Stulz DAH User manual

DAH
Ducted Air Humidier
Installation, Operation and Maintenance Manual
Ultrasonic Humidication
DAH Series
GEN2
Installation, Operation and Maintenance Manual
Energy Efficient Ultrasonic Humidifier

DAH Series GEN 2 Ultrasonic Humidifier IOM Manual
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 confidential and proprietary information of STULZ Air Technology Systems, Inc.
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Unpublished — rights reserved under the copyright laws of the United States and of other countries.
Other brands and tradenames are trademarks of their respective owners.
Copyright 2019 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
https://www.stulz-usa.com/en/

Series GEN 2 Ultrasonic Humidifier IOM Manual
Table of Contents
Energy Efficient Ultrasonic Humidifier ..................................................................................................... 1
Introduction.............................................................................................................................................. 1
Safety ................................................................................................................................................ 1
Safety Summary............................................................................................................................. 1
Specifications................................................................................................................................. 3
General Design..................................................................................................................................... 4
Main Parts ............................................................................................................................................ 4
Ultrasonic Nebulizer Unit ............................................................................................................... 4
Mist Outlet ...................................................................................................................................... 4
High Water Float Switch................................................................................................................. 4
Low Water Float Switch.................................................................................................................. 4
Water Fill Valve Solenoid ............................................................................................................... 4
Water Supply Valve ........................................................................................................................ 4
Water Supply Tubing ...................................................................................................................... 4
Drain and Overflow Assembly........................................................................................................ 4
Temperature Sensor ...................................................................................................................... 5
Solid State Relay ........................................................................................................................... 5
Level Controller.............................................................................................................................. 5
BoosterFan (Optional DAH-24/30 Only) ........................................................................................ 6
Mounting Rack (Optional) .............................................................................................................. 7
Installation ............................................................................................................................................... 8
Receiving the Equipment...................................................................................................................... 8
Site Preparation.................................................................................................................................... 8
Mounting and Placement....................................................................................................................... 10
Supply and Drain Piping ..................................................................................................................... 12
Main Power and Control Wiring ......................................................................................................... 13
Wire Sizing — Control Box to Humidifiers ................................................................................... 13
Connecting Humidifier(s) to Control Box...................................................................................... 14
Single Humidifier.......................................................................................................................... 15
Multiple Humidifiers (Grouped) .................................................................................................... 15
Multiple Humidifiers/Optional Multi-Tier Mounting Rack (Grouped)............................................. 15
Operation............................................................................................................................................... 16
Purge the Water Line .......................................................................................................................... 16
Initial Operation Checklist................................................................................................................... 16
Operation Procedure .......................................................................................................................... 16
Precautions......................................................................................................................................... 17
Steps for Long Term Shutdown .......................................................................................................... 17
Maintenance .......................................................................................................................................... 18
Periodic General Maintenance ........................................................................................................... 18
General Maintenance................................................................................................................... 18
Maintenance Items and Tools ............................................................................................................. 19
Electrical Parts ............................................................................................................................. 20
Float Switches.............................................................................................................................. 21
Water Tank................................................................................................................................... 21
Water Supply Strainer/Flow Regulator......................................................................................... 21
Troubleshooting and Repair ............................................................................................................... 22
Common Repairs and Parts Replacement .................................................................................. 24
Temperature Sensor on Water Tank............................................................................................. 25
Replacing a Transducer ............................................................................................................... 25
Replacing a Nebulizer Print Plate ................................................................................................ 22
Water Solenoid Valves, Float Switches and Level Control Board................................................ 22
Fill Solenoid Valve........................................................................................................................ 22
Drain Solenoid Valve ................................................................................................................... 23

