IWAKI EHN-B21SH User manual

EHN-SH
Instruction Manual
IWAKI
Electromagnetic Metering Pump
Read this instruction manual before use of product

- 1 -
Types of Symbols
Indicates a prohibited action or procedure. Inside or near this cir-
cle, a concrete and practical image of the activity to be avoided is
depicted.
Indicates an important action or procedure which must be per-
formed or carried out without fail. Failure to follow the instructions
herein can lead to malfunction or damage to the pump.
Thank you for choosing the EHN type electromagnetic metering
pump.
This instruction manual consists of "Safety Section", "Outline
Section", "Installation Section", "Operation Section" and
"Maintenance Section", and deals with the correct installation,
operation, maintenance and troubleshooting procedures.
Please read through this manual carefully to ensure the optimum
performance, safety and service of your pump.
Nonobservance or misapplication of the
contents of the “Caution” section could
lead to the personal injury to users or
serious damage to the product.
Warning
Nonobservance or misapplication of the
contents of the “Warning” section could
lead to a serious accident which may
result in death.
Caution
Contents
Instruction for safety ........................................................................... 1~3
Outline of product 1. Unpacking and inspection ............................ 4
2. Principle of operation .................................. 4
3. Model identification ..................................... 5
4. Specification ................................................ 6
5. Operating function .......................................7
6. STOP function ............................................. 8
7. Over view ...................................................8·9
Installation 1. Before installation ...................................... 10
2. Precaution on handling .......................... 10·11
3. Installation ................................................. 12
4. Tubing ....................................................13·14
5. Electrical wiring ................................... 14~18
Operation 1. Operation ..............................................19~23
2. Operation of controller ..........................24~35
Maintenance Instruction for safety ...................................... 36
1. Troubleshooting...........................................36
2. Maintenance and inspection........................ 37
3. Wear parts................................................... 37
4. Dismantlement and assembly.......................38
Exploded view ..................................................................................42·43
Outline dimension ............................................................................44·45
Instruction for safety
For the Safe and
Correct Handling of the Pump
●"Safety Instruction" section deals with important details about
the handling of the product. Before the use of controller, read
through this section carefully for the prevention of personnel
injury or loss.
●Observe the instructions accompanied with "WARNING" or
"CAUTION" in this manual. These instructions are very impor-
tant to avoid dangerous situations.
●The symbols on this instruction manual have the following
meanings:

- 2 -
•Turn off power
Working on the pump with power ON may cause an elec-
trical shock. Before working on the pump, make sure to
disconnect the power cord in order to stop the pump and
other related devices.
•Terminate operation
Detecting or becoming aware of any dangerous sign or
abnormal condition, stop the operation immediately and
restart it from the beginning.
•For specified application only
The use of the pump in any application other than those
clearly specified may result in injury or damage to the
pump. Use the pump within specifications and applica-
tion range.
•No remodeling
Never try to modify the pump. Serious accidents may
result. We are not responsible for any accident or damage
due to modification without first obtaining permission or
instructions from Iwaki.
•Wear protectors
Always wear protective clothing, eye protection and
gloves before any dismantlement/assembly of the pump
or maintenance.
Electrical Shock
Prohibited
No Remodeling
Wear protective
gear
•Qualified operators only
Any operation of the pump is permitted to only the per-
son with a enough understanding of the pump.
•Specified power only
Do not apply any power other than specified one on the
nameplate. Otherwise damage or fire will may happen.
•Pay attention to dry running
Do not run pump dry for more than 30 minutes. The bolt
on the pump head may loosen and result in liquid leak-
age. Install the pump so that dry running can not occur.
Take extra care not to run the pump dry unintentionally
for more than 30 minutes for air elimination.
•Do not wet or dampen
If any electric part or wiring gets wet with the liquid
spilled over accidentally, a fire or electrical shock may
be caused. Install the system in a place free from liquid
spillage or leakage.
•Ventilate
Poisoning may result when handling toxic or odorous
liquid. Ventilate the operating site sufficiently.
•Spill-out accident
Protective measures should be taken against any acciden-
tal spill-out or leakage of the operating liquid as a result
of unexpected damage on the pump or the related piping.
Prohibited
Prohibited
Caution
Do not wet
or dampen
Caution
Instruction for safety
Warning Caution
Caution

