Neptronic SKR3E Manual

SDU-SKR-CE-ENG-170428
SKR series Steam Humidifier
with SDU module
(Patent Pending)
Installation instructions
& user manual
READ AND SAVE THESE INSTRUCTIONS

SKR Humidifier with SDU
Foreword
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Foreword
Neptronic Company Overview
Founded in 1976, we’re a private corporation that designs, manufactures and distributes products for the HVAC industry.
Our product line includes intelligent controllers, electronic actuators, actuated valves, humidifiers and electric heaters.
Our products are designed and manufactured by over 250 dedicated employees in our 7,500 m2(80,000 ft2) state-of-the-
art facility located in Montreal, Canada. Using a vertical integration model, our entire manufacturing chain is under one
roof from software and hardware development, to SMT circuit board assembly, to sheet metal fabrication, to product
testing ensuring that our products are engineered to last.
We currently hold several national and international patents and with our continued commitment to research and
development, we provide innovative products and technologies for the ever-evolving challenges of the HVAC industry.
Exporting over 70% of our sales, we have an exclusive distribution network around the globe that provides
comprehensive solutions to our worldwide customers.
About the Manual
These installation and operation instructions have been developed to facilitate the installation of the Steam Humidifier.
The strict application of these instructions will ensure the conformity of your installation and operation as per
the manufacturer's recommendations.
The application of these instructions is one of the conditions for the application of the warranty.
The application of these instructions does not ensure, at any time conformity to procedures, regulation or
local codes, regarding electric installation and connection to local water supply.
This product has been declared to conform to the applicable Canadian and American safety standards and directives
and bear the CSA (c) & (us) mark. The Certificate of Conformity, CSA is available, upon request with the manufacturer.
This product has been declared to conform to applicable European safety and electromagnetic compatibility standards
and directives and bear the CE mark. The certificate of conformity CE is available upon request to the manufacturer.
2017©: All rights reserved. This document cannot be reproduced totally or partially by any means whether, electronic,
mechanical, photocopy, recording or other, without prior written authorization of Neptronic.
Electricity
All work concerned with electrical installation MUST only be performed by skilled and qualified
technical personnel such as an electrician or a technician with appropriate training). The customer
is always responsible for ensuring the suitability of the technical personnel.
Please observe the local regulations concerning the provision of electrical installations.
Correct Use
Neptronic systems and its products are designed only for humidification use. Any other application is not considered
appropriate for the intended purpose. The manufacturer cannot be made liable for any damage resulting from incorrect
use.
General Warranty
This product is subject to the terms and conditions described at http://www.neptronic.com/Sales-Conditions.aspx.

SKR Humidifier with SDU
Table of contents
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Table of contents
Foreword ………………………………………………………………………………………………………………………………..i
1. Presentation...................................................................................................................................................................3
1.1. Description of accessories supplied with the SKR humidifier with a Space Distribution Unit (SDU) module. .......3
1.2. SKR with SDU module overview............................................................................................................................3
1.3. Numbering system..................................................................................................................................................4
2. Definition........................................................................................................................................................................4
2.1. Evaporation chamber .............................................................................................................................................4
3. Characteristics...............................................................................................................................................................5
4. Mechanical installation...................................................................................................................................................6
4.1. General recommendations.....................................................................................................................................6
4.2. Positioning..............................................................................................................................................................6
4.3. Wall mounting.........................................................................................................................................................6
5. Steam connection..........................................................................................................................................................7
5.1. Typical installation ..................................................................................................................................................7
6. Plumbing connections....................................................................................................................................................8
6.1. Water supply...........................................................................................................................................................8
6.2. Drain connections...................................................................................................................................................9
7. Power supply connections...........................................................................................................................................10
8. Control panel display...................................................................................................................................................11
9. Description of the SKR control PC Boards..................................................................................................................12
P.C. Board for SKR-SDU with kit ROO and ROW..........................................................................................................12
P.C. Board for SKR-SDU with kit N.................................................................................................................................13
9.3. P.C. Board for modulating SKR-SDU with kit N.......................................................................................................14
10. Start up procedure ...................................................................................................................................................15
11. Description of operation of the SKR.........................................................................................................................15
12. Shut-down procedure...............................................................................................................................................16
13. Maintenance.............................................................................................................................................................16
13.1. General .............................................................................................................................................................16
13.2. Evaporation chamber cleaning .........................................................................................................................16
13.3. Maintenance of the SDU module......................................................................................................................17
14. Exploded View and Bill of Material...........................................................................................................................18
14.1. Exploded view of the SDU module...................................................................................................................18
14.2. Bill of Material of the SDU module....................................................................................................................18
.Exploded view of SKR..............................................................................................................................................19
14.4. Bill of Material of SKR.......................................................................................................................................19
15. Types of alarm .........................................................................................................................................................20
16. Troubleshooting guide for SDU module...................................................................................................................21
17. Electrical diagram.....................................................................................................................................................22
17.1. Electrical diagram for SKR with SDU module –Kit R.......................................................................................22
17.2. Electrical diagram for SKR with SDU module –Kit N.......................................................................................23
17.3. Electrical diagram for SKR with SDU module –Kit M-N...................................................................................24
17.4. Modulating humidifier with HRO20 ...................................................................................................................25
17.5. Modulating humidifier with HRO20 and SHR10 or SHC80...............................................................................26

