprehensive list of the features included,
refer to the DIN Sheet provided specifically for this
unit. The DIN sheet is a listing of all the standard and
optional features that are included (see section 1.2.2).
For particular detail of the features, refer to the
drawings provided with this unit.
1.5.2 Cabinet
This unit is self-contained in an aluminum cabinet
rated for either indoor or outdoor use (see Unit
Nameplate). The exterior of the cabinet is finished
with a durable paint to protect it against corrosion.
Removable access panels are provided for easy
access to all major components for maintenance
and/or service.
The operator controls are conveniently located in the
front of the unit (see the installation drawing provided).
The cabinet houses the desiccant rotor assembly and
drive system, process and reactivation air blowers, a
Process
Air Outlet
Process
75% of rotor
Reactivation
25% of rotor
Desiccant
Rotor
Process
Air Inlet
Reactivation
Air Outlet
Process
Air Filter
Reactivation
Air Blower
Process
Air Blower
Reactivation
Air Filter
Reactivation
Heater(s)
Reactivation
Air Inlet

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
6
reactivation heater system (electric), and electrical
controls.
1.5.3 Inlets and Outlets
Inlets and outlets may be provided with flanged duct
connections or with duct connections for round hard or
round flexible duct. Depending on whether the unit is
intended for indoor or outdoor use, the process and
reactivation inlets and outlets may be equipped with
louvers or hoods to prevent rain and snow from
entering the unit. Screens may be provided to prevent
birds and other small animals from nesting in the
inlets and outlets.
For a comprehensive list of the features, refer to the
DIN sheet provided specifically for this unit (see
section 1.2.2). The DIN sheet is a listing of all the
optional features that are included. For particular
detail of the features, refer to the Installation drawing
provided for this unit.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
7
2.0 INSTALLATION
2.1 Receipt of Unit
Upon receiving the desiccant dehumidification unit,
immediately inspect the equipment for damage which
may have occurred during shipment. If any is found,
report it to the carrier immediately. Any obvious
damage incurred during shipping must be noted on
the freight carrier’s delivery forms before signing for
the equipment. Freight claims must be made through
the freight carrier. Generally, all equipment ships
F.O.B. Factory. STULZ can assist in the claim filing
process with the freight company.
Carefully remove the shipping materials and
protective packaging. Remove/open the access
panels, remove any loose parts, and check the
equipment against the packing list to see if the
shipment is complete. Report all discrepancies to the
appropriate authority.
2.2 Rigging
The dehumidifier is designed to be kept in a vertical
position. Move the unit with a suitable device, such as
a forklift, or attach an overhead lifting sling to the unit,
supporting it from beneath the mounting base.
If an overhead lifting device is used, use one with the
appropriate capacity to ensure it can safely handle the
weight of the unit. If using an overhead lifting device,
utilize spreader bars that exceed the cabinet width to
avoid crushing the sides of the unit and/or damaging
components mounted to the sides.
Do not allow the unit to swing
while suspended from a lifting device. Failure to
observe this warning may result in injury and
damage to the equipment.
2.3 System Location and Clearance
Allow unrestricted access to the dehumidifier to
perform routine inspection and maintenance.
Recommended minimum clearance on at least one
side of the unit is the full width of the unit plus space
for necessary equipment, (forklift, lifting device, etc.).
Refer to local and national electric codes for additional
working clearance requirements.
To judge the clearance requirements, consider that of
the components housed inside the dehumidifier
cabinet, the desiccant rotor is typically the largest
component requiring removal, although blower
assemblies, while somewhat smaller, also require
sufficient clearance for removal.
The leaving reactivation air can
be very warm and humid. Keep items that may be
damaged by excessive heat and humidity away
from the reactivation air outlet.
Position the unit in the desired location. Make sure
the mounting surface is able to support the weight of
the equipment and keep it level. Secure the unit to the
mounting surface. Mounting holes may be drilled into
the base of the unit to anchor it. The following general
requirements should also be considered:
1. The main power disconnect should be located
as near as possible to the installed location of
the equipment.