- 3 -
•Limited operating site and storage
Do not install or store the pump in the following places:
* Flammable gas or material is used or stored.
* Ambient temperature is extremely high (40 dig.C or
higher) or extremely low (0 dig.C or lower).
•Do not place the pump close to water
The pump is not water-proof construction. If the pump
is used in a place where liquid is splashed on pump or at
humid place, electrical shock or short-circuit may happen.
•Do not damage or change power cable
Do not scratch, damage, process, or pull the power cable
forcibly. An extra load onto the cable, such as heating
the cable or placing something heavy on the cable, may
damage the cable and finally cause a fire or an electrical
shock.
•Arrange grounding
Be sure to connect grounding wire before operation.
Otherwise, an electrical shock may result. Make sure the
grounding wire is connected with the grounding terminal.
•Install an earth leakage breaker (option)
Pump operation without using an earth leakage breaker
may cause an electrical shock. Purchase an optional leak-
age breaker and install in the system.
Prohibited
•Handling of the power cable
Use of a defective or damaged power cable may result in a
fire or electrical shock. Handle the power cable carefully.
•When replacing parts
Replace the consumable parts by following the descrip-
tions in the instruction manual. Do not disassemble the
pump beyond the extent shown on the instruction manual.
•Damaged pump
Never operate a damaged pump. A damaged pump may
cause leakage or electrical shock.
•Disposal of used pump
Dispose of the used or damaged pump in accordance with
the relevant local laws and regulations. (Consult a licensed
industrial waste products disposing company.)
•Tightening torque of the pump head
Leakage may occur when the pump head fixing bolts are
loose. Make sure that the pump head is secured by tighten-
ing the 4 fixing bolts diagonally at the first operation.
Tightening torque
EHN-B11 • 21 • C21 : 2.16N•m
EHN-C31 • 36 : 2.55N•m
Caution
Prohibited
Grounding
Electrical Shock
Electrical Shock
Prohibited
Instruction for safety
Caution Caution
Caution

- 4 -
Outline of product
3) Check if the product is not damaged and any parts are not lost in
transit. Check that any bolts or nuts are not loosened.
If you find any abnormality, ask us.
2. Principle of operation
IWAKI electromagnetic metering pump the EHN series is a dia-
phragm metering pump which consists of a pump head, driving unit,
and control unit. A diaphragm is directly driven by electromagnet
force.
A reciprocating motion is made by a spring and electromagnetic
force generated by pulse current coming from a control unit. The
reciprocating motion is transferred to a diaphragm through a plunger
and makes volumetric change in a pump chamber. Pumping action is
obtained by volumetric change and by valve action in pump head.
1. Unpacking and inspection
1) Check the model code, dis-
charge capacity, discharge
pressure and voltage etc.
shown on nameplate to
confirm the pump is in your
specification.
2) Check if accessories are
attached.
a. Check valve or back pres-
sure valve : One piece
Control unit
Pump head
Driving unit
Stroke length
adjusting knob
Plunger
Diaphragm
Spring
Model Set press.
MPa Connection Wet-end material Applied pump model
CS-1S 0.2 SUS316
Hastelloy C
PTFE
EHN-B11ּ21
EHN-C21ּ31
CS-1SL
RC1/4
EHN-C360.05

- 5 -
Outline of product
3. Model identification
Pump : EHN - B 11 SH 9 R - □□
1 2 3 4 5 6 7
1. Series
EHN multi voltage type
2. Driving unit code (Average power consumption)
B : 20W C : 24W
3. Diaphragm effective diameter
11 : 10mm 21 : 20mm
31 : 30mm 36 : 35mm
4. Wet-end material
5. Connection hose diameter code
9: Rc1/4 Female screw
6. Controller function code
R: Standard type
7. Special type code
01 ~ 99 : Non standard material, Non standard connection, etc.
Control unit : EHNC - B R - □□
1 2 3 4
1. Control unit type
EHNC: Multi voltage type (with crimp contact)
2. Driving unit code
B or C
3. Controller function code
R: Standard type
4. Special type code
01 ~ 99 : Non standard specification.
Material code EPDM: Ethylene-propylene-diene-methylene PTFE: Poytetrafluro ethylene
Code Pump head Valve Valve seat Gasket Diaphragm
SH SUS316
Hastelloy C SUS316 PTFE
PTFE
+
EPDM
(Not wet-end)