SKR Humidifier with SDU
User Manual
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1. Presentation
1.1. Description of accessories supplied with the SKR humidifier with a Space Distribution Unit (SDU)
module.
The following accessories are supplied along with the ones corresponding to kit option:
1 female fitting and a braided hose to connect the water supply.
Accessories
Part #
Kit ROO
Kit ROW
Controls
Room humidity controller
HRR100
Included
Included
Window temperature sensor
OTW
----
Included
Cable
3m (10’) control cable
SP 9047
1 length included
1 length included
Kit N includes terminals for the connection of controls other than those mentioned in the above table, please
contact Neptronic for additional information about this option
1.2. SKR with SDU module overview
(Fig. 1)
SDU module option is available only along with kit R or N. Kit D or S is non-compatible because no air duct is present.
Please note that the APS supplied with standard Kit R will be substituted for an Air flow proving switch integrated into the
SDU module.
Control panel
Water level
sensor
SDU
module
Water fill
valve
Electrical
compartment
Evaporation
chamber

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User Manual
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1.3. Numbering system
2. Definition
2.1. Evaporation chamber
Assembly including the stainless steel cylinder and a cover equipped with an electric element.
(Fig. 2)
SKR - NE
Model number
Steam capacity
(3 = 3 kg/hr) M is denoting Modulating humidifier
No digit on standard unit
Kit option
3 M
E is denoting Export model
SDU
Space distribution unit
Dimple for the alignment
of the cover
Cylinder
Water coupling
High voltage
quick connect
High temperature switch
quick connect
Steam outlet

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User Manual
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3. Characteristics
(Fig. 3)
Model with
SDU
Capacity
kg/hr
(lb/hr)
Electrical Requirements
Steam outlet
diameter
mm (in)
Weight kg (lb)
Voltage
(V)
Current
(A)
Power
(KW)
Empty
With
water
SKR3E
3.0
(6.6)
230
10
2.3
35
(1-3/8")
16
(36)
23
(50)
SKR4E
3.75
(8.2)
230
12.2
2.8
35
(1-3/8")
16
(36)
23
(50)
SKR5E
5.0
(11.0)
230
16.1
3.7
35
(1-3/8")
16
(36)
23
(50)

