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EVD mini
Superheat control for unipolar electronic expansion valve
User manual
H i g h E f f i c i e n c y S o l u t i o n s
NO POWER
& SIGNAL
CABLES
TOGETHER
READ CAREFULLY IN THE TEXT!
ENG
WARNINGS DISPOSAL
CAREL bases the development of its products on decades of experience in HVAC, on the continuous investments in technological innovations to products, procedures and strict quality processes with in-circuit and functional testing on 100% of its products, and on the most innovative production technology available on the market. CAREL and its subsidiaries nonetheless cannot guarantee that all the aspects of the product and the software included with the product respond to the requirements of the final application, despite the product being developed according to start-of-theart techniques. The customer (manufacturer, developer or installer of the final equipment) accepts all liability and risk relating to the configuration of the product in order to reach the expected results in relation to the specific final installation and/or equipment. CAREL may, based on specific agreements, acts as a consultant for the positive commissioning of the final unit/application, however in no case does it accept liability for the correct operation of the final equipment/system.
The CAREL product is a state-of-the-art product, whose operation is specified in the technical documentation supplied with the product or can be downloaded, even prior to purchase, from the website www.carel.com.
Each CAREL product, in relation to its advanced level of technology, requires setup/configuration/programming/commissioning to be able to operate in the best possible way for the specific application. The failure to complete such operations, which are required/indicated in the user manual, may cause the final product to malfunction; CAREL accepts no liability in such cases.
Only qualified personnel may install or carry out technical service on the product.
The customer must only use the product in the manner described in the documentation relating to the product.
In addition to observing any further warnings described in this manual, the following warnings must be heeded for all CAREL products:
• prevent the electronic circuits from getting wet. Rain, humidity and all types of liquids or condensate contain corrosive minerals that may damage the electronic circuits. In any case, the product should be used or stored in environments that comply with the temperature and humidity limits specified in the manual;
• do not install the device in particularly hot environments. Too high temperatures may reduce the life of electronic devices, damage them and deform or melt the plastic parts. In any case, the product should be used or stored in environments that comply with the temperature and humidity limits specified in the manual;
• do not attempt to open the device in any way other than described in the manual;
• do not drop, hit or shake the device, as the internal circuits and mechanisms may be irreparably damaged;
• do not use corrosive chemicals, solvents or aggressive detergents to clean the device;
• do not use the product for applications other than those specified in the technical manual.
All of the above suggestions likewise apply to the controllers, serial boards, programming keys or any other accessory in the CAREL product portfolio.
CAREL adopts a policy of continual development. Consequently, CAREL reserves the right to make changes and improvements to any product described in this document without prior warning.
The technical specifications shown in the manual may be changed without prior warning.
The liability of CAREL in relation to its products is specified in the CAREL general contract conditions, available on the website www.carel.com and/or by specific agreements with customers; specifically, to the extent where allowed by applicable legislation, in no case will CAREL, its employees or subsidiaries be liable for any lost earnings or sales, losses of data and information, costs of replacement goods or services, damage to things or people, downtime or any direct, indirect, incidental, actual, punitive, exemplary, special or consequential damage of any kind whatsoever, whether contractual, extra-contractual or due to negligence, or any other liabilities deriving from the installation, use or impossibility to use the product, even if CAREL or its subsidiaries are warned of the possibility of such damage.
INFORMATION FOR USERS ON THE CORRECT
HANDLING OF WASTE ELECTRICAL AND ELEC-
TRONIC EQUIPMENT (WEEE)
In reference to European Union directive 2002/96/EC issued on 27 January
2003 and the related national legislation, please note that:
1. WEEE cannot be disposed of as municipal waste and such waste must be collected and disposed of separately;
2. the public or private waste collection systems defined by local legislation must be used. In addition, the equipment can be returned to the distributor at the end of its working life when buying new equipment;
3. the equipment may contain hazardous substances: the improper use or incorrect disposal of such may have negative effects on human health and on the environment;
4. the symbol (crossed-out wheeled bin) shown on the product or on the packaging and on the instruction sheet indicates that the equipment has been introduced onto the market after 13 August 2005 and that it must be disposed of separately;
5. in the event of illegal disposal of electrical and electronic waste, the penalties are specified by local waste disposal legislation.
W arranty on the materials: 2 years (from the date of production, excluding consumables).
A pproval: the quality and safety of CAREL INDUSTRIES products are guaranteed by the ISO 9001 certified design and production system, as well as by the marks (*).
CAUTION: separate as much as possible the probe and digital input signal cables from the cables carrying inductive loads and power cables to avoid possible electromagnetic disturbance.
Never run power cables (including the electrical panel wiring) and signal cables in the same conduits.