Series GEN 2 Ultrasonic Humidifier IOM Manual
Float Switches.............................................................................................................................. 23
Level Control Board ..................................................................................................................... 23
Product Support .................................................................................................................................... 24
Technical Support............................................................................................................................... 24
Obtaining Warranty Parts ................................................................................................................... 24
Obtaining Spare and Replacement Parts.............................................................................................. 26
Drawings................................................................................................................................................ 27
Unit Component Layout Drawing of Humidifier (Exploded View)....................................................... 27
DAH-04/16 - Typical Wiring Diagram for Modbus Version .......................................................... 28
DAH-04/16 - Typical Wiring Diagram for Stand-Alone Version ................................................... 29
DAH-24/30 - Typical Wiring Diagram for Stand-Alone Version ................................................... 30
DAH-24/30 - Typical Wiring Diagram for Stand-Alone Version ................................................... 31
Figures
Figure 1. Ultrasonic Humidifier- Model DAH-16 ........................................................................................ 2
Figure 2. Booster Fan Assembly ............................................................................................................... 6
Figure 3. Humidifier Mounting Rack (Front View, Shown with Five Humidifiers) ...................................... 7
Figure 4. Ultrasonic Humidifier Mounting................................................................................................. 10
Figure 5. Duct Mounting — Vertical Arrangement ................................................................................... 11
Figure 6. Duct Mounting — Cascade Arrangement................................................................................. 11
Figure 7. Water Supply and Drain ........................................................................................................... 12
Figure 8. Power and Control Wiring......................................................................................................... 13

Series GEN 2 Ultrasonic Humidifier IOM Manual
Nomenclature
DRH-04-S
DRH DAH S Number of
Transducers
Ducted Air
Humidifier
Ducted Air
Humidifier
(Blank) =
Ultra Series
Control
S = Stand
Alone
04, 08, 12, 16,
24, 30

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Introduction
Recognized as a world leader, STULZ Air Technology Systems, Inc. (STULZ) Ultrasonic humidifiers are
designed and manufactured with the highest quality craftsmanship using the finest materials available.
Your ultrasonic humidification system will provide years of trouble free service if installed and maintained
in accordance with this manual.
Damage to the unit from improper installation, operation or maintenance is not covered by the warranty.
This manual contains information for installation, operation, maintenance, troubleshooting and repair.
Study the instructions contained 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 components in order to continue operation is not
recommended and will void the warranty. Due to technological advancements, components are subject to
change without notice.
DAH Series Ultrasonic Humidifiers are designed for use with a central air handler unit (AHU). They may
be rack mounted in an AHU or mounted in the air distribution ductwork.
Any use beyond this is deemed to be not intended. STULZ is not liable for any damage resulting from
improper use. The system is designed to be installed indoors unless otherwise noted on the equipment
nameplate.
Safety
STULZ uses NOTES along with CAUTION and WARNING symbols throughout this manual to draw your
attention to important operational and safety information.
A bold text Note marks a short message in the information to alert you to an important detail.
A bold text CAUTION safety alert appears with information that is important for protecting your
equipment and performance. Be especially careful to read and follow all cautions.
A bold text WARNING safety alert appears with information that is important for protecting you from harm
and the equipment from damage. Pay very close attention to all warnings that apply to your application.
A safety alert symbol accompanies a general WARNING or CAUTION safety statement.
A safety alert symbol accompanies an electrical shock hazard WARNING or CAUTION safety
statement.
Safety Summary
The following statements are general guidelines followed by warnings and cautions applicable throughout
the manual.
Prior to performing any installation, operation, maintenance or troubleshooting procedure read and
understand all instructions, recommendations and guidelines contained within this manual.
WARNING
High voltage is used in the operation of this equipment. Death on contact may result if personnel fail to
observe safety precautions.
CAUTIONS
This unit must be installed according to local and national electric codes.
All maintenance and/or repairs must be performed by a qualified technician. All personnel working on or
near equipment should be familiar with hazards associated with electrical maintenance.
Always turn off the main power and unplug the unit before beginning work on the equipment.

