dixell XEV11D Operating Instructions Manual

dIXEL
XEV11D
ON-OFF ELECTRONIC EXPANSION VALVE DRIVERS
CONTENTS
1.

General warning _____________________________________________________ 1

2.

General description ___________________________________________________ 1

3. Regulation __________________________________________________________ 1
4.

Front panel _________________________________________________________ 1

5. User Interface _______________________________________________________ 2
6. Parameters List ______________________________________________________ 2
7. Digital Inputs ________________________________________________________ 3
8. Plant Starting Function _________________________________________________ 3
9. Electrical Connections _________________________________________________ 3
10. RS485 serial line _____________________________________________________ 3
11. How to use the HOT KEY ______________________________________________ 3
12. Display messages ____________________________________________________ 3
13. Technical data _______________________________________________________ 3
14. Wiring connections ___________________________________________________ 3
15. Standard values _____________________________________________________ 3
16. Example of application ________________________________________________ 4
1. GENERAL WARNING
1.1 PLEASE READ BEFORE USING THIS MANUAL
•
This manual is part of the product and should be kept near the instrument for easy and quick
reference.
•
The instrument shall not be used for purposes different from those described hereunder. It
cannot be used as a safety device.
•
Check the application limits before proceeding.
SAFETY PRECAUTIONS
1.2
• Check the supply voltage is correct before connecting the instrument.
•
Do not expose to water or moisture: use the controller only within the operating limits avoiding
sudden temperature changes with high atmospheric humidity to prevent
condensation
• Warning: disconnect all electrical connections before any kind of maintenance.
•
Fit the probe where it is not accessible by the End User. The instrument must not be opened.
•
In case of failure or faulty operation send the instrument back to the distributor or to "Dixell
S.p.A." (see address) with a detailed description of the fault.
•
Consider the maximum current which can be applied to each relay (see Technical Data).
•
Ensure that the wires for probes, loads and the power supply are separated and far enough from
each other, without crossing or intertwining.
•
In case of applications in industrial environments, the use of mains filters (our mod. FT1) in
parallel with inductive loads could be useful.
2. GENERAL DESCRIPTION
The XEV11D module is able to drive ON/OFF electronic expansion valves. This module permits to
regulate the superheat (SH) of the fluid that runs into refrigerating unit in order to obtain optimized
performance and a climatic or load conditions independent functioning. XEV11D modules are
equipped with two probe inputs, one for 4÷20mA or 0÷5V pressure transducer and another for Pt1000
or NTC temperature probe. A LAN connection permits to transmit the pressure signal to all other XEV
modules in order to use only one pressure transducer in multiplexed cabinet applications. There are
also two configurable digital inputs, one of them must be configured to get cooling request. The other
digital input can be used to signal to the instrument that defrost is in progress. To complete instrument
equipment, a RS485 serial link permits to connect XEV11D to dIXEL monitoring and supervising
systems.
XEV11D can be programmed with KB1-PRG remote keyboard or with Dixell HOT-KEY.
3. REGULATION
The superheat regulation is performed only when the cooling request is active. The following scheme
shows how device reads the request of cooling:
The regulation is obtained with PI controller that it changes the valve opening percentage. Opening
percentage is obtained from average of Opening Time respect to CyP time period like following
diagram:
1592019010 XEV11D GB r1.2 2008.07.08.doc
Operating instruction manual
With opening percentage we mean percentage of cycle period where valve is open. For example, if
CyP=6s and we say: "The valve opening percentage is 50%"; we mean the valve is opened for 3s
during cycle period.
3.1 INJECTION SIGNALLING
The graph illustrates how to work the function for injection problems signalling. When superheat stays
in dSH (delta SuperHeat) band and valve increases continuously its opening more than dOP (delta
OPening) for ind time (injection delay) the driver signals a gas problem. When this event occurs, the
behaviour of the valve can be fitted to your demand. Trough inb (injection behaviour) parameter you
can choose if the valve have to close completely (inb=cL) , or if regulation have to continue normally
with PI.
formation of
4. FRONT PANEL
KEYS COMBINATIONS
4.1 XEV11D LEDS
XEV11D has four LEDs. Their meaning is described in the following table:
LED
POWER
TX/RX
TX/RX
VALVE
XEV11D
XEV11D
To display and to modify the set
point. In programming mode it
selects a parameter or it
confirms a value.
In programming mode it slides
the codes of the parameters or it
increases their values.
In programming mode it slides
the codes of parameters or it
decreases their values.
+
To lock or to unlock the keyboard.
+
To enter to programming mode.
Press and hold this keys combination about 5 seconds to activate
+
valve ON function (described in Plant start section). If you are in
programming mode this combination permits to leave it.
MODE
ON The power supply is ok
OFF There is no RS485 activity
BLINKING Serial communication present
ON Valve is opened
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KB1-PRG
Function
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