NO POWER
& SIGNAL
CABLES
TOGETHER
READ CAREFULLY IN THE TEXT!
3 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
Content
1. INTRODUCTION 7
1.2 Functions and main characteristics ............................................................. 7
2. INSTALLATION 8
2.1 Dimensions and mounting-mm (in) .......................................................... 8
2.2 Description of the terminals ......................................................................... 9
2.3 Wiring diagram for superheat control ...................................................... 10
2.5 Copy parameters with programming key ................................................ 11
3. USER INTERFACE 12
3.1 Keypad............................................................................................................. 12
3.4 Restore factory parameters (default) ........................................................ 12
4. COMMISSIONING 13
5. FUNCTIONS 15
5.2 Analogue positioner (0-10 Vdc) ................................................................. 16
5.3 Superheat control with 2 temp. probes ................................................... 16
5.5 Regolazione speciale: smooth lines ...........................................................17
5.6 Control parameters for protection functions .......................................... 18
6. PROTECTORS 19
21
8. NETWORK CONNECTION 23
8.1 RS485 serial configuration ..........................................................................23
8.2 Network connection for commissioning via PC .....................................23
8.3 Visual parameter manager ..........................................................................23
8.4 Restore default parameters .........................................................................24
8.5 Setup by direct copy .....................................................................................24
8.6 Setup using configuration file ....................................................................25
8.7 Read the configuration file on the controller ..........................................25
8.8 Variables accessible via serial connection ...............................................26
8.10 Special control states ....................................................................................28
9. ALARMS 30
9.1 Types of alarms ..............................................................................................30
9.4 Valve emergency closing procedure .........................................................30
10. TROUBLESHOOTING
11. TECHNICAL SPECIFICATIONS
32
34
5 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
1. INTRODUCTION
EVD mini is a range of drivers designed for the control of CAREL singlepole electronic expansion valves used in refrigerant circuits. EVD mini controls refrigerant superheat and optimises refrigerant circuit performance; it guarantees significant system flexibility being compatible with various types of refrigerants, in applications with refrigerators and chiller/air-conditioners. It features low superheat protection (LowSH), high evaporation pressure (MOP) and low evaporation pressure (LOP) functions.
As regards network connectivity, the driver can be connected via serial
RS485/ Modbus® to:
• a pCO programmable controller
• a CAREL supervisor.
Another possibility involves operation as a simple positioner with 0 to 10
Vdc analogue input signal, or as a manual positioner via RS485. EVD mini can be supplied with LED display for information on the instant superheat value and any active alarms, or for performing the commissioning operations. The latter involves setting just three parameters: refrigerant, operating mode (showcase, air conditioner, etc.) and superheat set point.
The driver can also be setup using a computer via the serial port. In this case, the VPM program (Visual Parameter Manager) needs to be installed, downloadable from http://ksa.carel.com, and the USB-RS485 converter connected.
The ratiometric pressure probe specified as default for assembly is P/N
SPKT0013P0, with an operating range from -1 to 9.3 barg. Alternatively, other probes can be installed, setting the corresponding parameter accordingly. See the “Functions” chapter..
P/N Type
SPKT0053P0 -1…4.2 barg
SPKT0013P0 -1…9.3 barg
SPKT0043P0 0…17.3 barg
SPKT0033P0 0…34.5 barg
P/N Type
SPKT00B6P0 0…45 barg
SPKT00E3P0 -1…12.8 barg
SPKT00F3P0 0…20.7 barg
Tab. 1.b
Single-pole valve (P/N E2V**F**C1/ E3V**B**C1)
Fig. 1.b
Ultracap module (P/N EVDMU**N**)
The module guarantees temporary power to the driver in the event of power failures, for enough time to immediately close the connected electronic valve. It avoids the need to install a solenoid valve. The module is made using Ultracap storage capacitors, which ensure reliability in terms of much longer component life than a module made with lead batteries.
1.1 Models
P/N Description
EVDM001N00 EVD mini 24 V with display
EVDM000N00 EVD mini 24 V without display
EVDM010N00 EVD mini 115/230 V without display
EVDM011N00 EVD mini 115/230 V with display
Tab. 1.a
Fig. 1.c
Ferrite (P/N 0907879AXX)
Clamp-on ferrite for use in certain applications. See the technical specifications table.
1.2 Functions and main characteristics
In summary:
• superheat control with LowSH, MOP, LOP functions;
• compatibility with various types of refrigerants;
• guided setup procedures first, entering just three parameters on the user interface: refrigerant (Gas), type of control (Mode) and superheat set point (Superheat);
• activation/deactivation of control via digital input or remote control via serial connection;
• controller and valve power supply incorporated (230 V/115 V);
• RS485 serial communication incorporated (Modbus protocol);
• IP65;
• operating conditions: -25T60C° (-13T140°F);
• compatible with Carel E2V and E3V single-pole valves.