2. Provisions should be made to ensure that power
is not accidently disconnected during normal
operation and that the disconnect switch is not
used to turn off the unit for normal shut-down.
3. If possible, avoid locations where the air intakes
will be laden with dust, dirt, soot, smoke, or
other debris.
4. Do not operate unit in or near flammable or
corrosive environments or allow flammable or
corrosive air into the unit.
5. Refer to the wiring diagram for electrical
connections.
2.4 Connecting Ductwork
All ducting must be airtight or the dehumidification
system will not perform to maximum capability. Even
small leaks can have a dramatic effect on system
performance. Ducting should be sized for the
appropriate airflow and pressure drop. The clearance
required for the connection depends on whether the
unit is to have ducts attached for the process air,
reactivation air, or both. The reactivation air
temperature at the outlet will be warm (approximately
150 °F) and humid during normal operation.
(Reactivation air may approach 180 °F during a fault
condition.)
When installing a unit in the conditioned space, the
reactivation inlet and outlet must be ducted to and
from another area to prevent warm, moist air from
returning to the conditioned space. If ductwork is
connected to the reactivation outlet, it should be
insulated and sloped down and away from the unit.
This prevents condensed moisture from accumulating
at the reactivation outlet.
When installing a unit outside the conditioned space,
the process inlet and outlet must be ducted to and
from the conditioned space to prevent humid air from
entering the process airstream. Refer to the

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
8
installation drawing for the duct connection sizes and
locations.
NOTE: A flow regulation damper is required but may
not be provided in the process air outlet. In such
cases, it is the responsibility of the contractor or the
owner to install a flow regulation damper. Adjust the
regulating dampers after all ductwork is installed.
Refer to section 3.6, “Monitoring Unit Performance,”
for more information concerning setting the correct
airflows. If the process airflow is not set correctly, unit
performance may be adversely affected. Refer to the
Unit Nameplate for the correct air volume.
Ensure that inlets and outlets are free of obstructions
and filters are clean.
2.5 Utility Connections
High voltage is used in the
operation of this unit. Use the services of a
qualified electrician only to make the electrical
power connections.
1. Refer to the electrical drawing for the main
power connections.
2. Connect power to TB1 or the main disconnect
per the electrical drawing for this unit. See the
Unit Nameplate (mounted near the electrical
control box) for the operating power supply
requirements, minimum circuit ampacity (MCA)
and maximum fuse size (MFS).
2.6 Installing a Humidistat or Relative
Humidity Transmitter
A terminal block is provided for the connection of a
humidistat or temperature/RH sensor. Interconnecting
field wiring must be installed in accordance with NFPA
70 of the National Electrical Code (N.E.C.). Refer to
the electrical drawing for the electrical connections.
Wall-mounted control sensors should typically be
mounted 4–5 feet up from the floor in the conditioned
space (see Figure 3). The sensor must be located so
that it will properly sense the conditions to be
controlled. The sensor should not be mounted in an
open doorway or an area where it will be exposed to
direct sunlight.
Locate the sensor according to the application. To
control the conditions in a space, a wall mounted
sensor may be used in the space or a duct mounted
sensor may be located in the return air inlet duct if the
air is re-circulated. To control the air supplying a
process, a duct mounted sensor may be located in the
supply air duct near the process. Duct mounted
sensors cannot be used for D-Stat control but can be
used if the unit is configured for control schemes
where the process blower runs continuously such as
D-Stat II or H-Trac control (see section 3.4, Capacity
Control).
Figure 3 - Locating a Wall Mounted Control Sensor
Mount the sensor in the center of the
room where air circulation is
g
ood.
4-5 ft.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
9
3.0 OPERATION
The following information provides an overview of
operating procedures and sequences for the DEZ
unit. Before operating the unit, go through the
checklist below to make sure all electrical and
utility connections are correct and that the unit is
ready for operation.
