Emerson EXN Manual De Instrucciones

G e n e r a l i n f o r m a t i o n :
EXN are unipolar stepper motor driven electronic expansion
valves for precise control of refrigerant mass flow in
refrigeration systems.
The valve is not released for refrigeration applications such
as cold room and refrigeration display cabinet.
The valve consists of two individual part:
-
Valve body & Coil
WARNING
• The device has a potential ignition source and has not
been qualified according to ATEX standards. Installation
only in "non-explosive location".
• Do not approach strong magnetic object to the valve
casing.
• Do not use the valve in case the valve suffers a hard
impact.
S a f e t y i n s t r u c t i o n s :
• Read operating instructions thoroughly. Failure to
comply can result in device failure, system damage or
personal injury.
• This product is intended for use by qualified personnel
having the appropriate knowledge and skills like trained
according to EN 13313 or a specific training for
flammable refrigerants.
• Flammable refrigerants require special handling and
care due to its flammability. Sufficient ventilation is
required during service of the system.
• Contact with rapidly expanding gases can cause
frostbite and eye damage. Proper protective equipment
(gloves, eye protection, etc.) has to be used.
• Ensure that the system is correctly labelled with applied
refrigerant type and a warning for explosion risk.
• In a severely contaminated system, avoid breathing acid
vapours and avoid contact with skin from contaminated
refrigerant / lubricants. Failure to do so could result in
injury.
• Before opening any system make sure pressure in
system is brought to and remains at atmospheric
pressure.
• Do not release any refrigerant into the atmosphere!
• Do not exceed the specified maximum ratings for
pressure, temperature, voltage and current.
• Ensure that the system piping is grounded.
• Do not connect valve directly to supply voltage. Use a
suitable stepper motor driver.
• Before installation or service disconnect all voltages
from system and device.
• Observe and avoid mechanical damage of component
housing.
• Do not use any other fluid media without prior approval
of EMERSON. Use of fluids not listed could result in:
- Change of hazard category
consequently change of conformity assessment
requirement for product in accordance with European
Pressure Equipment Directive 2014/68/EU.
• Ensure that design, installation and operation comply
with European and national standards/regulations.
• Do not operate system before all cable connections are
completed.
• For flammable refrigerants only use valves and
accessories approved for it!
Emerson Climate Technologies GmbH
Pascalstrasse 65 I 52076 Aachen I Germany
O P E R A T I N G I N ST RU C T I O N S
Electronic Expansion Valves EXN
M o u n t i n g l o c a t i o n : ( F i g . 1 / F i g . 4 )
• The valve must be installed with head upside or within
± 90° from upside as per Fig. 1.
• For best results locate the valve as close as possible to
the distributor or inlet of evaporator.
• Allow 35 mm space above the valve to mount the coil as
shown in Fig.4.
: The valve must be installed in an appropriate
housing to protect them from mechanical damage or shock.
I n s t a l l a t i o n :
• The valve has Bi-flow performance capability.
• Protect the orifice of valve against entering particle by
means of installing filter or filter drier at the inlet of valve
or on liquid line.
• Install an EMERSON sight glass AMI or MIA before the
valve.
• Make sure that the valve is fully open during brazing/
pressure test / leakage Test.
B r a z i n g : ( F i g . 2 )
• Perform the brazing joint as per EN 14324.
• Before and after brazing clean tubing and brazing joints.
• Minimize vibrations in the piping lines by appropriate
solutions.
• To avoid oxidization, it is advised to purge the system with
an inert gas such as nitrogen while brazing.
• Do not exceed the max. surface temperature of 120 °C!
• Remove the coil by pulling it from valve prior to brazing.
P r e s s u r e T e s t :
After completion of installation, a pressure test must be
carried out as follows:
- according to EN 378 for systems which must comply with
European pressure equipment directive 2014/68/EU.
- to maximum working pressure of system for other
applications.
T i g h t n e s s T e s t :
Conduct a tightness test according to EN 378-2 with
appropriate equipment and method to identify leakages
from joints and products. The allowable leakage rate must
be according system manufacturer's specification.
Warning:
• Failure to pressure test or tightness test as described
could result in loss of refrigerant, damage to property
and/or personal injury.
• The tests must be conducted by skilled personnel
with due respect regarding the danger related to
pressure.
E l e c t r i c a l c o n n e c t i o n :
• Entire electrical connections have to comply with
local regulations.
of product and
• Improper wiring will result wrong direction of rotation
or no rotation of stepper motor.
• Ensure that the cables are mounted without tension;
always leave the cable a bit loose.
• Ensure that cables are not mounted near sharp edges.
• Do not bend or mechanically stress the cable outlet,
maintain a clearance of 20 mm to neighbouring parts.
• The connecting part of the lead wire must be securely
fixed so as not to be disconnected by vibration.
www.climate.emerson.com/en-gb
Wiring and mounting of coil: (see Fig. 4a-c)
•
Prewired coil with cable length of approximately 1 meter
is ready for connection to the electronic board.
•
Push coil on the valve and rotate until the four recesses
at coil brackets rests (click) on the four stoppers at the
valve head.
Wiring to driver/controller: (Fig. 3)
•
See the wiring diagram of applied driver/controller.
WH = white
YE = yellow
RE = red (common)
O p e r a t i o n :
• All valves are delivered at full open. Do not charge
system before closuring the valve.
• Check for leaks, sufficient refrigerant charge and be sure
no flash gas is present before attempting to check valve
operation.
• See operating instructions
driver/controller.
• If the power to the valve is interrupted, the valve will keep
as the position it was before power off.
S e r v i c e / M a i n t e n a n c e :
• Before shutting the power off, bring the valve to fully close
position.
• Defective EXN must be replaced, they cannot be
repaired.
• Before any debrazing ensure that the flammable
refrigerant is pumped out of the system and the room
around the system is well vented so no refrigerant left.
• According to EN 378-4
maintenance, tightness tests shall be carried out at the
relevant part of the refrigerating system. This shall apply
where appropriate following any repair.
• For motor check, use an ohmmeter with suitable range.
• Internal resistance between each winding is 150 Ω ±10%
(windings W1-4, see Fig. 3).
• NOTE: Zero pulse (base point) shall be the point of full
close position of valve. The rotor movement is limited up
to 3500 pulses (half steps) but the valve shall not be
operated beyond 2200 pulses (No warranty).
T e c h n i c a l D a t a :
Max. allowable pressure PS
Temperature range TS
Storage / Transport / Ambient
Medium
Nominal Supply Voltage U
Resistance per phased
Connection (DN)
Solenoid coil
Fluid group (PED)
Released Refrigerants
Fluid Group II* R134a, R410A,
Fluid Group I* R32, R454B,
Fluid Group I* R290
NOTE: *) according to PED 2014/68/EU.
Marking
Dimensions
OI_EXN_A1_A2L_A3_EN_DE_FR_ES_IT_RU_Rev03_865920.docx
EN
OR = orange
BL = blue
of used electronic
during each periodic
45 bar
-30...+60 °C
-30...+70 °C
12 VDC ±10 %
150 Ω ±10 %
1/2" ODF
EXN-125
I + II
R407C,
R1234ze (A2L)
R452B, R454C,
R1234yf
not required
See Fig. 5
Date: 27.04.2022