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User Manual
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4. Mechanical installation
4.1. General recommendations
CAUTION: RISK OF ELECTRIC SHOCK. DISCONNECT THE HUMIDIFIER FROM THE ELECTRIC
SUPPLY BEFORE PROCEEDING TO THE MECHANICAL INSTALLATION.
IMPORTANT: Mechanical installation should conform to Local and National Codes.
Location: Plan a location which is easy to access in order to permit a proper inspection and servicing of
the humidifier.
Do not install humidifier where failure of the appliance could cause damage to the building structure or to
costly equipment.
This location should be well ventilated; the ambient temperature should not exceed 30C (85F).
4.2. Positioning
The front panel and the left side (electrical
compartment) should be accessible in order to
permit easy servicing of the humidifier.
Leave a minimum clearance of 0.91m (36”) from
the front panel, 0,30m (12”) from the left side,
0.15m (6”) from the right side and 0.46m (18”)
above the humidifier.
The SKR- humidifier with SDU module should be
mounted 1 to 1,2m (39” to 47”) above floor for the
installation of water supply, drain piping and
electrical connections.
4.3. Wall mounting
IMPORTANT:
1. Risk of malfunction. The humidifier must be
level.
2. Risk of overheating. Do not block the
ventilation openings located on the top,
front, sides and rear of the cabinet.
Check the solidity of the chosen support or wall
(bricks, concrete, stud partition wall, etc) on which
the humidifier will be mounted (see page 5 for the
weight of the unit).
Use the keyholes located on the back panel of the
SDU module wall mounting plate.
Drill holes for the upper anchors (holes with
eyelets) into the support or wall as per dimensions
specified in the table (fig. 4). Holes dimensions
(diameter and depth) should be in accordance with
the recommendations of the chosen anchors.
If necessary, install bolt anchors.
Insert the 2 upper screws (holes with eyelet) of a
minimum diameter of 6mm (1/4”) (screws are not
supplied).
Leave a clearance between screw heads and wall
in order to permit the mounting of the SDU wall
mounting plate.
Hang the SKR-SDU humidifier on the 2 upper
screws.
When the SKR-SDU humidifier is positioned on the
screws, insert the lower screw. Then tighten all
screws to secure the humidifier.
(Fig. 4)
(Fig. 5)
Front view
Dimensions
mm (in)
SKR-SDU
A
162 (6-3/8)
B
50 (2)
C
21 (53/64)
D
489 (19-1/4)
E
133 (5-1/4)

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User Manual
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5. Steam connection
5.1. Typical installation
(Fig. 6)
A silicone tubing (steam hose) is inserted between the steam outlet of the evaporation chamber and the
steam manifold assembly of the SDU module. Verify that the clamps are tight at both end of the silicone
tubing to prevent leaks.
SDU
MODULE
STEAM
HOSE
CLAMPS (x2)

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User Manual
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6. Plumbing connections
The SKR humidifier can operate with soft or hard water. Therefore, for normal operation, no pre-treatment of
water is necessary.
IMPORTANT: Plumbing installation should conform to Local and National Codes.
6.1. Water supply
Water inlet specifications:
IMPORTANT: Risk of malfunction, do not use demineralized water.
Inlet water pressure: 1 to 4,8 bars (15 to 70 psig)
IMPORTANT: Risk of malfunction. Do not reduce water supply flow.
Maximum temperature: 30C (85°F)
15mm (1/2'') standard copper supply water connection
To facilitate servicing, a shut off valve (not supplied) should be installed in the water supply line, close to
the humidifier.
It is recommended to install a standard strainer in the water supply line.
If required, an air chamber made of copper pipe (see fig. 7) will absorb hydraulic shock, avoiding water
hammer, when the fill valve closes. There are other standard types of air chambers commercially
available.
Please follow the steps below:
1. Connect 15mm (1/2'') copper pipe to the 15mm (1/2'') braided hose (supplied).
2. Hand tighten the swivel top 20mm (3/4'') fitting to the male threaded valve connection.
IMPORTANT: Risk of damage to the valve, do not use wrench to tighten swivel.
(Fig. 7)

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User Manual
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6.2. Drain connections
IMPORTANT: No external drain traps are required.
Drain outlet specification:
Main drain 13mm (1/2”) standard copper (evaporation chamber).
Pan drain 13mm (1/2”) standard copper.
Water drain temperature: 60C (140°F).
Two pipes minimum 25mm (1”) (by others) must be inserted over the humidifier outlet pipes
(fig.8). This will create a critical air gap at the drain connections.
NOTE: This air gap is critical for normal drain siphon operation.
(Fig. 8a)
Correct installation
(Fig. 8b)
Incorrect installation
Main drain
(evaporation chamber)
Air gap
Minimum 25mm pipe
(by others)
Drain
No drain trap required
Pan drain
SK
R
Air chamber to avoid
water hammer.
(by others)
see sect 6.1
Water supply
Shut off valve
(by others)
Main drain (evaporation
chamber) must be straight.
Do not install elbow.