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Series GEN 2 Ultrasonic Humidifier IOM Manual
NOTES
Wiring terminations may become loose during transit of the equipment therefore; verify all wiring
terminations are secure prior to operation.
Do not attempt to make repairs without the proper tools.
NOTE: STULZ offers no warranty protection on humidification systems using controls not provided by STULZ.
CAUTIONS
It is essential that De-ionized (DI) or Reverse Osmosis (RO) water be used as the supply water source to
maintain full warranty coverage. The use of untreated water will VOID THE WARRANTY.
Use only non-corrosive stainless steel or poly tubing rated for use with DI water to supply the humidifier.
Provide a drain with an air gap per local and national plumbing codes.
Never block the mist outlet or the opening of the air inlet. The humidifier may be filled with the condensed
mist and electrical shorts may result.
Observe the unit for water leakage. A short circuit could occur if the humidifier is splashed with water
while operating.
Never attempt to remove the mist guide cover and/or the mist blow tubes while the humidifier is operating,
or electrical shorts may result.
If there is a risk of supply water freezing, pipe insulation should be provided.
Never apply power when the humidifier is overturned or upside down. Damage to the ultrasonic nebulizer
unit or transducer may result.
Never drop the humidifier or apply hard shock to it as this may damage internal parts.
Drain the water in the tank for sanitary reasons when humidifier is turned is off for more than 3 days.
Figure 1. Ultrasonic Humidifier Model DAH-16

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Specifications
Type DAH Series Ultrasonic Humidifier Model
Model DAH-04 DAH-08 DAH-012 DAH-16 DAH-24 DAH-30
Nebulizing capacity, lb/h 5.3 10.6 15.8 21.1 30.8 39.6
Qty. of ultrasonic nebulizers/unit 4812 16 24 30
Power source, VDC 48
Rated power consumption, W 125 246 366 486 726 906
Weight, lb 15.4 21.7 28.0 34.3 37.5 44.1
Electrical Characteristics
Allowable voltage range, VDC 47-51
Insulation resistance, MOhms 100 or more (excluding solid-state components).
Dielectric voltage withstand Operational when 1500 VAC is applied for 1 minute (excluding solid-state
components).
Operating conditions
Ambient working conditions 34 °F to 122 °F; 90%RH or less.
Water supply quality DI or RO water. Water conductance <5 microsiemens purity.
Water supply pressure, psi 30 to 75
Water supply temperature, °F 40 to 104
These parts must be provided by the user:
DI or RO supply water, Water supply valve, Water supply tubing (1/4” stainless steel or poly tubing rated for DI
water), power supply wiring and control wiring to the control box.
1. Calcium, magnesium or other agents that may be contained in the supply water are
atomized into the air together with the mist and may form white powders after the water
has evaporated. To avoid this, always use DI or RO supply water.
2. The nebulizing capacity of the transducer in the ultrasonic nebulizer unit decreases
gradually with use. It should usually be exchanged after about 10,000 to 15,000 hours of
operation, (depending on water quality and suitable voltage), although the unit may
continue to run as long as its effective capacity meets the particular requirements.
3. To ensure full warranty coverage, the input voltage to the humidifier must not exceed
51VDC. If the input voltage exceeds 51VDC, damage to the transducers and print plates
will result.