NOTE: A Warranty Registration and Start-Up
Checklist are provided in the Technical Data
Package supplied with your unit. It must be
completed during installation and sent to STULZ
Product Support. It will assist if service or
troubleshooting support is needed. See section 8.0
for contact information.
3.1 Installation Checks
Using the Warranty Registration and Start-Up
Checklist forms, record the steps taken during
installation. Recommended tools for performing
the pre-operation checkout include a voltage
meter with temperature probe, a flashlight, a
Phillips and flathead screwdriver, and a digital
amp meter.
1. Verify the main power is correct per the Unit
Nameplate. Only use power that’s rated for
this unit per the Unit Nameplate. Incorrect
power may damage the unit and cause
damage to property or injury or death to
personnel.
2. Check the wiring to any remote sensors,
humidistats, start/stop devices, etc. Refer to
the electrical drawing for specific wiring
connections.
3. Check all electrical connections for
tightness.
4. Be sure there are no loose parts or spare
parts (such as extra filters, etc.) located
inside the unit or electric box.
5. Be sure all access panels or doors are
closed tight. Small air leaks can significantly
reduce unit performance.
3.2 Start Up
1. Apply main power to the unit and turn the
mode selector switch to On. Check that the
rotation of all motors, (process, reactivation,
and rotor drive motor), are as indicated by
the arrow labels.
2. Set airflows to the required rotor pressure
drop versus the airflow required for this
application. Airflow is indicated by rotor
pressure drop values as viewed on the
differential pressure gauges. The Unit
Nameplate shows the optimum
“Reactivation Side” and “Process Side”
pressure drops (labeled as “Rotor Pressure
Drop Gauge Values” with values shown as
in. w.g.). Process airflow is set using an
airflow damper (provided as an option),
located at the process air outlet.
Reactivation airflow is set using an internal
slide-gate damper. Refer to section 3.6,
“Monitoring Unit Performance” for a detailed
description on monitoring and setting
airflows.
3. Verify that amp draws of each component
are within ±10% of the ratings shown on the
Unit Nameplate.
4. Verify the operation of all switches and
safeties.
5. The green Unit On and red fault indication
lights are equipped with “press-to-test”
capability. This feature can be used to test
operation of the lamp element when main
power is on. If a “press-to-test” light does not
illuminate when pressed, it may be burned
out or the electrical connections may be
faulty.
6. Depending on the control methodology, set
the humidity or dew-point to the desired
setting with the system controller.
7. Insert a temperature probe into the
reactivation discharge opening and note the
temperature. The temperature leaving the
rotor can be as high as 180 °F. The
reactivation discharge temperature is
typically 120–140 °F at full heater output.
However, the dehumidifier may operate
above or below this range based upon
process and reactivation inlet air conditions
and volumes.
NOTE: The reactivation air temperatures
mentioned above may vary between DEZ
systems. See the Technical Data Sheet for
your unit for target temperatures.
8. Verify the grain depression across the
system (in the process airstream) is correct
per the Unit Nameplate.
During basic unit operation, process air will enter
one side of the unit cool and humid and leave the
other side of the unit warm and dry. Reactivation

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
10
air will enter one side of the unit cool and will leave
the other side very warm and moist.
3.3 Reactivation Heater Controller
This unit may be equipped with a solid-state
temperature controller or with a microprocessor-
based temperature controller. Generally, these
control devices are used to modulate the on-board
reactivation heater to maintain the reactivation
discharge air temperature setpoint. The controller
is shipped from the factory pre-programmed. The
source manufacturer’s instructions for the
controller are provided under separate cover.
Refer to the source manufacturer’s manual for
detailed information on operating the controller
and adjusting control parameters.