- 6 -
Outline of product
4. Specification
4-1. Pump specification
Note1. Performance is obtained by pumping clean water at ambient temp in the
rated voltage.
2. Discharge capacity on the table are obtained at max. discharge pressure
(100% stroke length, 360 spm stroke rate.). When discharge pressure
is low, the pump discharges liquid much more than discharge capacity
shown as above.
3. Permissible ambient temperature : 0 ~ 40 deg. C
4. Permissible liquid temperature : 0 ~ 40 deg. C
5. Permissible voltage fluctuation: Within ±10% of the rated voltage
●Ask us for special cases such as transferring slurry liquid or so.
●Specification may be changed for product improvement without prior
notice.
Model
Disch.
capacity
ml/min
Max. disch.
press.
MPa
Stroke length
mm
(%)
Stroke
rate
spm
Average power
consumption
W
Mass
kg
EHN-B11 38 1.0 0.5~1.0
(50~100)
1~360
20 2.4
EHN-B21 100 0.4
EHN-C21 130 0.7
EHN-C31 270 0.35
EHN-C36 410 0.2
0.5~1.25
(40~100) 24 4.1
4-2. Control unit
Note 1: Max. charged voltage to the contact is 12V and 5mA current. If the con-
tact such as relay is used, its applicable load should be 5mA or below.
Note 2: The input signals over the upper limit stroke rate are stored up to 255
signals.
Note 3: The residual input signals over 360 spm are cancelled.
Note 4: Do not apply any voltage other than the specified one. It causes the
pump failure. Allowable power voltage is between AC90 - 264V.
Operation
mode
Mode Manual
EXT(Pule dividing or multiply )
EXT input
Pump operation
1 input signal : "n" pumping(s)
(Pulse multiply) Note 2
"n" input signal(s) : 1 pumping
(Pulse dividing) Note 3
When "n" is 1, the pump starts synchro-
nized operation
Input signal Potential free contact or open collector
Note 1
Display
Figures 4 digits LCD
Pump movement Green LED (one)
(Blinks synchronous with pump operation)
Power source voltage AC100V~240V, 50/60Hz Note 4
Switching Key operation
Stroke rate
Set range 1 ~ 360 spm
Set method Up or down key
Memory function By non-volatile memory
STOP input
When M - OFF Pump stops when contact signal comes.
When M - ON Pump runs when contact signal comes.
Input signal Potential free contact or open collector
Note 1
Upper limit stroke rate Stroke rate indication of manual mode
Dividing ratio/Multiply
ratio setting range
1~999
(Dividing or multiply)

- 7 -
Outline of product
5. Operating function
5-1. Manual operation
Pump operation
Operation Operation
Stop
Key operation
Use (UP) and (DOWN) keys to set a stroke rate between 1 ~
360 spm. Use (Stop/start) key to start/stop the pump. Stroke rate
can be adjusted when the pump runs or stops.
EXT input(Multiply) ×n operation (n=5)
External pulse
Pump operation 1
2 3 4 5 12 3 4 5
EXT input operation (Pulse multiply)
Pump operates with a set number of pumping between 1~999 for a
external pulse signal. The preset stroke rate in manual operation is
applied as the upper limit stroke rate in EXT operation. The pulse
signals which come while pumping for the set number of times for
a external pulse signal are stored up to 255 pulses. When the set
number of pumping is set to 1, pump operates synchronously with a
external pulse in the ratio of 1:1.
5-2. EXT operation
EXT input (Multiply) when a set number of pumping is 5
EXT input (Dividing) when a set number of pumping is 5
EXT input operation (Pulse dividing)
Pump operates with a pumping for external pulse signals. The preset
stroke rate in manual operation is applied as the upper limit stroke
rate in EXT operation. Residual input signals over 360 spm are
cancelled. When the set number of external signals is set to 1, pump
operates synchronously with a external pulse in the ratio of 1:1.
Caution
When the set number of external pulse signals for a pumping
is set to 1 in pulse dividing operation, pump operation can be
unstable due to the residual signal cancellation function but it
is not malfunction of pump. Set the number of pumping for a
external pulse signals to 1 for 1:1 operation in the pulse multiply
operation.
EXT input(Dividing) /n operation (n=5)
External pulse
Pump operation
1 2 3 4 5 1 2
3 4 5 1 2 3 4 5