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Series GEN 2 Ultrasonic Humidifier IOM Manual
General Design
The DAH Series Ultrasonic humidifier directly atomizes water with high frequency mechanical oscillation,
producing a fine mist to be delivered into the room by the laminar airflow of an AHU fan.
DAH humidifiers may be mounted in the air distribution ductwork or rack mounted in the AHU. For large
AHU applications with low AHU air velocity, ultrasonic humidifier models DAH-24 and DAH-30 may be
equipped with an optional booster fan to propel the mist out.
The humidifier uses high frequency nebulizers to produce ultrasonic waves and an automatic water supply
mechanism to maintain the supply water at a constant level. When conducting routine maintenance, it is
important to clean the water tank because it significantly affects the humidifying capacity and life of the
ultrasonic nebulizers.
Main Parts
Ultrasonic Nebulizer Unit
This consists of a modular assembly located in the bottom of the water tank incorporating a 1.6 MHz power
oscillator on and a piezoelectric transducer. The transducer vibrates at that frequency, developing ultrasonic
columnar waves in the water and producing a fine mist above that column.
Mist Outlet
Directs mist out of the humidifier and eliminates larger mist particles so the humidifier only introduces fine
mist into the air stream.
High Water Float Switch
For maximum atomization, it is essential the water level in the tank be constantly maintained. The High
Water Float Switch is an input to the Level Controller. It is open when the water level is below the optimal
level and is closed when the water level reaches the maximum level.
Low Water Float Switch
Operating the humidifier when the water level is below the top of the transducers will damage the Ultrasonic
Nebulizer unit. The Low Water Float Switch is an input to the Level Controller. It is open when the water level
is near an unsafe level and is closed when the water level is at a minimal level.
Water Fill Valve Solenoid
The Water Fill Valve Solenoid is a 24VDC solenoid that allows water from the water supply to enter into the
tank when energized by the Level Controller. There is an orifice to restrict the flow of water.
Water SupplyValve
NOTE: This is to be provided by the user.
A valve must be installed upstream from the humidifier for service and maintenance. The valve must be
rated for use with DI water.
Water SupplyTubing
NOTE:Thus user must provide the water supply tubing.
Water supply tubing must be provided to connect the water supply to the water strainer/flow regulator in
the back of the unit. The strainer/flow regulator is equipped with a 90° swiveling, ¼” push-to-connect fitting.
Use ¼” stainless steel or poly tubing rated for use with DI water.
Drain and Overflow Assembly
The Drain and Overflow Assembly contains a 24VDC drain solenoid valve, an overflow pipe and a drain

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Series GEN 2 Ultrasonic Humidifier IOM Manual
outlet. The drain valve solenoid is controlled by the Level Controller to drain water from the tank via the
drain outlet. If the water level in the tank exceeds the height of the overflow pipe, the excess water is
diverted to the drain outlet. The drain outlet pipe is 1/8” MPT and ships with a stainless steel cap.
Temperature Sensor
The temperature sensor monitors the temperature of the tank and is read by the Level Controller which
prevents overheating and freeze protection
Solid State Relay
The 48VDC operating voltage for the Ultrasonic Nebulizer Units is switched on and off by a solid state DC
relay controlled by the Level Controller.
Level Controller
The Level Controller is a microprocessor based device located in the electric box that receives inputs
from sensors and other inputs and in turn controls the valves, fan and Ultrasonic Nebulizer units. It
consists of a DC-DC power supply to convert the 48VDC to 24VDC for the fans and solenoids and a
further reduction to 5VDC for the microprocessor, sensors, power switches and either a Modbus interface
to communicate with the Ultra-Series Control box or a simple standalone input interface depending on
which model humidifier was purchased.
The 48VDC must be present at all times to allow the Level Controller microprocessor to monitor the inputs
and control the outputs.
The microprocessor monitors the On and Off command from either the Modbus or the input dry contact
(depending on which model was purchased). If commanded on, the microprocessor checks the Low
Water Float Switch and the High Water Float Switch. If the water is too low, the microprocessor turns on
the Water Fill Valve Solenoid and monitors the Float Switches.
When the water level is above the low water level, the fan is turned on. When the water level is above the
high water level, the Water Fill Valve Solenoid is turned off and the Solid State Relay is turned on. When
the water level falls below the high water level, the microprocessor turns the Water Fill Valve Solenoid on
again to maintain optimal water level. When the on/off command is removed, the Solid State Relay is
turned off and, after a few seconds time delay to eliminate the remaining mist out of the humidifier, the
Fan is turned off.
Proportional control is accomplished by the microprocessor monitoring the proportional signal from the
Modbus or proportional input (depending on which model was purchased). When the proportional signal
is greater than 10% of the maximum input, the microprocessor will turn the Solid State Relay on and off in
a pulse-width modulation control. The period of the pulse width is 1 seconds.
For 10% control, the Solid State Relay is turned on for 0.1 seconds and off for 0.9 seconds. The on time
increases as the input approaches 100%. At 100%, the Solid State Relay is on continuously.
Safety control is built into the microprocessor. The voltage applied to the transducer controls the amount
of mist produced. Too high a voltage can cause damage to the transducer and too low a voltage prevents
mist from being formed. The microprocessor monitors the 48VDC to be with a range of voltages. If the
voltage is out of range, the microprocessor will not energize the Solid State Relay.
If the temperature of the tank rises too high, the microprocessor will turn off the Solid State Relay. If the
temperature approaches freezing, the microprocessor will turn off the Solid State Relay and the fan, and
then drain the tank to prevent damage from freezing water. When the temperature returns to a safe level,
normal operation is resumed.
A low level alarm is annunciated when the microprocessor sees the Low Level Float Switch indicate low
water after the tank has been filled. A fill alarm is annunciated when the High Water Float Switch does
not indicate the water level has been achieved after a predetermined amount of time.
A transducer alarm is annunciated if the transducers have been energized and no water is used in a
predetermined time (indicating no transducer is functioning). For the Modbus version of the Level

