Armstrong EHU-750 Series User manual

Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
752, 753, 754, 755
Technical manual

2 Pictures for illustrating purposes only
Safety information 3-4
Accreditation 5
RoHS declaration 6
Delivery contents 7
Dimensions & weights 8
Humidifier component part overview 9
Wall installation
Installation steps 10
Step 1 - Placing and wall attachement 11-12
Step 2 - Water connection 13
Step 3 - Steam pipe positioning 14 to 21
Step 3 - Optional temperature control system 22
Step 4 - Condensate outlet 23
Step 5 - Electrical connections 24 to 39
Step 6 - Control connection 40
Setting up 41
System management
Humidifier status menu 42-44
Humidifier configuration menu 45
Configuration changing menu 46-48
Maintenance
Cylinder maintenance guide 49
Precaution 50
Service & alerts 51 to 53
Main board changing 54
Steam cylinder cleaning 55
Valves maintenance 56-57
Spares lists 58 to 61
SERIES EHU-750 HUMIDIFIER
Table of Contents

3Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Safety information
IMPORTANT
Please read, heed and follow the enclosed safety information and the
warning labels inside the humidifier before installation or maintenance.
Warnings&safetysymbols
Warning : This symbol is used to designate a danger of injury or potential
damage to the system.
Caution : High voltages are present inside the humidifier. All works concerned
with the electrical installation must be carried out by skilled and qualified
personnel.
Caution : Danger of scalding ! The EHU-750 humidifier generates steam
during operation and therefore surfaces and pipe-work become very hot.
Ensure that equipment not sustaining high temperatures be kept away.
Warning : the end user should ensure that the equipment be disposed of
according to the local prevailing regulations.
Deliveryandstorage
Any loss or damage during delivery should be reported to carrier by registered letter
within 3working days and be advised to Armstrong International sa.
(« Armstrong® ») or to authorized dealer.
It is recommended that the EHU-750 humidifier be kept in its transit packaging for as
long as possible prior to maintenance. If the humidifier is to be put into storage prior to
installation, it must be stored under cover and protected from physical damage, dust,
frost, rain and humidity. More than 6 months storage is not recommended.

4 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Safety information
GENERAL
This manual contains all details necessary for the planning and installation of the EHU-750
humidifier. In addition commissioning and maintenance details are included.
The manual is intended for use by engineers and properly trained technical personnel.
Maintenance, servicing or repair work must only be carried out by suitable skilled and
qualified personnel, the customer must be responsible for ensuring their suitability.
Any risks or hazards, especially when working from ladders or towers should be identified by
a skilled and Health and Safety representative and effective control measure put in place.
No liability will attach to the Distributor if any damage, injury or accident is attributable to
inattentive, inappropriate, negligent or incorrect operation of the machinery whether or not
caused deliberately. Always isolate all electrical and water supplies before commencing any
maintenance.
Every effort has been made to ensure details contained in this manual are correct, however,
in view of the wide range of conditions experienced in air handling systems, the information
provided should only be used as a guide. Please contact your Agent if any doubt.
Correctuse
EHU-750 humidifiers are ONLY intended for use with air handling systems or direct air
humidification. ANY OTHER APPLICATION IS NOT CONSIDERED USE FOR THE
INTENDED PURPOSE. THE MANUFACTURER CANNOT BE MADE LIABLE FOR ANY
DAMAGE RESULTING FROM INCORRECT USE.
Water
Series EHU-750 humidifiers are designed to be used with mains, demineralized R/O or
softened water. On no account attempt to introduce any other fluid or chemical into the
system. Water supply should not exceed 6.0 bar and installation should comply with local
regulations. If the water pressure exceeds 6.0 bar, a water regulator valve must be used.
Electricity
All work concerned with electrical installation MUST only be performed by skilled and
qualified technical personnel (eg electrician or technicians with appropriate training). The
customer MUST be responsible for ensuring their suitability.
It is the duty of the installer to ensure that suitable sized cables and MCB protection is
provided. Please observe the local regulations concerning the provision of electrical
installations.
Warranty
A one year warranty term—cost and labor—is applicable to the parts of the EHU-750 to the
exception of the usual consumable parts (valves, cylinders or parts of cylinders) provided our
recommendations of use & maintenance have been adhered to. Failure to specify and fit
original parts and accessories will invalidate our warranty.
NOTE
The manufacturer’s policy is one of continuous research and development. He therefore
reserves the right to amend without notice the specifications given in this document.
The photographs are for illustrating purposes only.