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User Manual
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7. Power supply connections
CAUTION:
1. RISK OF ELECTRIC SHOCK, TURN OFF POWER AT THE EXTERNAL BREAKER/FUSED
DISCONNECT BEFORE PROCEEDING TO THE POWER SUPPLY CONNECTION.
2. To reduce the risk of electric shock, do not connect to a circuit operating at more than 150V to
ground.
IMPORTANT: The wiring to the humidifier should be done by a qualified electrician and conform to procedures,
regulations and local codes.
Ensure that the voltage required by the humidifier is the same as the available power supply.
Ensure that the size of the wire conductors is appropriate for the current required by the humidifier.
A dedicated external breaker/fused disconnect must be installed.
The ground conductor must be equipped with ring terminal and be connected the indicated location (fig. 9).
Use coppers conductors only.
Ensure that each terminal connection is properly secured.
Install the supplied strain relief bushing at the bottom of the electrical compartment for of the supply cable.
(Fig. 9)
Left side view
Terminal
connection
Ground
connection
Opening for
control cables
Strain relief bushing for passage
of the electrical cable

SKR Humidifier with SDU
User Manual
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8. Control panel display
(Fig. 10)
Front panel
"ALARM" Indicator (red)
O
flashing
One or more abnormal conditions exist.
(see section 15-Types of alarm)
O
Maintenance is required, the humidifier is OFF.
O
Normal operation.
''POWER'' Push button and Indicator (green)
O
The push button is in the ON position.
O
slow
flashing
The push button is in the OFF position and the humidifier is powered.
(1 flash every 15 seconds).
O
Humidifier is not supplied with electric power.
"FILL" Indicator (yellow)
O
Water supply valve is open.
O
Water supply valve is closed.
"STEAM" Indicator (green)
O
Humidifier is producing steam at 100% capacity
O
flashing
Modulating humidifier only:
Humidifier is modulating steam output according to the demand.
Frequency of flashing is in proportion to the percentage of steam output.
O
Humidifier is not producing steam.
''DRAIN'' Push button and Indicator (yellow)
O
Humidifier is in automatic or manual drain mode.
Press ‘’DRAIN’’ push button to stop an on-going drain cycle.
O
Drain mode is off.
''FAN'' Indicator (green)
O
The contact to activate the ventilation system fan is closed.
O
The contact to activate the ventilation system fan is open.

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User Manual
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9. Description of the SKR control PC Boards
The Printed Circuit Board is equipped with an advanced microprocessor, which controls all humidifier
functions.
IMPORTANT: Certain features on the SKR pc board cannot be used when the humidifier is integrated along
with a SDU module.
P.C. Board for SKR-SDU with kit ROO and ROW
TB7
High voltage terminal blocks L, N and power supply to heating
element.
TB1
Power supply to SDU fan.
TB3
Dry contact (TB3) for remote alarm annunciation.
(1A, 24 Vac).
TJ1
Telephone jack Terminal (TJ1) to connect Room humidistat
(HR).
TB6
Terminal (TB1) to connect the window temperature sensor
(OTW).
DS1
Dip switch (DS1) settings:
(Fig 11b)
Dip switch setting
DS1: Dip switch #3 is not used.
Note: Depending on the local water conditions, service of the
humidifier may be required prior to the ''service required'' alarm
setting (see section 14, Maintenance of the SKR Installation
instructions & user manual).
(Fig. 11)
P.C. Board top view
ON
1 2 3
Drain every 2hours of
operation
''Service required''
alarm appear after
750 hours of operation
ON
1 2 3
Drain every 6hours of
operation
''Service required''
alarm appear after
1500 hours of
operation
TB1 TB3
JP3
F3
F2
1 2 3 4
TB7
DS1
ON
1 2 3
JP8
FAN-PROOF
Fuse
TB6
Safety HV cover
TJ1

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User Manual
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P.C. Board for SKR-SDU with kit N
TB7
High voltage terminal blocks L, N and power supply to
heating element.
TB1
Power supply to SDU fan.
TB3
Dry contact (TB3) for remote alarm annunciation.
(1A, 24 Vac).
TB5
Terminal to connect the humidistat or Building Automation
System (see fig.16).
DS1
Dip switch (DS1) settings:
(Fig 12b)
Dip switch setting
DS1: Dip switch #3 is not used.
Note: Depending on the local water conditions, service of
the humidifier may be required prior to the ''service
required'' alarm setting (see section 14, Maintenance of
the SKR Installation instructions & user manual).
(Fig. 12)
Top view
ON
1 2 3
Drain every 2hours of
operation
''Service required''
alarm appear after
750 hours of operation
ON
1 2 3
Drain every 6hours of
operation
''Service required''
alarm appear after
1500 hours of
operation
TB1 TB3
JP3
F3
F2
1 2 3 4
TB7
DS1
ON
1 2 3
JP8
FAN-PROOF
Fuse
TB5
Safety HV cover