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Controller, failure to receive commands on the Modbus within a predetermined amount of time will
annunciate a communications alarm.
The Level Controller has an LED that displays, by blinking, any alarm condition that occurred after power
up. Each alarm is associated with a number of blinks, followed by a pause, and then the next alarm is
displayed. To view the LED, the Mist Guide Cover must be removed and the electrical access cover
removed. The LED blink pattern for each alarm is provided below:
Number of
Blinks Alarm Condition
1
Low Voltage
2
High Voltage
3
Freeze
4
High Temperature
5
Low Water
6
Fill Alarm
7
Communications
8
Transducer
BoosterFan (Optional DAH-24/30 Only)
DAH Series Ultrasonic Humidifiers are to be installed in air handlers or air ducts designed with a terminal
velocity of 450 to 750 FPM across the humidifier so the mist is readily eliminated by the pressure drop
caused by the air passing over the mist guide. When using continuously adjusting fan speeds in air handlers,
it is possible for the air velocity to drop below the minimum velocity (300 FPM) required to direct the mist
out of the humidifier.
An optional booster fan assembly may be attached to the back of the humidifier for such applications
(available for DAH-24 and 30 units only). The booster fan provides the minimum air flow needed to direct
the mist from the humidifier even when it is operating in an air stream with less than the minimum required
velocity.
Figure 2. Booster Fan Assembly
AIR IN
AIR OUT

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Mounting Rack (Optional)
A multi-tier mounting rack can be provided. This enables the assembly of 1 to 5 ultrasonic units together for
installation in an AHU or in an air duct.
The mounting rack (Figure 2) is designed to support the total weight of the humidifiers mounted to it. It
establishes the optimal spacing between units to ensure efficient operation. The humidifiers are shipped
preassembled to the mounting rack. This conveniently combines all the humidifier(s) water connections.
For point to point wiring terminations, follow the electrical drawing supplied with your system.
A manual shut- off valve is installed for all the humidifiers on the rack. A water conductivity probe is shipped
loose for field installation in the customer provided supply piping.
Figure 3. Humidifier Mounting Rack
Front View with five Humidifiers