3.4 Capacity Control
The DEZ Series 1000 can be configured with one
of two controllers: A Watlow controller, which
comes standard with the unit, or optionally, the
STULZ E2microprocessor controller. The control
methods (described in the following sections) that
are available to the unit depend on which
controller is used.
The Watlow controller provides two basic control
methods 1) D-Stat and 2) D-Stat II. The E2
controller supports both of these methods, plus
H-Trac, Dew-Trac, and C-Trol II methods.
Refer to your order sheet or DIN Sheet for the
control method used in your unit.
3.4.1 D-Stat
What it Does:
This control method cycles the dehumidifier
on and off to maintain the relative humidity
setting.
Requires:
A wall-mounted humidistat or dry contact to
enable remote start/stop.
How it Works:
The dehumidifier responds to a control signal
from a humidistat (provided as an option) or a
customer-supplied dry contact control signal
which cycles the unit on and off to maintain
the relative humidity setting. See section
3.5.1, Mode Selector Switch for the correct
mode setting to enable humidistat control.
3.4.1.1 D-Stat II
This control method function is similar to D-Stat,
except the process blower runs continually. The
reactivation heater and blower cycle on and off in
response to a humidistat (provided as an option)
or a customer-supplied dry contact control signal.
3.4.2 H-Trac
What it Does:
This control automatically regulates the
reactivation heater to provide constant
process discharge or space relative humidity.
Requires:
A factory or space-mounted RH
sensor/transmitter and adjustable setpoint
microprocessor controller.
How it Works:
The controller sends a signal to the on-board
reactivation heater modulation control system
to maintain the relative humidity setpoint. The
dehumidifier runs continuously and
continually adjusts capacity in response to
load changes. In the AUTO mode, the
dehumidifier responds to a customer-supplied
start/stop signal.
3.4.3 Dew-Trac
What it Does:
This control method regulates the reactivation
heater to provide constant process discharge
or space dewpoint temperature.
Requires:
A factory or space-mounted dewpoint
transmitter and adjustable setpoint
microprocessor controller.
How it Works:
The controller determines the amount of
reactivation energy required to maintain the
dewpoint setpoint and develops an
appropriate control output. The dehumidifier
runs continuously and the controller
continually adjusts reactivation heat in
response to load changes. In Remote mode
the dehumidifier responds to a customer-
supplied start/stop signal.
3.4.4 C-Trol II
What it Does:
This control method regulates reactivation
heat, to prevent condensation from forming on
cold surfaces, by maintaining the ambient
dewpoint temperature below the temperature
of the cold surface.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
11
Reactivation Air
Discharge Temperature
Process Control
Humidity Setpoint
Process Control
Humidity Actual
PI
Reactivation Heater
Temperature Actual
PI
Reactivation
Heater Setpoint
Reactivation
Heat Output
PI
Reactivation Air
Discharge Setpoint
Minimum
Requires:
A cold surface temperature sensor (or
temperature sensor at coldest point in room),
an ambient dewpoint temperature transmitter,
and an E² microprocessor controller.
How it Works:
The controller determines the amount of
reactivation energy required to maintain
dewpoint temperature. The controller
compares the cold surface temperature to the
ambient dewpoint temperature and develops a
control output. The dehumidifier runs
continuously and the controller continuously
adjusts reactivation heat in response to load
changes. The dehumidifier maintains the
space dewpoint at 5 °F (adjustable) less than
the cold surface temperature.
In Remote mode the process blower runs
continuously and the dehumidifier responds to
a customer-supplied start/stop signal.
3.4.5 Proportional Reactivation Controls
(H-Trac or Dew-Trac)
If the system is configured for H-Trac or Dew-Trac
reactivation control, the unit proportionally controls
humidity. When the Humidity PI loop output
exceeds 0%, the reactivation heater and
reactivation blower turn on. The controller
calculates PI loop outputs for humidity,
reactivation discharge air temperature and
reactivation heater temperature (see Figure 4).
As each of these PI loop outputs modulate, the
controller selects the lower PI loop output and
uses that output to control the reactivation heater.