5Pictures for illustrating purposes only
APPLIEDDIRECTIVES
Electromagnetic Compatibility Directive : 89/336/EEC, 2014/30/UE
Low Voltage Directive : 73/23/EEC, 2014/35/UE
Machinery Directive : 98/37/EC Amending Directive 89/392/EEC
Standard(s) to which Conformity is declared :
EN 61000-6-3 : Electromagnetic compatibility generic requirements (residential, commercial and light indus-
tries) EN 55022 class B conducted and radiated emission limits)
EN 61000-6-2 : Electromagnetic compatibility (EMC) – Generic standards –Immunity for industrial environ-
ments; EN 61000-4-3 : Radiated, radio frequency, electromagnetic field immunity test.
EN 61000-4-6 : Immunity to conducted disturbances induced by radio frequency fields
EN 61000-4-4 : Electrical fast transient/burnt immunity test
EN 61000-4-5 : Surge immunity test
EN 61000-4-2 : Electrostatic discharge immunity test
EN 60204-1 : Safety of machinery – Electrical Equipment of machines – Part 1 : General requirements
EN 292 Parts 1 & 2 : Safety of machinery basic principle mechanical design.
Manufacturer’s Name and Address
ARMSTRONG INTERNATIONAL SA
DEVATEC SAS
Bd des Frères Rousseau
76550 Offranville - FRANCE
Authorised Representative
Type of equipment
Series EHU-750 humidifier
Model Name (s) & Series:
EHU-750
Year of Manufacture
2001
We the undersigned, hereby declare that the equipment specified
above conforms to the above Directive(s) and Standard(s).
Mr FRAMBOT Jean-François
Managing Director
Date : 01.06.2016
SERIES EHU-750 HUMIDIFIER
Product accreditation

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SERIES EHU-750 HUMIDIFIER
RoHS declaration
Armstrong International sa
devatecsas
Bd des Frères Rousseau
76550 Offranville
France
Confirms that the series EHU-750 steam humidifier is manufactured in compliance with
the European regulations 2002/95/EU (RoHS).
This guideline regulates after July 1
st 2006 the use of mercury, cadmium, lead (soldering
processes), chrome VI as well as PBB and PBDE. EHU-750 steam humidifiers manufactured
previously to this date may contain above materials.
Name : MINFRAY Jean-Marie
Position : R&D Engineer
Date : 05.06.2008
Signature:

7 Pictures for illustrating purposes only
Whatisinthebox:
1. One EHU-750 steam humidifier supplied with one, two or three disposable or cleanable cylin-
der(s) according to the purchased model together with an on/off or proportional control.
2. One 500mm long flexible hose with 3/4”thread (with washers) for tap water connection.
3. Ø 25 mm drain hose :
EHU-752 & 753 (1 cylinder ) : 1 m. long
EHU-754 (2 cylinders) : 2 hoses of 1 m. long and 1.2 m. long respectively
EHU-755 (3 cylinders) : 3 hoses of 1 m. long, 1.2 m. long and 1.8 m. long
4. Hose clamps :
EHU-752 & 753 : 3 clamps (2 pieces for the steam hose & 1 piece for the drain hose)
EHU-754 : 6 clamps (4 pieces for the steam hoses & 2 pieces for the drain hoses)
EHU-755 : 9 clamps (6 pieces for the steam hoses & 3 pieces for the drain hoses)
SERIES EHU-750 HUMIDIFIER
Delivery contents
1
Any loss or damage during delivery should be reported to carrier by registered letter
within 3 working days and be advised to Armstrong®or to authorized dealer.
It is recommended that the EHU-750 humidifier be kept in its transit packaging for as
long as possible prior to maintenance. If the humidifier is to be put into storage prior to
installation, it must be stored under cover and protected from physical damage, dust,
frost, rain and humidity. More than 6 months storage is not recommended.
3 2 4
OPTIONS
Remote information board
Filling cup plateform
400/230V transformer
(for installation without neutral)
Draining water cooling kit
Sanitation system
Power circuit breaker
Protective enclosures
(sizes as per models)
Humidifier ground holders
ACCESSORIES
Stainless steel holed steam distributing pipes
Steam and condensate hoses
Room ventilation units
Room or duct humidity sensor
Humidistat
ExpressPack

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SERIES EHU-750 HUMIDIFIER
Dimensions & Weight
469
A
533,4
B
214,5
C
300 275
262
414
D
G
357
357
G
E414,31
E
271,5
D
402
552
275 382
521
401,69300,61 381,78275,22275,22
G
E
G
E
DD
H
F F F
HH
Dimensions in mm Weight in Kg
Humidifier Water
inlet Steam outlet
Steam
outlet
spacing
Drain
outlet
Drain
outlet
spacing Empty Opera-
ting
Model A B C D E F G H
EHU-752: 1 SMCYL 475 540 217 215 355 355 15 23
EHU-753: 1 LG CYL 550 680 272 270 410 410 22 37
EHU-754: 2 LG CYL 845 680 272 270 400 300 400 300 30 60
EHU-755: 3 LG CYL 1075 680 272 270 380 275 380 275 45 90
EHU-752
1 small
cyl.
EHU-754
2 cylinders EHU-755
3 cylinders
EHU-753
1 large
cyl.
 SM CYL = small cylinder, LG CYL = large cylinder

9 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Humidifier component parts
EHU-752&753humidifiersplitview
20
15
5
6
17
21
18
19
16
8
14
11
13
10
12
9
24
22
23
7
2
3
3
1
1 Steam hose
2 Water feed hose 12x16mm
3 Hose clamp 16x25mm
4 Overflow water hose 18x22m
5 On/off rocker switch
6 Stand-by lamp
7 Grommet
8 Drain cup (upper)
9 Water inlet valve
10 LCD display board
11 Remote information board (option)
12 Power contactor
13 Main circuit board
14 Filling cup
15 Drain valve
16 Cylinder strainer
17 Steam cylinder
18 Stainless steel electrode plate
19 High water level electrode
20 High water level electrode cable
21 Electrode live power cable
22 Cylinder water feed hose 18x22 mm
23 Flexible water feed hose 3/4”F
24 Hose clamp 12x22 mm
4

10 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation steps
All works concerned with electrical installation must be carried out by a skilled and
qualified personnel.
Please read, heed and follow the enclosed information for the installation of the
humidifier and the steam, water and electrical networks.
For further technical assistance, feel free to call Armstrong®.
Failure to adhere to manufacturer’s installation recommendations will invalidate
your warranty.
Steps
Setp 1 - Placing and wall attachment
Step 2 - Water connection
Step 3 - Steam pipe positioning
Step 4 - Condensate outlet
Step 5 - Electrical connection
Step 6 - Control connection
Step 2
Step 3
Step 4
Steps 5- 6
Step 1
Step 4

11 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 1
Installationtips:
The humidifier should be operated within 5°C and 40°C in a room with less than 80% of
humidity.
When in operation, the rear panel becomes hot (60°C) so do not hang the humidifier on a heat
sensitive surface.
The Armstrong®humidifiers have been developped to be hanged on wall. Before installation,
make sure that the surface material is strong enough to hold the humidifier.
The best performances of the humidifier are achieved when the steam discharge is made at
short distance from the humidifier (see after page n°20).
Consider free space around the humidifier to allow easy access for maintenance purposes
(s.a. here under sketches).
Howtoinstallthehumidifieronwall
600 mm 600 mmmini
500 mm mini
1000 mm mini
1250 mm