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Installation
Receiving the Equipment
Your Ultrasonic Humidifier has been tested and inspected prior to shipment. To ensure that your
equipment has been received in excellent condition, make a visual inspection of the equipment
immediately upon delivery. Carefully remove the shipping container and all protective packaging. Open the
box and thoroughly inspect the unit for any signs of transit-incurred damage.
If there is shipping damage, it must be noted on the freight carrier’s delivery forms before signing for the
equipment. Any freight claims must be done through the freight carrier. We ship all equipment FOB
factory. We are not liable for any equipment damage while in transit.
We can assist in the claim filing process with the freight carrier. Should any such damage be present,
notify Product Support by fax [phone], telephone [phone] or E-mail (parts@stulz-
ats.com).prior to attempting any repairs.
Check the equipment against the packing slip to see if the shipment is complete. Report all discrepancies
to the appropriate authority.
Contents of the package include:
Humidifier
Six foot long power cable with moisture-proof, twist-lock connector on one end
Installation, Operation and Maintenance manual
Avoid dropping or jarring the unit to prevent damage to the internal parts. The unit should always be
stored in a dry location prior to installation.
A Data Package has been sent with your unit. It contains this manual, system drawings, applicable SDS’s
and other applicable instructions based on the configuration and options selected for your unit. The data
package is provided for your unit in a clear plastic bag. These documents need to be kept with the unit for
future reference.
Site Preparation
Install the unit in a secure location in an AHU or in the discharge ductwork where it cannot be tampered
with and power cannot be inadvertently turned off. Allow access to the unit for routine operation, servicing
and maintenance.
A sight window may be installed on the side of the duct section for easy visual inspection. Position the
humidifier in such a way that it can be easily removed for future maintenance and inspection. A corrosion
resistant drain pan must be provided underneath the humidifier for collecting incidental mist output.
Ensure the drain pan is long enough to extend 20-inches beyond the discharge side of the humidifier
(Figure 4 and Figure 5). A stainless steel duct section with a panned section for drainage may also be used
(Figure 6). A drain line must be provided and a condensate P-trap is required.
The height of the trap must exceed the static pressure of the system to ensure proper drainage from the
pan. See Layout Drawing of Humidifier (Exploded View) and refer to the installation drawing provided
with your unit for the dimensions of the humidifier and the mounting holes.
NOTE: Working clearance requirements need to be established prior to mounting the unit. Refer to local
and national electrical codes.
The humidifier must be installed horizontally and level to ensure the float switches do not give a false
reading. When selecting the installation location, attention should be paid to the air flow so that the
atomized mist can be uniformly diffused. The humidifiers must have a face velocity of 450- 750 FPM
across the mist guide cover to carry the mist particles out.
When calculating the air velocity in the duct, remember to subtract the area taken by the humidifiers from

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Series GEN 2 Ultrasonic Humidifier IOM Manual
the overall area of the duct because they lower the available area and raise the air velocity. If air velocity
exceeds 750 FPM. The duct cross sectional area must be increased so the face velocity falls within the
recommended range (Figure 4 and Figure 5).
The enlarged duct section must extend at least 24 inches beyond the humidifiers in the direction of the air
flow to minimize condensation on the walls of the duct or air handler. Other variables that can affect
condensation are air temperature and turbulence. Avoid installing humidifiers in high turbulence areas or
immediately before or after an elbow.
If any obstacle exists in front of the atomized mist outlet, the mist will be condensed on the obstacle to form
water droplets. Humidifiers should never be placed one behind the other on the same level.
They must be placed either one directly above the other in the same vertical plane (Figure 4) or in a cascade
arrangement with the highest humidifier being the first one in the direction of the air flow (Figure 5). In either
case, minimum clearances between humidifiers must be maintained. The top and bottom humidifiers must
also have a minimum amount of space between them and between the top and bottom of the duct.
NOTE: Humidity control can only be achieved in a sealed room or if the room has vapor barriers
installed. It is recommended that walls, ceilings and floors be sealed to prevent migration of humidity.

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Mounting and Placement
Ultrasonic humidifiers are designed for mounting to a flat surface. Ensure the mounting surface is capable
of supporting the weight of the unit. Weight estimates can be found on the installation drawing provided
with your unit. Secure the unit with fasteners (field supplied by others) so that it will not move during
operation.
Figure 4. Ultrasonic Humidifier Mounting
SIDE VIEW

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Figure 5. Duct Mounting — Vertical Arrangement
Figure 6. Duct Mounting — Cascade Arrangement
NOTE: Provide access panel
sufficient for units to be removed.
ISOMETRIC VIEW
See Note
SIDE VIEW
VERTICAL ARRANGEMENT
NOTE: Provide access panel
sufficient for units to be
removed.
ISOMETRIC VIEW
See Note
SIDE VIEW
CASCADE ARRANGEMENT