STOP signal
Pump operation
Pumps does not operate
because of STOP signal.
- 8 -
Outline of product
7. O ver view
7-1. Overview of pump
6. STOP function
6-1. M – OF setting
The pump stops while STOP signal is comming(contact closed).
The pump starts running when STOP signal is stopped.
STOP signal
Pump operation
Pump operates while STOP signal comes (contact closed). The pump
operates in EXT mode while STOP signal is coming.
6-2. M – ON setting
Discharge port
Adjusting
screw
Pump head
Suction port
Base
Fix base with screws.
Stroke length
adjustment
knob
Control unit
For the pump operation,
the flow rate adjustment
and the stroke rate
adjustment·setting.
Driving unit
Pay attention
to mounting
location.
Do not have
them wet.
Nameplate
Use the pump
according to the
specification on
the nameplate.
Bleed port
Be sure to connect
a tube and return it
to the suction
side tank.

Outline of product
ON
STROKE RATE
Start/Stop key
Use this key to
start/stop the pump.
ON lamp
Lits when
power is ON
and blin ks
synchronously
with each
stroke.
Down key
Push this key to
change mode or
setting value.
Display
Operation state or
each setting value are
displayed.
Up key
Push this key to
change mode or
setting value.
7-2. Overview of controller
- 9 -
7-3. Basic display.
ON lamp lights. ON lamp blinks.
The pump is waiting in
manual operation mode.
The pump is running in
manual operation mode. The
stroke rate blinks, too.
The pump is in EXT mode.
EXT setting can be done.
The pump is running in EXT
mode.
The pump is stopped by
STOP signal..
The pump is stopped in
manual waiting mode while
STOP signal comes.
Chattering is being set.
T-10 or T-50 is displayed
other than T-5.
STOP function is set to
M-OF. M-ON is displayed
when M-ON is selected.
The multiply ratio of EXT mode
is being set. The left display
shows 5 pumpings for a pulse.
EXT input signals exceed the
pump upper limit spm in EXT
mode. Pump operates at its
upper limit spm.
Pulse multiply mode is
selected in EXT setting.
The dividing ratio of EXT mode
is being set. The left display
shows 1 pumping for 5 pulses.
Pulse dividing mode is
selected in EXT setting.
Pump is running in pulse divid-
ing/multiply operation for exter-
nal input pulses. The indication
shows spm.
( )
Key is locked. Key opera-
tions are ineffective in this
state. Release the key lock
function before operation.
ON lamp lights ON lamp blinks
Key is locked. Key opera-
tions are ineffective in this
state. Release the key lock
function before operation.

- 10 -
Installation
1. Before installation
"Strictly observe the following points."
Operators and maintenance service staff must read the instruction
manual thoroughly before installing the products. Do not operate the
pump system unless all of the contents in this manual are completely
understood.
●Dropping the pump or subjecting
it to strong impacts may result in
faulty performance. Handle the
pump with care.
●When installing the pump, avoid
places where...
• The pump is exposed to direct
sunlight or rain.
• Ambient temperature is 40 deg.
C or more.
• Relative humidity is 85% or
more.
Though the pump has a simple
waterproof and dustproof structure,
do not install it outdoor.
●Select an installation site convenient
for future maintenance and inspec-
tion, and fix the pump on a flat
floor free of vibrations.
2. Precaution on handling
Warning
●Turn off power
Working with power ON may cause an electrical shock. Before
working on the pump, make sure turn off main power.
●Terminate operation
On detecting or becoming aware of any dangerous sign or abnor-
mal condition in operation, terminate the operation immediately
and start it from the beginning again.
●Specified power only
Be sure to connect earth wire. Do not apply any power other than
specified power on nameplate.
●Keep the pump away from heat or flame
Do not place any dangerous materials or flammable objects near
the pump for the prevention of fire or accident.
●Damaged pump
Never operate any damaged pump. A damaged pump may cause
leakage or electrical shock.