Note: This methodology prevents overheating of
the desiccant, which would result in diminished
drying performance. Once the Humidity PI loop
output drops to 0% for the “Reactivation Idle” time,
the Energy Savings Feature shuts off reactivation
but the process blower continues to operate,
ensuring accurate humidity measurement and
control, even when dehumidification isn’t required.
Figure 4 - Proportional (Trac) Control Diagram
3.5 Control Panel
The control panel on the unit will vary depending on
whether the unit is equipped with a standard Watlow
controller or an optional E2microprocessor controller.
E2-equipped units typically have a single red Fault
Status light that notifies the operator that a fault has
occurred; the actual fault is indicated on a display
connected to the E2. Units without an E2controller can
have one or more indicators, each indicating a
different fault or status.
Units also have a three-way rotary switch labeled
ON/OFF/AUTO or LOCAL/OFF/REMOTE as
described in section 3.5.1. Two representative
control/Indicator layouts are illustrated in Figure 5 and
Figure 6.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
12
W
G
R
ON AUTOOFF
POWER ON UNIT ON HIGH
REACTIVATION
TEMPERATURE
Figure 5 - Sample Non-E2Control Panel Layout
Figure 6 - Sample E2Control Panel Layout
3.5.1 Mode Selector Switch
The DEZ Series 1000 unit has a three-position
selector switch located on the front side of the unit.
The table below describes the modes of operation set
by the switch:
Mode Description
OFF
Unit is off, power is still live if the main
disconnect is On; the white “Power On”
indicator light is illuminated.
ON/
LOCAL
Unit is on and runs continuously; green
“Unit On” indicator light is illuminated.
AUTO/
REMOTE
Unit cycles on and off in response to a
humidistat or Remote Start/Stop signal;
green “Unit On” indicator light is
illuminated when the unit is running.
NOTE: The unit will not operate in the AUTO mode
unless a humidistat is installed or the appropriate
connection is made on the unit terminal block to enable
remote start/stop control of the dehumidifier. Refer to the
electrical diagram for specific wiring connections.
NOTE: The reactivation blower and the rotor may
continue running for five minutes after the unit cycles off
to remove residual heat from the unit (dependent on
controller).
3.5.2 Hour Meter
An hour meter inside the electric box gives the
elapsed run time for scheduling maintenance.
3.5.3 Control Panel Lights
The unit is equipped with indicator lights to notify the
operator of the current status of the unit. The green
“Unit On” and red fault indicator lights are equipped
with “press-to-test” capability. This can be used to
verify lights are working. If a light does not illuminate
when pressed, it may be burned out or the electrical
connections may be faulty. For specific information
regarding troubleshooting indicator lights, refer to the
Refer to section 6.0, Troubleshooting and to the
electrical drawing provided with your unit.
The light icon next to the light name in the
following text contains the light’s color: Wfor white, G
for green and Rfor red.
POWER ON
This illuminates white when main power is supplied to
the unit.
UNIT ON
This illuminates green when main power is supplied to
the unit and the unit is running.
3.5.4 Optional Fault Indication Lights
This unit may be equipped with optional, fault
indication light(s). Refer to the DIN Sheet that is
provided with the unit for the characteristics of this unit
and the optional features that are included.
SUMMARY FAULT
If unit is equipped with an E2 controller, this indicator
will be provided to illuminate red when any of several
pre-programmed faults occur, such as a high
reactivation temperature fault, rotor rotation fault, a
fault with the unit motors or insufficient reactivation
airflow across the air proving switch. As an option, the
controller may be programmed to activate the
summary fault light upon detecting other pre-defined
fault conditions or to provide certain status
notifications such as dirty filters.