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Supply and Drain Piping
The Ultrasonic Humidifier will require a field-installed water supply line and overflow drain line. Refer to the
piping diagram provided with your unit for details. For the water supply, use DI or RO water.
The water supply to the humidifier cannot be taken directly from the public water service. Untreated supply
water will leave a residue in the conditioned space where white powder that is dissolved in the water is
produced after evaporation from the calcium or magnesium.
In cases where water quality, especially residue from evaporation, pH, total hardness and water
conductivity exceeds or is outside the range of standard, routine maintenance intervals to ensure
continuous operation will be more frequent than usual. Also, the operating life of the transducers and print
plates will be significantly reduced.
Figure 7. Water Supply and Drain
CAUTION
It is essential that DI or RO water be used as the supply water source to maintain warranty coverage. The
use of untreated water will void the warranty.
NOTE: The water supply piping must be noncorrosive stainless steel or poly tubing rated for use with
deionized water.
Prepare the water supply piping. The water supply piping should be equipped with a water supply valve for
maintenance purposes (user provided) at a place as close as possible to the humidifier. The valve must
be rated for use with DI water.
After the water supply valve is installed, flushing should be done by supplying water (see Purge the Water
Line). This is a necessary step to prevent chips and oil in the piping from entering the humidifier.
Connect the water supply piping to the humidifier by means of a ¼” stainless steel or poly tubing (user
provided). A strainer or flow regulator is preassembled to the water inlet in the back of the humidifier.
The strainer or flow regulator is equipped with a ¼” push-to-connect, swivel 90° fitting (see Figure 6). If there
is a risk that the water supply piping could freeze, wrap the piping with insulating material.
A drain line rated for use with DI water must be provided from the I/8” MPT water tank drain stub in the rear
of the unit. Connect the drain line to the stub so that overflowing water can be directed into a drain pan or
an appropriate place (such as an open building drain).
The drain line must meet local and national plumbing codes, be sloped downward and away from the
Water Supply Tubing –
Push into Swivel Connector
Remove Cap from Drain Stub –
Connect Drain Line

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Series GEN 2 Ultrasonic Humidifier IOM Manual
humidifier, include and air gap, and the end must not be obstructed.
Main Power and Control Wiring
For wiring, refer to the electrical drawing supplied with your unit to determine the total number of
interconnecting conductors required for your system and for the proper wire terminations.
For internal wiring of the humidifier, see the Electrical Diagrams.
NOTES
Wiring terminations may become loose during transit of the equipment, therefore, verify all wiring
terminations are secure prior to operation. Provisions must be made to ensure the humidifier only
operates when there is air flow.
Verify that the main power supply to the control box coincides with the voltage, phase and frequency
information specified on the nameplate. The nameplate also provides the full load amps (FLA), the
current that the unit will draw under full design load, the minimum circuit ampacity (MCA) for wire sizing,
and the maximum fuse size (MFS) for circuit protection. For safety, the power source must be provided
with a circuit breaker.
Ensure a ground is connected to the unit. The humidifier is rated to operate with a nominal input of
48VDC. To maintain warranty coverage, never allow the humidifier input voltage to exceed 51 volts as
damage will occur to the transducers and print plates.
Wire Sizing — Control Box to Humidifiers
The table below indicates the correct electrical wire sizing from the control box to the humidifier power
cable for three different distances. All wire sizes listed are for stranded, THHN or NTW wire only. (Do not
use solid conductor wire.)For distances over 75 feet, contact Product Support for assistance by fax
[phone], telephone [phone] or E-mail ([e-mail]).
In addition to the above power wires, humidifiers controlled by the Ultra-Series control box use
RJ45/CAT5 data communication cables, daisy chained from the humidifier(s) to the control box.
The data communication cable is not to exceed 1000 feet total length from the control box to the last
humidifier. A termination resistor must be installed on the last humidifier as shown in the electrical
drawing provided with your unit.
CAUTIONS
The termination resistor is only to be placed on the last unit in the data communication string.
The power supply provided with the equipment is sized and selected based on the expected load. Do not
connect any additional loads to the control power supply.