12 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 1
Nota:
Use installation equipment and material appropriate to the surface on which the unit
should be hanged .
The dimensions mentioned underneath are for cabinets without doors.
A
DETAILA
R4
R6
10
20
Drilling distances in mm
Model A B C D E F G H
EHU-752: 1 SMCYL 21 110 425 40 21 425 385
EHU-753: 1 LG CYL 41 110 467 40 21 507 525
EHU-754: 2 LG CYL 41 110 760 40 21 800 525
EHU-755: 3 LG CYL 41 110 455 535 40 21 1030 525
40
507 1030
467
41
110 110
41
40
21
41 41
455 535
O6
2x
O6
2x
AAAA
BB
CCD
G
G
F
EE
21
F
525
H
525 H
Method:
Mark and drill the mounting holes for 6 mm screws (s.a. the drilling distance table) :
EHU-752, 753 & 754 with 1 or 2 cylinders : 4 mounting screws
EHU-755 with 3 cylinders : 5 mounting screws
Insert pegs in holes and the upper screws. Allow about 10 mm for hanging the cabinet.
Hang the cabinet and level it vertically and horizontally. Screw up the upper screws and
then screw up the lower screws.
Detail of
hanging hole
Installationonwall
EHU-752, 753 & 754
1 & 2 CYL EHU-755 3 CYL
 CYL = cylinder
 SM CYL = small cylinder, LG CYL = large cylinder
 Optionnal support legs to be used for ground installations when a wall installation cannot be
made: - Part nb 999989 for EHU-752 (small single cylinder model)
- Part nb 999992 for EHU-753 (large single cylinder model)
- Part nb 999990 for EHU-754 (two cylinder model)
- Part nb 999988 for EHU-755 (three cylinder model)

13 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 2
Recommendations:
The operating principle of the electrode steam humidifier is the electrolyse
where an electrical current runs through stainless steel electrode plates
immersed in water made conductive by the mineral salts it contains.
The series EHU-750 humidifier can produce steam from 3 water qualities
having the following characteristics :
Town water or raw water : the water TH should be between 0 and 40°
French grade for a conductivity between 350µS and 1000µS/cm (Micro
Siemens per centimetre).
Softened water: water treated by sodium/calcium permutation on resins.
The titration value TH should be kept as constant as possible and between
0° and 2°.
It is essential that the salt maintenance of softeners be programmed for the
water volume consummed in order to prevent an excessive salt
concentration to humidifer once the regeneration cycle is finished (please
refer to the softener’s user manual). Duplex softeners are best suited to
your humidifier in this regard. In doubt, please consult Armstrong®.
Demineralised water: this is a water treatment by reverse osmosis or
running through resins.
The EHU-750 humidifier can work with demineralised waters having a
minimum water quality of 30µS/cm. A tea spoon of bicarbonate of soda
must be added on start-up to initiate steam production.
Nota Bene : on starting up the humidifier, the nominal steam production is
reached after one or two days when using low conductivity waters.
This period can be shortened by adding a tea spoon of salt that has been
firstly diluted in 1/4 litre of water. Pour the mixture into the filling cup.
Caution : do not touch the water - Risk of electric shock.
THIS MUST BE CARRIED OUT BY A SKILLED AND QUALIFIED
PERSONNEL.
No chemical agent whatsoever (chlorine, disinfectant, ozone… ) must
be added to the water. Some water qualities may generate foam that
can disturb the correct functionning of the humidifier. If this occurs to
your humidifier, please refer to Armstrong®for further assistance.
WATERCONNECTION
Recommendationsonwatertapping:
A fresh mains cold water service should be used to supply the unit. The
water pressure should not exceed 6 bar and should not be inferior to 1 bar
with a temperature less than 40°C. In case the water pressure exceeds 6
bar, a water regulator valve must be used.
The water supply connection is on the bottom of the unit. All the EHU-750
are supplied with a 500 mm long water inlet hose with a 3/4” female
connection to the cold water supply. A check valve should be located on
the mains and cold water service connection to the unit.
The series EHU-750 humidifier uses water to produce steam so
leakage may happen causing potential damage. If an installation in
false ceiling or above prime rooms such as museum, exhibition or
laboratory rooms is considered, ensure that the floor below the
humidifier is constructed from waterproof materials (with draining
facilities) to withstand any water spilling during servicing or if a
b a
The water level must be
between « a » and « b » for
the maximum capacity of
the cylinder.