- 11 -
Installation
●Ventilate.
Poisoning may result when
toxic or odorous liquid is used.
Ventilate the operating site suf-
ficiently.
●Do not wet or dampen.
If an electric part or wiring gets
wet with the liquid spilled over
accidentally, a fire or electrical
shock may be caused. Install
the system in a place free from
liquid spillage or leakage.
●Install an earth leakage
breaker (option).
Pump operation without an
earth leakage breaker may lead
to an electrical shock. Purchase
an optional leakage breaker and
install in the system.
●The control unit can be
detached, however, do not
detach it unless it is not
required. Never use the detached
control unit with other pump
models.
●Grounding.
Risk of electrical shock. Do
not operate the pump without
grounding.
●Limited operating site and
storage
Do not install or store the
pump in the following places:
• Flammable gas or material is
used or stored.
• Ambient temperature is
extremely high (40 deg.C or
higher) or extremely low (0
deg.C or lower).
• Under direct sunlight or
rainwater
• Relative humidity is 85% or
more.
●Cleaning
Do not wipe the pump body
or the nameplate with a cloth
soaked with solvent such as
benzene, thinner, or kerosene.
Coating may be removed or
colour may be changed. Use
a dry cloth or a cloth soaked
with water or neutral deter-
gent.
Prohibited
Caution
Prohibited
Benzine
Thinner

- 12 -
Installation
3. Installation
Caution
Detecting or becoming aware of a dangerous sign or abnor-
mal condition in operation, stop the operation and take the
procedure from the top.
●Installation
Install the pump at a site where
ambient temperature does not
exceed 40 deg.C and relative
humidity does not exceed 85%.
(There should be no dew con-
densation in the control unit.)
The site must be selected keep-
ing in mind ease and efficiency
for maintenance and inspection
work.
Do not expose the pump to
sunlight or rainwater. Cover the
pump when placing it outside.
●Place the pump as close to the
suction tank as possible.
●If the pump is used to feed any
liquid that generates air bub-
bles easily (Hydrazine solution,
etc.), it must be positioned in
a cool, dark place away from
direct sunlight.
When using a tank, realize a
flooded suction system.
●Anchoring pump
Select a flat floor free of liquid
splash for installation of the
pump. Use M5 bolts to firmly
anchor the pump so as not to
allow any vibration.
Caution

- 13 -
Installation
4. Tubing
1) Tape the air bleeding union
(Attached to the pump) and screw it
in the pump head.
2) Have the piping short and less
bends as much as possible to reduce
flow resistance.
3) The fitting bore is Rc1/4 female
thread. Be sure to connect each
connection on both suction/dis-
charge piping to eliminate liquid/
air leakage.
4) Piping for air elimination.
Be sure to return the end of hose to
a tank or container after connect-
ing a hose to the bleed port.
Caution
Regarding the SH type, discharge
pressure can not be fully opened
by the adjusting screw. Install a
discharge valve on discharge pipe
for opening pressure.
Fig.C
5m
Suction side tank
Discharge side tank
Bleed port
5) Mounting check valve
A check valve is packed to
avoid over feeding. Be sure to
install the check valve in fol-
lowing condition.
a. Suction side liquid level is
higher than discharge side
liquid level. (See Fig. A)
Injection point is below
suction side liquid level at
atmospheric pressure.
b. Suction side pressure is
higher than that of injection
point. (See Fig. B.)
c. Difference of liquid level in
height is 5 meters or less,
even if discharge side liquid
level is higher than suction
side. (See Fig. C.)
Caution
Periodically wash or replace
the check valve with new one
because it may be clogged by
crystal.
Check valve
OUT
IN
Suction side tank
Fig.A Discharge side tank
Fig.B
Discharge
Suction
Return the end
tube to a tank.
Adjusting screw