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Series GEN 2 Ultrasonic Humidifier IOM Manual
Figure 8. Power and Control Wiring
Connecting Humidifier(s) to Control Box
As a standard, GEN2 Ultrasonic humidifiers are equipped with a twist lock power connector and two
RJ45 ports for data communication. The Ultrasonic Humidifier control box will also be equipped with an
RJ45 port for data communication. DAH Series Ultrasonic Humidifiers are designed to be installed in an
AHU or in discharge ductwork.
For this reason, a 6-foot power cable with a moisture-proof, twist-lock connector on one end is provided
with each humidifier. A 25-foot data communication cable is also provided with a moisture proof
connector at one end (humidifier connection). Consult Product Support for assistance by fax (301) 620-
1396, telephone [phone] or E-mail ([e-mail]).for optional cable lengths. The table
below lists the correct wire sizing from the Control Box to the Ultrasonic humidifiers for various models.
48 VDC Wire Sizing Room Control Box To Ultrasonic Humidifiers
Model Current
(Amps)
Wire Size (AWG)
# Of Wires
(Includes 1
Ground)
25 Ft 50 Ft 75 Ft
DAH-04
2.6
16
16
14
3
DAH-08
5.0
16
16
14
3
DAH-12
7.6
16
14
12
3
DAH-16
10.1
16
14
12
3
DAH-24
14.6
16
14
12
5
DAH-24 w/ BF-24
15.4
16
14
12
5
DAH-30
20.0
16
14
12
5
DAH-30 w/ BF-30
20.8
16
14
12
5
NOTE: Table reflects correct electrical wire sizing from the control box to
the humidifiers. Do not exceed 75 foot maximum distance.

15
Series GEN 2 Ultrasonic Humidifier IOM Manual
Single Humidifier
Once the Ultrasonic Humidifier and control box are installed, the total 48VDC wire length and wire size
(AWG) should be determined using the table below. A junction box (not provided) is necessary in the
AHU or ductwork to make the connection between the field-installed 48VDC power wiring and the factory
provided humidifier power cable.
The factory-provided 25 foot data communication cable must be installed with the moisture-proof RJ45
connector at the humidifier and the standard RJ45 connector at the control box.
The factory provided end-of-line termination resistor must be installed in the second RJ45 port of the
humidifier.
Multiple Humidifiers (Grouped)
Once the humidifiers and control box are installed, the total 48VDC wire length and wire size (AWG)
should be determined for each humidifier using the table on the preceding page.
A junction box (not provided) is necessary in the AHU or ductwork to make the connection between the
field-installed 48VDC power wiring and the factory provided humidifier power cable.
The factory provided 25 foot data communication cable must be installed with the moisture-proof RJ45
connector at the humidifier and the standard RJ45 connector at the control box.
Additional factory provided 20-foot RJ45 cable(s) with moisture-proof connectors at both ends must be
used to make the data communications connections between humidifiers within the humidifier or
ductwork.
The factory provided end-of-line termination resistor must be installed in the second RJ45 port of the last
Ultrasonic Humidifier.
Multiple Humidifiers/Optional Multi-Tier Mounting Rack (Grouped)
Once the humidifiers and control box are installed, the total 48VDC wire length and wire size (AWG)
should be determined for each humidifier using the table on the preceding page.
A junction box (not provided) is necessary in the AHU or ductwork to make the connection between the
field-installed 48VDC power wiring and the factory provided humidifier power cable. One junction box per
rack is typical.
The factory-provided 25-foot data communication cable must be installed with the moisture-proof RJ45
connector at the humidifier and the standard RJ45 connector at the control box.
Additional RJ45 cables with moisture-proof connectors at both ends will be factory installed to complete
the data communications connections between all humidifiers on a single rack. Factory provided 20-foot
RJ45 cables with moisture-proof connectors at both ends must be used to make the data
communications connections between multiple racks within the AHU or ductwork.
The factory-provided end-of-line termination resistor must be installed in the second RJ45 port of the last
humidifier.