LOCAL REMOTEOFF
POWER ON UNIT ON SUMMARY
FAULT

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
13
R
R
HIGH REACTIVATION TEMPERATURE
FAULT
This illuminates red (and the reactivation heater shuts
down) when the reactivation air temperature entering
the rotor or the air temperature leaving the rotor is
above the high temperature limit. A manual reset of
the temperature limit switches is necessary. Refer to
section 6.0, Troubleshooting.
ROTOR ROTATION FAULT
This illuminates red if the rotor has not made a
complete revolution within a specified period of time.
3.6 Monitoring Unit Performance
There are two differential pressure gauges on this
system which indicate the pressure drops across the
rotor (see Figure 7). Rotor pressure drop (static
pressure) correlates directly to airflow. In order to
maintain optimum performance, process and
reactivation airflows are set using the rotor pressure
drops. Refer to the Unit Nameplate for the appropriate
settings for the Rotor Pressure Drops (inches w.c.).
The Unit Nameplate indicates the pressure drops
across the rotor as set by the factory. After all
ductwork is installed during initial installation, the
airflows may need to be adjusted to re-establish rotor
pressure drops to the values indicated on the unit test
performance report.
Figure 7 - Differential Pressure Gauges
Set the airflows by adjusting the dampers while the
unit is still cold. The process air damper is generally
located in the process air outlet. The reactivation air
damper is located internally at the reactivation air
outlet.
Afterward, if the gauges show readings that are
significantly lower than the initial factory settings, the
filters may need to be replaced.
!
CAUTION
Do not operate the unit without
filters. It is better to operate the unit with dirty filters
than no filters. Operating the unit without filters may
void the warranty.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
14
4.0 UNIT FEATURES
This unit may be equipped with one or more of the
following options. For a detailed list of the options
purchased with this unit, refer to the Dehumidifier
Identification Number (DIN) sheet provided with the
unit (see section 1.2.2). The DIN number for this unit
can be found on the DIN sheet.
4.1 Control Sensor Terminals
The unit is equipped with terminal positions for the
connection of a humidistat (S7) or relative humidity
transmitter (TN11) for utilizing the selected control
method (see section 3.4, Capacity Control). A
humidistat or relative humidity transmitter (optionally
provided) is required for the control scheme to
function. Refer to the electrical drawing for details on
interfacing the control sensor with the equipment.
4.2 Remote Start/Stop Contact
The unit may be equipped with optional terminal
positions to connect a remotely operated “Start/Stop”
control device. It may be used to start and stop the
unit when the mode selector switch is in the “Auto”
position. When the circuit is closed the unit will start
operating; when opened the unit will stop operating
(after the purge cycle). The contact must be correctly
sized to match the voltage and current requirements
of the circuit. Refer to the electrical drawing to
determine the correct rating for the contact and for
wiring details. NOTE: The unit will not start if the
space humidity is below setpoint.
4.3 Optional Customer Contacts
The unit may be equipped with optional customer
interface contact positions located on terminal blocks
in the electrical enclosure(s). The contacts are utilized
for remote monitoring and control purposes. Certain
status contacts may operate together with an
assigned status indicator light. Refer to the unit DIN
sheet to determine which status contacts and indicator
lights are provided with this unit.
NOTE: Refer to the electrical drawing for specific ratings
of the contacts and for wiring details.
ROTOR ROTATION FAULT CONTACT
This contact closes if the rotor has not made a
complete revolution within a specified period of time.
PROCESS BLOWER INTERLOCK DRY CONTACT
This contact closes when the process blower is
operating. It can be used to indicate unit operating
status or to start and stop auxiliary equipment such as
a circulating fan or condensing unit.
SUMMARY FAULT CONTACT
This contact notifies the operator of such problems as
a heater fault, rotor motor fault or a fault with the
process and/or reactivation blower motors.
REACTIVATION AIR PROVING CONTACT
This contact closes when the unit is turned on and the
reactivation air proving switch detects sufficient
airflow. When the unit is on, the contact opens upon
loss of reactivation airflow and the reactivation heater
will be de-energized. When the airflow problem is
corrected, the heater will automatically re-energize.