14 Pictures for illustrating purposes only
O25 OU 40
8
1
2
590
L
50
2
2
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
Steam from the cylinder enters the duct via a steam distribution pipe. In order to obtain
optimum performance of the humidifier, it is recommended that these instructions be adhered to as
far as possible.
There are two steam inlet diameters available : Ø 25 mm and Ø 40 mm
STEAMDISTRIBUTIONPIPE
Steamdistributionpipeselectiontable
The number of distribution pipes and the diameters depend on the humidifier model.
•SM CYL = small cylinder, LG CYL = large cylinder
To get the best steam distribution, select the longest possible distribution pipe to fit the duct.
Standard distribution pipes are available on either diameter in 110, 290, 590, 790, 1000, 1250
and 1500 mm long.
1Steam inlet
2Condensate drain
or 100

15 Pictures for illustrating purposes only
% RH1 inlet air
510 20 30 40 50 60 70
% RH2 outlet air Minimum humidification distance « D » in m.
40 0.9 0.8 0.7 0.5 - - - -
50 1.1 10.9 0.8 0.5 - - -
60 1.4 1.3 1.2 10.8 0.5 - -
70 1.8 1.7 1.5 1.4 1.2 10.7 -
80 2.3 2.2 2.1 1.9 1.7 1.5 1.2 0.8
90 3.5 3.4 3.2 2.9 2.7 2.4 2.1 1.7
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
Evaporationdistanceorvaportrail«D»
A certain length is required so that the steam coming out of the steam distribution pipe be
absorbed by the air. All along this length, descrided as the evaporation distance, the steam can still
be seen in the airflow as a mist which can condensate in water against any obstacle if placed within.
To prevent condensation, this evaporation distance should be calculated before positioning the
steam distribution pipe.
Howtocalculatetheevaporationdistance«D»
In order to determine the evaporation distance, the attached calculation table can be used :
HR1 = relative humidity of air before humidification in %.
HR2 = relative humidity of air after humidification in %.
D minimum humidification distance in meters (m).
This calculation table is to be used for temperatures between 20 and 25 °C. For lower
temperatures, please consult factory.
Minimaldistancesofhumidification
The steam distribution pipes should be positioned as per the following indications and in
consideration of your Air Handling Unit. Please consider these distances as minimum
POSITIONINGOFTHESTEAMDISTRIBUTI0NPIPE
Before / after fan before / after heater/filter
D D 1.5 x D 5cm
2,5 x D before thin particule filter

16 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
Before a junction before an air opening before a humidity sensor
D
D
5 x D
0,5 x D
Before / after a constriction before an expansion before a bend
D
0,5 x D
A high humidity limit humidistat must be installed in the duct to stop the humidifier in case the
level of humidity exceeds the preset value.
In case the recommended distances cannot be met, please contact Armstrong®or their
authorized agent for an alternative solution.
If accurate values cannot be reached, a distance of 2 m. should be considered as a minimum
distance between pipes & obstruction and 3 / 4 m. before sensor or humidistat.
A humidity sensor located near the steam pipe will cause the unit to malfunction. The power
contactor will close and open rapidly causing the contacts to heat up involving an early wear.