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User Manual
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9.3. P.C. Board for modulating SKR-SDU with kit N
TB7
High voltage terminal blocks L, N and power supply to
heating element.
TB1
Terminal to SDU Fan (TB1).
TB3
Dry contact (TB3) for remote alarm annunciation.
(1A, 24 Vac).
TB5
Terminal to connect to an external cut off dry contact
(see fig. 17).
TB6
Terminal to connect the humidistat or Building Automation
System (see fig.17).
DS1
Dip switch (DS1) settings:
(Fig 13b)
Dip switch setting
DS1: Dip switch #3 is not used.
Note: Depending on the local water conditions, service of
the humidifier may be required prior to the ''service
required'' alarm setting (see section 13, Maintenance).
(Fig. 13)
Top view
ON
1 2 3 4
Drain every 2hours of
operation
''Service required''
alarm appear after
750 hours of operation
No function attributed
ON
1 2 3 4
Drain every 6hours of
operation
''Service required''
alarm appear after
1500 hours of
operation
No function attributed
2-10 VDC
control demand signal
0-10 VDC
control demand signal
TB1 TB3
JP3
F3
F2
1 2 3 4
TB7
DS1
JP8
FAN-PROOF
Fuse
TB5
Safety HV cover
Dip switches
ON
1 2 3 4
TB6

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User Manual
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10. Start up procedure
Follow this start-up procedure to avoid improper system operation:
1. Ensure that electrical and plumbing connections have been done in accordance with the instructions in this
manual.
a) Remove the humidifier cover.
CAUTION: RISK OF ELECTRIC SHOCK, ENSURE THAT THE POWER IS TURNED OFF BEFORE
REMOVING THE COVER.
b) Ensure that the control wiring has been made in accordance with the instructions in this manual.
c) Ensure that dip switches (section 9, DS1) are correctly set.
d) Verify that the drain connections are connected to an open main drain of sufficient diameter.
e) Re-install the humidifier cover.
2. Open the water shut off valve (external to the humidifier).
3. Turn on the power to the humidifier at the breaker/fused disconnect. The ''POWER'' indicator, located on the
control panel, will flash.
4. Press the ''POWER" push button located on the control panel. The ''POWER" indicator will stay on
continuously.
5. Perform a manual cleaning cycle:
a) The fill cycle is activated automatically when the evaporation chamber does not contain water.
b) When the ''FILL'' indicator is off, press the “DRAIN” push button.
c) The ''DRAIN'' indicator will come on and the water will drain from the evaporation chamber.
d) The evaporation chamber will fill with water and drain again.
e) When the ''DRAIN'' indicator turns off, press on the ''POWER" push button.
f) Repeat steps ''b'' through ''e'' one more time to ensure proper cleaning of the evaporation chamber.
6. Your humidifier is now fully operational. No other action is necessary; your SKR humidifier will produce
steam upon demand from control(s).
11. Description of operation of the SKR
Press the ''POWER'' push button (if the indicator is flashing) to start the humidifier (''POWER'' indicator will
light continuously). If the evaporation chamber does not contain water, the fill cycle is activated
automatically (''FILL'' indicator is on).
If there is no demand from the humidity controller, the humidifier is in a standby mode (''STEAM'' indicator is
off).
On a demand of humidity, the contact to activate the ventilation system fan closes (''FAN'' indicator is on)
and the relays close to power the electric element in the evaporation chamber (''STEAM'' indicator is on).
The water in the evaporation chamber will start to boil and evaporate. The steam is released through the
opening in the cover of the evaporation chamber. The steam will travel in the flexible steam hose and
disperse into the space by fan assembly of the SDU through the steam manifold.
During the evaporation sequence, a certain amount of water is evaporated. The water supply valve will
open to replenish the water in the evaporation chamber.
Depending on the selected drain period (section 9, DS1-1), the water in the evaporation chamber will be
drained (''DRAIN'' indicator is on) to renew the water and to evacuate the minerals inside the evaporation
chamber.
The SKR operates at full capacity until the programmed humidity level set point is reached. When the set
point is reached, the humidifier will revert to standby mode. The contact to activate the fan assembly will
remain closed for a period of four minutes after steam production has stopped.
When the humidity level is below the set point, the humidifier will produce steam again. If there is no
humidity demand for a period of more than 72 hours, the humidifier will drain the water from the evaporation
chambers automatically and go into standby mode