Electrical works must be done by a qualified person. We are
not responsible for any injury and damage by any person
other than a qualified person,
- 14 -
Installation
d. Discharge pressure (Pipe
resistance, discharge head or
so) is below 0.13MPa. (Load
pressure is 0.049MPa for C36).
• The check valve should be
installed at discharge tube end at
least 1 meter away from pump.
5. Electrical wiring
5-1. Wiring of power source
1) Confirm that main power source is turned off before wiring.
2) Wiring must be done according to your electrical works standard
using good wiring equipment/device.
Caution
Power voltage should be charged at a sitting via switch or
relay. Otherwise malfunction of CPU may happen.
Power
When power is charged at a setting When power is charged gradually
ON
OFF
Power
ON
OFF
For selecting a relay, refer to P16 which mentions the precaution
when pump is controlled by relay ON/OFF.
Caution

Make sure wires are connected
securely via crimp contacts at the
end of the power cord.
Caution
Never put other voltage than rated
voltage. Otherwise electronic circuit
may be broken.
3) Be sure to connect ground wire.
4) Do not share a plug socket with a
high power equipment which may
generate surge voltage. Otherwise
electronic circuit may be failed.
Pay attention to noise generated
by inverter or so.
- 15 -
Installation
●Precaution when pump power is turned ON/OFF by relay.
Caution
The control unit is equipped with CPU. It is recommended to
stop the pump through STOP input terminal. Avoid turning ON/
OFF power source because it may cause malfunction of CPU.
If there is no choice but turning ON/OFF power, pay attention
to following points.
In case power is turned ON/OFF by the relay, its contact vol-
ume must be 5A or more. Contact point may be welded if con-
tact volume is 5A or below.
P
Surge absorption
element
P
Noise cut transformer
a. Install a surge absorption element
(Varister or so of 2000A or more
durability) at pump power connec-
tion part.
b. Install noise cut transformer.
5) The control unit can be removed
easily from the pump driving
unit. Do not mount the control
unit to a different pump model.
Electronic circuit or driving unit
may be damaged.
●Surge voltage
Caution
Electronic circuit of the control unit may be failed by extremely
large surge voltage. Do not place the pump near to the high
power equipment of 200V or more which may generate large
surge voltage. If use of high power equipment is inevitable,
take any of the following measures.
㨪

- 16 -
Installation
5-2. Wiring of external input signal
Caution
Risk of electrical shock. Never connect wires while power is
turned on. Controller may be short-circuited. Turn off power
before wiring work.
Caution
Wait for one minute after the power is turned off, because elec-
tricity is still charged in the pump right after turning off power.
External signal
EXT function : Stroke rate is controlled by pulse signal.
STOP function : ON/OFF operation by external signal.
Use either a potential free contact or a open collector for exter-
nal signal. When a pulse signal is used, pulse width should
be between 10ms and 100ms and pulse speed should be 360
pulses/minute or below.
Caution
●Wiring of EXT and STOP
Do not install the power cord and the EXT and STOP wires in
parallel. Do not bind or combine the power cord with the EXT
and STOP wires by a concentric cable (5 wires cable or so).
Otherwise noise is generated from the EXT and STOP wires
due to induction effect from the power cable and results in
wrong operation or failure.
●When using SSR (solid state relay) for EXT/STOP signal
input
When using SSR for EXT/STOP signal input, use the recom-
mended products stated below. Any SSR other than recom-
mended can cause malfunction.
1. G3FD-102 S or G3FD-102SN made by OMRON
2. G3TA-IDZR02S or G3TA-IDZR02SM
Refer to information materials such as catalogue of manufac-
turer for further information.
●When using a type device for EXT/STOP signal input
When using a type device such as relay for EXT/STOP signal
input, select some device of which the minimum application
load is 5mA or below.
If the relay of contact point volume 5A is used for EHN, it can
be used for max. 150 thousands times of ON/OFF operation.
If 150 thousands times or more of ON/OFF operation are
required, or a power source is shared with a large capacity
equipment, the contact may be welded by surge voltage. In
this case use the relay of contact volume of 10A or more. If its
durability is not enough, use non contact transistor relay (ex.
G3F made by OMRON or so). For details refer to catalogue or
other documents of equipment manufacturer.