17 Pictures for illustrating purposes only
11
1
1
660H> mm
H3
H2
H1
H2
410H > mm
19,611
H3
H2
1
H1
11
1
H3
H2
H1
480H> mm
550H > mm
11
1
H1
H2
H2
1
H3
270H > mm
1
H3
8,51
H1
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
STEAM DISTRIBUTIONPIPEPOSITIONING
Please meet the following dimensions and spaces according to your configuration. For further
information, please contact Armstrong®or their authorized agent.
H1 = 110mm = Minimum height between the duct floor and the axle of the steam pipe.
H2 = 140mm = Minimum distance between two pipes.
H3 = 160mm = Minimum height between the duct top and the axle of the steam pipe.
The H3 distance can be 80 mm at the shortest in case the steam pipe is installed at
an angle of 30°.
The arrow shows the direction of the air flow.

18 Pictures for illustrating purposes only
1
D
15°
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
STEAMDISTRIBUTIONPIPEPOSITIONING
In vertical ducts where the air flow is
upward or downward, the steam distribution
pipe(s) must be tilted by 15° sideways.
590
47,2
d/2
d
30° à 45°
1
H3
In duct with limited height, the distribution pipe(s) can be
tilted by 30° to get the 80 mm minimum height.
D = Humidification distance
d = Duct diameter
EXPRESSPACK
The Armstrong®ExpressPack is a
bespoke steam humidification system made to suit
your your configuration and ready to install in a
ventilation duct.
It permits to have vapor trails (evaporation
distance) as short as 600 mm. For further
reference, please contact Armstrong®or their
authorized agent.
30°

19 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
For ensuring the best steam distribution possible, we would recommend to install the steam
pipes in either diameter as per the two methods described underneath.
INSTALLATION
O5
4 X
100
140 124
84
8
8
3690
Howtoinstallonaduct(particular)
Howtoattachthepipeend (insidetheduct) -Particular
O5
The end of the steam pipe should be attached to the duct with a threaded rod of Ø 5 mm
going from the dedicated hole of the fixing plate to the outside of the duct and attached
by a couple of nuts (method 1). A rail attached to the inner side of the duct can also be
used - a 5mm bolt and nut are used to settle the pipe on the rail (method 2).
Your steam pipes must be screwed
onto the ventilation duct by the
fixing plate with a set of 4 bolts and
nuts of Ø 5 mm.
The length of the bolts will be
according to the thickness of the
ventilation duct.
The steam pipe must be at
level with the duct.
Threaded rod
Method 2
Method 1
Rail

20 Pictures for illustrating purposes only
SERIES EHU-750 HUMIDIFIER
Installation - Step 3
1. We would recommend to use the steam hose from Armstrong® supply .
NB : when the humidifier is started up for the first time, a smell of burning may be smelt
especially when brand new hoses are installed. This is normal and will eventually dispel.
2. Steam hose selection :
•SM CYL = small cylinder, LG CYL = large cylinder
3. The EHU-750 humidifier can be used with pressure ducts (P) having the following
characteristics :
·If P is inferior to 150mm CE (Water column) i.e. 1470Pa.
·If P is between 150mm CE et 300mm CE, our optional filling cup plateform must be
used
4. Please adhere to the recommendations given underneath for the installation of the steam hose
according to one of the shown examples, the most suited to your installation. A set of hose
clamps are supplied for ensuring a correct installation.
The humidifier should be located within 3 m. of the steam distribution pipe. If the distance is
superior to 3 m., insulated steel or copper pipe of a slightly larger diameter must be used.
STEAMOUTPUT
Radius of bend for steam hose :
- Ø 25 mm hose = 250 mm minimal radius
- Ø 40 mm hose = 400 mm minimal radius
Example a
Example b
D 8mm condensate hose to
drain
500 mm min.
500 mm min.