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User Manual
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12. Shut-down procedure
During seasonal shut down, the humidifier should be placed out of service.
1. Press ''DRAIN" push button to empty the water from the evaporation chamber, the ''DRAIN'' indicator will be
on.
2. Once the cycle has ended, the ''DRAIN'' indicator will turn off. Close the shut off valve (external to the
humidifier) on the water supply line.
3. Open the main power breaker/fused disconnect switch to the humidifier.
13. Maintenance
13.1. General
IMPORTANT: Failure to perform the required periodic maintenance will void the warranty.
The required cleaning frequency can vary from every 2 months to once a year depending on local water
conditions.
The SKR humidifier is equipped with an internal operating hour counter and a ''service required'' alarm.
Depending on the local water conditions, service of the humidifier may be required prior to the ''service
required'' alarm setting (section 9, DS1-2).
The routine service is a cleaning of the evaporation chamber.
13.2. Evaporation chamber cleaning
CAUTION: RISK OF BURN. THE EVAPORATION CHAMBER AND ITS CONTENTS CAN BE EXTREMELY
HOT, CHECK TEMPERATURE BEFORE HANDLING.
1. Cooling down and draining of the evaporation chamber.
a) Press ''DRAIN'' push button on the control panel. The humidifier will initiate a drain cycle.
The ''DRAIN'' indicator will turn on.
b) The ''DRAIN'' indicator is on and the water is drained from the evaporation chamber.
c) The evaporation chamber will refill with water and drain again.
d) When the ''DRAIN'' indicator turns off, the ''POWER'' indicator will begin to flash.
e) Check the temperature of the evaporation chamber. If it is cool enough go to step #2 below,
otherwise repeat draining of the evaporation chamber (step #1) until is cold enough.
2. Shut down of the electrical supply.
CAUTION: RISK OF ELECTRIC SHOCK, TURN OFF POWER AT THE EXTERNAL
BREAKER/FUSED DISCONNECT BEFORE SERVICING.
a) Remove the cover of the SKR Humidifier.
3. Disconnecting the heating element.
a) Unscrew the high voltage quick connect (see fig. 2), located on the right side of the electrical
compartment.
4. Disconnecting the high temperature switch.
a) Disconnect the high temperature switch quick connect (see fig. 2).
5. Disconnecting the steam hose and the water pipe.
a) Loosen clamp on the steam hose connection.
b) Remove the steam hose from the top of the evaporation chamber.
c) Unscrew the water piping coupling located on the lower right hand side of the evaporation chamber.
6. Removing the evaporation chamber.
a) Remove the evaporation chamber from the humidifier cabinet.
7. Opening the evaporation chamber.
a) Unfasten the 3 latches located around the evaporation chamber.
Caution: Risk of injury, latches are tight. It is recommended to use pliers or a screwdriver to
unfasten the latches.
b) Remove the cover from the evaporation chamber.
c) Do not misplace the gasket located between the cover and the cylinder.