PROCESS AIR PROVING CONTACT
This contact closes when the unit is turned on and the
process air proving switch detects sufficient airflow.
When the unit is on, the contact will open upon loss of
process airflow.
DIRTY FILTER CONTACT
This contact closes when the differential pressure
across the process or reactivation air filter reaches a
predetermined value, indicating that the filter should
be cleaned and/or changed. The differential pressure
gauges may be used to determine which filters should
be serviced (see section 3.6, Monitoring Unit
Performance).
4.4 Sensor Retransmit Terminals
The unit may be equipped with optional terminal
positions for monitoring unit performance by means of
analog output signals that indicate operating
parameters of the system. The system controller
translates signal inputs for temperature as measured
by the sensors. The controller retransmits the values
as output signals to terminal block(s) located inside
the electric box. Refer to the electrical drawing for the
analog output signals provided, their applicable range
and for wiring details.
4.5 Electrical Disconnect
The unit may be equipped with an optional fused or
non-fused electrical disconnect switch. A switch is
recommended and may be required by local or
national electrical codes. Rotary disconnects are
located on the front of the electrical enclosure. Knife-
style disconnects have a separate box located
adjacent to the electrical enclosure. The disconnect
switch allows power to be removed during
maintenance or service functions. If a disconnect
switch is not provided, the unit will have power when

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
15
the electrical connections to the main power terminal
block (TB1) are made. Use caution when servicing the
unit. For wiring details, refer to the electrical drawing
for this unit.
Even with the optional Disconnect
switch in the Off position, incoming power may still
be live between the switch and the main power
source. Power must be disconnected from the main
source before servicing.
4.6 Emergency Stop
The unit may be equipped with an optional emergency
stop switch button mounted on the control panel.
Press the button to disconnect control power from the
unit to cease operation. To restore control power,
twist the switch button to release it and it will return to
the normal position.
NOTE: The emergency stop switch disconnects
control power from the unit contactors, causing them
to open. Main power remains present inside the unit
after the emergency stop switch is pressed.
4.7 Dampers
The unit may be equipped with an optional, manually
adjustable air damper for the process air outlet. The
damper is actuated by means of a slide/lock control
handle located on the side of the duct transition. An
internal slide gate damper is supplied as standard
equipment at the reactivation air outlet. The dampers
are used to adjust the process and reactivation
airflows for optimal unit performance after installation
of the ductwork is complete. Refer to section 3.6,
Monitoring Unit Performance.
4.8 Filter Status
The unit is equipped with 30% efficient pleated filters
on the process and reactivation air inlets. An optional
status contact may be assigned to these filters to
notify the user when they must be cleaned or
replaced.
!
CAUTION
Do not operate the unit without
filters. It is better to operate the unit with dirty filters
than no filters. Operating the unit without filters may
void the warranty.
4.9 Voltage Sensor/Phase Monitor
The unit may be equipped with either a voltage sensor
or a phase monitor device. A voltage sensor (used on
single phase units) causes the control power to be
interrupted in the event of low line voltage. A phase
monitor (used on 3 phase units) causes the control
power to be interrupted in the event of an incorrect
phase sequence, loss of a single phase, low voltage,
or voltage unbalance. This protects the unit’s motors.
An automatic reset occurs when the fault condition is
corrected. An LED on the device will illuminate to
indicate that operating conditions are normal.
4.10 Process Air Proving
The unit may be equipped with an optional process air
proving switch. Operation of the dehumidifier’s
reactivation circuit is enabled only when there is
process airflow. The process air proving switch closes
when the unit is turned on and the air proving switch
has detected sufficient airflow. The switch opens upon
loss of process airflow, disabling the reactivation
circuit. An alarm is signaled if process airflow is
inadequate. When the airflow problem is corrected
and the alarm is reset, the reactivation heater
automatically resumes normal operation.