- 17 -
Installation
●Wiring procedure
Caution
Used cord must be 7.8 mm of outer diameter. If other diameter is
used, perfect connection and sealing can not be obtained, mal-
function of an electronic circuit may result.
1) Remove gasket on the top of control unit and then remove screw
, gasket and two screws above stroke length adjusting
knob and remove the control unit.
2) Remove four screws on the bottom of control unit and remove
controller cover.
3) Remove cord nut for signal cord and remove protective cap .
The cap is not used when cord is connected. Pull cord gasket
out of controller unit.
4) Insert an external signal cord through cord nut and cord gasket
into the control unit.

- 18 -
Installation
6) Mount control cover and mount the controller in the reverse proce-
dure of above items 1) and 2).
Tightening torque of each screw is as follows:
Screw : 0.39N.m
Screw : 0.39N.m
Screw : 0.8N.m
Caution
Do not forget to mount gaskets and . Without them, liquid
may get into controller and controller may be failed.
Wiring to socket for signal input
Terminal for
power source
Plug
H
Socket
Potential free contact signal Open collector signal
Socket
STOP signal STOP signal
EXT signal
EXT signal
456 456
5) Remove plug from socket . Connect a signal cord to the
plug with screw driver and mount it on the socket . Pull the
signal cord from the outside of the control unit to adjust the slack
and then mount the cord nut securely by hand. (The cord is
sealed by cord gasket .)

●Do not operate the pump with a completely closed dis-
charge-side valve.
Operating the pump with the discharge-side valve fully closed
may lead to liquid leakage or pipe rupture. Make sure not to
operate the pump with the discharge-side valve closed.
●Do not run pump dry.
A pump which has been run dry may experience liquid leak-
age during its liquid feeding operation. Make it a rule to run the
pump after supplying liquid inside the pump.
Overheat, deformation of the pump unit (pump head, valve case,
etc.), or looseness of the pump head can happen by a long period
(longer than 30 minutes) of dry running. This may result in liq-
uid leakage.
●Re-tighten bolts of pump head
Loosened bolts on pump head may cause liquid leakage. To avoid
liquid leakage caused by loosened bolts, periodically tighten four
hex. socket head bolts in diagonal order. Also at the time of initial
operation, tighten four bolts diagonally because the bolts may be
loosened during storage or transportation.
Tightening torque
- 19 -
Operation
1. Operation
After the installation, piping, and wiring processes are completed,
operate the pump in accordance with the following steps.
Model
Caution
Torque Remarks
EHN-B11 • 21 2.16N•m M4 hex. socket head bolts
EHN-C21 2.16N•m M4 hex. socket head bolts
EHN-C31 2.55N•m M4 hex. socket head bolts
EHN-C36 2.55N•m M5 hex. socket head bolts
1-1. Bleeding
Bleeding is a process undertaken to eliminate air inside the suction-
side tube and the pump head. Make sure to carry out bleeding prior
to the initial operation of the pump and/or after replacing the liquid
in the tank. For safe bleeding, first set a pipe to the air-vent port of
the air vent unit.
Caution
Do not rotate the adjusting screw beyond the OPEN-SHUT
name plate.
Caution
Some liquids used in the pump may cause skin trouble or affect
the quality of mechanical parts. Wipe off the liquid immediately
when it wets the hand or mechanical parts.
Warning
Both air and chemical go out together from the end of bleeding
tube. Return the bleeding tube to a chemical tank or another
vessel.
Caution
The pump may run and discharge chemical for one shot as
power is turned on, however, it is not malfunction.