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User Manual
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8. Cleaning the evaporation chamber.
a) Pour out any remaining water and scale from the bottom of the evaporation chamber
b) Clean out the remaining scale, use a non-metallic brush and water. Some vinegar or any weak acid
for cleaning stainless steel may be required.
IMPORTANT: The use of wire brush or any non-recommended acid will void the warranty.
c) If the amount of scale to be removed is significant, the service required alarm setting and/or the
drain rate (section 9, DS1-1) may be set too high for the local water conditions.
Too much scale may impair the normal operation of the humidifier or damage it. In this case,
increase the frequency of maintenance as necessary.
9. Cleaning the electric element and cover.
a) The cover of the evaporation chamber and element will, in general, not require cleaning.
However, if cleaning is required, proceed as per the cleaning of the evaporation chamber.
IMPORTANT: The use of wire brush or any non-recommended acid will void the warranty.
10. Checking the gasket
a) Check the gasket. The gasket should not be cracked.
The gasket must be replaced a minimum at every second maintenance of the evaporation chamber
or after one year of operation. Replace more frequently if required.
11. Reassembling the evaporation chamber.
a) Rinse out the cylinder and the cover with water.
b) Place the gasket inside the cover before installing the cover on the evaporation chamber.
c) Align the dimple on the cover with the latch located nearest to the water drain/fill coupling (fig.2).
d) Tighten the three latches around the cover.
e) Replace the evaporation chamber in the humidifier.
f) Tighten the water drain/fill coupling.
g) Replace the steam hose on the outlet of the evaporation chamber and secure steam hose with the
clamp.
h) Reconnect the high temperature switch connector and the high voltage connector of the heating
element.
CAUTION: RISK OF OVERHEAT AND FIRE, MAKE SURE THE HIGH VOLTAGE CONNECTOR
IS PROPERLY LOCKED.
i) Replace the cover on to the humidifier and lock it.
12. Start-up of the humidifier.
a) Close the main power breaker/fused disconnect switch to the humidifier.
Reset of the operating hours to zero: Press ''POWER'' push button to turn OFF the humidifier, if
necessary, then press and hold the ''POWER'' and ''DRAIN'' push buttons for ten seconds
(section 15-Types of alarm, Reset).
b) Press the “POWER” push button. The “POWER” indicator on the control panel will light.
c) The humidifier will go into a fill cycle; the ''FILL'' indicator will be on.
d) If there is a humidity demand, the humidifier will produce steam.
13.3. Maintenance of the SDU module
The SDU module is maintenance free. No maintenance is required.

SKR Humidifier with SDU
User Manual
www.neptronic.com 18
14. Exploded View and Bill of Material
14.1. Exploded view of the SDU module
(Fig. 14a)
14.2. Bill of Material of the SDU module
Item
Description
Model
Part number
A
SDU manifold
SKR-3E / 4E / 5E
SW PIPESDUR-ASSY
B
Fan assembly
SKR-3E / 4E / 5E
SP 3012
C
Air pressure switch
SKR-3E / 4E / 5E
SP PSA-01
D
Pitot tube assembly
SKR-3E / 4E / 5E
SW SDUR-PITOT
E
SDU Grill
SKR-3E / 4E / 5E
SP SDUR-GRILL
F
Silicone tubing
SKR-3E / 4E / 5E
SP 1026
G
SDU cabinet
SKR-3E / 4E / 5E
SP 9005
H
SDU cover
SKR-3E / 4E / 5E
SP 9004
I
SDU Grill support
SKR-3E / 4E / 5E
SP9005-6
G
B
I
D
C
A
F
H
E

SKR Humidifier with SDU
User Manual
www.neptronic.com 19
.Exploded view of SKR
(Fig. 14b)
14.4. Bill of Material of SKR
Item
Description
Model
Part number
A
Evaporation chamber cylinder
SKR-3E / 4E / 5E
SW SKRCONT-ASSY
B
Evaporation chamber cover
SKR-3E / 4E / 5E
SP 9012-M
C
Evaporation chamber gasket
SKR-3E / 4E / 5E
SP 9030
D
Heating element
SKR3E
SE 5991
SKR4E
SE 5992
SKR5E
SE 5993
E
Heating element gasket
SKR-3E / 4E / 5E
SP 1005
F
High temperature switch
SKR-3E / 4E / 5E
SP 3035
G
Water level sensor assembly
SKR-3E / 4E / 5E
SW SKRLEV-ASSY
H
Water level sensor tube
SKR-3E / 4E / 5E
SP 1025
I
Water fill valve
SKR-3E / 4E / 5E
SP 6004
J
Drain pipe assembly
SKR-3E / 4E / 5E
SW SKRDRAIN-ASSY
K
Main plumbing assembly
SKR-3E / 4E / 5E
SW SKRPIPE-ASSY
M
Main PC board kit R
SKR-3E / 4E / 5E
NW SKRESMAINSS
Main PC board kit N–ON/OFF
SKR-3E / 4E / 5E
NW SKRESMAIN-NSS
Main PC board kit N–Modulating
SKR-25M/ 30M/ 40M
NW SKRES-M-NSS
N
SKR-TRIAC PC board (option M)
SKR-3EM/ 4EM
NW SKRET-2SS
SKR-5EM
NW SKRET-3SS
SKR-TRIAC PC board
(option L or ML)
SKR-3E / 4E
NW SKRL-2SS
SKR-5E
NW SKRL-3SS
N
Option M or L
only