4.11 E2Controller and Display
Figure 8 - E2Controller and Display
The unit may be equipped with an E2microprocessor-
based controller located in the main electric box. The
controller is furnished with factory configured software
designed to maintain space or process discharge air
conditions (temperature and/or humidity).
A display/keypad is provided for interaction with the
system controller. It may be located in the main
electric enclosure, in a separate “window” box
mounted on the unit or shipped loose for field
installation.
Press the alarm ( ) key on the keypad to call up
alarm screen messages. After the alarm condition is
corrected, press the alarm key again to reset the
controller and resume normal operation.

DEZ SERIES 1000 INSTALLATION,OPERATION AND MAINTENANCE MANUAL
16
5.0 PREVENTIVE MAINTENANCE
Minimal periodic Preventive Maintenance Checks and
Services (PMCS) are recommended to ensure optimal
performance of the unit. Routine maintenance can
correct deficiencies before they cause serious
damage to the equipment and helps ensure the unit is
ready for operation at all times.
A schedule for preventive maintenance inspection and
service should be established immediately after
installation of the unit. A system should be established
to record any problems, defects, and deficiencies
noted by operators and discovered during
maintenance inspections, together with the corrective
actions taken. Use copies of the Periodic General
Maintenance Checklist in Appendix A to record
maintenance inspections. For assistance, contact
STULZ Product Support.
The following sections list the preventive maintenance
checks and services that should be performed and
their recommended intervals. When operating under
extreme or unusual conditions, such as in a very dusty
or sandy environment, it may be necessary to reduce
the maintenance intervals indicated. The schedule
below assumes that your system operates
continuously.
Disconnect all power before
performing any service or maintenance function.
Turning the unit mode selector switch to the “Off”
position does not disconnect the power.
5.1 Monthly
Check all electrical connections to ensure they are
tight and not shorted to ground.
Ensure that the control panel lights are functional
and not burned out. (Use the “press-to-test”
feature.)
Remove, clean, and/or replace filters to ensure
proper airflow through the unit. If your
environment is exceptionally dusty or sandy, this
may be required on a more frequent basis.
Check that the rotor seals for wear and ensure the
seals are touching the rotor face and rotor flange.
Check the rotor drive belt for signs of abnormal
wear.
Check each blower mounting and inspect the
blower wheel for loose fasteners. Tighten if
necessary. Ensure that the wheel is free of debris.
Lubricate motor bearings if necessary.
Check that shaft key, pulley, and bearing
lockdowns are tight.
5.2 Yearly
Thoroughly clean the unit inside and out, making sure
to remove any dust from fan blades.
5.3 Desiccant Rotor Drive Motor
Maintenance
A speed-reducing gear motor rotates the desiccant
rotor. The gear motor bearings are pre-lubricated and
do not require re-lubrication. Periodically inspect
around the gear motor for accumulated dirt and
remove it by vacuuming. Also observe the motor while
operating for high motor current, unusual noises or
vibration, overheating, worn or loose couplings and
belts or loose mounting bolts.
!
CAUTION
Dirt accumulation can cause motor
heating and a fire hazard.
5.4 Blower Motor Maintenance
5.4.1 General Inspection
Inspect the blower motors at regular intervals
(approximately every 550 hours of operation or every
3 months). Keep the motors clean and make sure all
ventilation openings are clear. The steps listed below
should be performed at each inspection.
Voltages used with this unit can
be deadly. Use the services of a qualified
electrician and/or technician to make the electrical
power connections and perform maintenance.
1. Ensure the motor is clean. Check to make sure
the interior and exterior of the motor are free of
dirt, oil, grease, water, etc., which may
accumulate and block motor ventilation. If the
motor is not properly ventilated, overheating can
occur and cause premature motor failure.
2. Use a “Megger” periodically to verify the
integrity of the winding insulation and record the
readings. If there is a significant drop in
insulation resistance, immediately investigate.
3. Ensure all electrical connections are tight.