From software revision 1.6 and higher, new functions have been introduced:
• hot gas bypass by pressure;
• hot gas bypass by temperature.
The smooth lines function has been introduced starting from software revision 1.8.
Fig. 1.d
Programming key with power supply (P/N IROPZKEYA0)
The key can be used to quickly program the controllers, reducing the risk of errors. This accessory also allows fast and effective technical service, and can be used for programming the controllers in just a few seconds, also during the testing phase.
1.3 Accessories
Pressure probe cable (see technical leaflet +050000484), pressure probe (-1…9.3 barg, P/N SPKT0013P0) and temperature probe (P/N
NTC006HP0R).
Fig. 1.e
USB/RS485 converter (P/N CVSTDUMOR0)
The converter ensures connection between the computer used for configuration and the EVD mini driver.
Fig. 1.a
7
Fig. 1.f
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
2. INSTALLATION
2.1 Dimensions and mounting-mm (in)
EVD mini (24 V)
EVD mini (230 V)
Mounting on DIN rail:
YES
YES with screws
YES
NO
O
n
D
I
N
rail mounting:
1. Fasten the DIN rail and fit the controller from point
A
;
2. 24V model: use a screwdriver to remove the two side slots before installing any other controllers alongside.
EV D mini (24 V)
2
1
EV D mini (24 V)
98
(3.9)
87
(3.4)
72
(2.8)
GAS Type
Mode
Super Heat
BASSO/ BOTTOM
60 (2.4)
74,1 (2.9)
88 (3.5)
Fig. 2.a
EV D mini (230 V)
33 (1.3)
GAS Type
Mode
Super Heat
2
Fig. 2.c
A
EV D mini (230 V)
GAS Type
Mode
Super Heat
GAS Type
Mode
Super Heat
70,7 (2.78)
Fig. 2.b
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
BASSO/ BOTTOM
A
Fig. 2.d
S
crew mounting
On the wall, mark the positions of the holes as per the figure and drill the holes (Ø < 4mm). Then tighten the fastening screws.
42,7 (1.68)
GAS Type
Mode
Super Heat Ø 4 (0.2)
74,10 (2.9)
Fig. 2.e
8
ENG
2.2 Description of the terminals
EV D mini 24 V
CAREL E2 V/ E3V
unipolar valve
0,3 Nm
A B C D
UL T R A C A P
Module ratiometric pressue transducer
3
E
1
Ferrite/ Ferrite bead cod. 0907879AXX
F
S 2 S 1 S 2 S 1
S2 S1
GAS Type
Mode
Super Heat
CAREL E2 V/ E3V
unipolar valve
0,3 Nm
A
EV D mini (230 V)
B C D
UL T R A C A P
Module ratiometric pressue transducer
3
E
1
Ferrite/ Ferrite bead cod. 0907879AXX
F
S 2 S 1 S 2 S 1
1
S 2 S1
GAS Type
Mode
Super Heat
1
PC
VPM
2
CVSTDUM0R0
Modbus®
RS485 pCO shield
G shield
H2
H1
24 Vac digital input to start the regulation
24 Vdc
20 VA
230 Vac
Fig. 2.f
Key:
Ref.
A
Terminal Description
ExV Single-pole valve connection
+13 V (in)
B +13 V (out) Ultracap module connection (accessory)
GND
Signal
C
Ground
D
E
F
H1
(24 Vac power supply)
DI
-
G
G0
GND
5Vref
Signal
-
S2 probe (temperature)
Earth for S2 probe
Earth for S1 probe
Power S1 active probe
S1 probe: pressure or temperature
Connection as positioner (0 to 10 V input)
Connection for superheat control with 2 temperature probes
Power supply, 24 V ac
Power supply, 0 V ac
Digital input to enable control
1
PC
VPM
2
CVSTDUM0R0
Modbus®
RS485 pCO shield
G shield
Fig. 2.a
Ref.
H2
(24 Vdc power supply)
H3
(230 V power supply)
G
1
2
DI
L
N
Terminal Description
G Power supply, 24 Vdc
G0 Power supply, 0 Vdc
Digital input to enable control
230 V power supply, line
230 V power supply, neutral
DI 230 V digital input to enable control
GND
Tx/ Rx +
Tx/ Rx -
Terminal for RS485 connection
PC for configuration
USB – RS485 Converter
H3
Tab. 2.a
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ENG
2.3 Wiring diagram for superheat control
• EVD mini requires the use of an evaporation pressure probe S1 and suction temperature probe S2, which will be fitted downstream of the evaporator, and a digital input to enable control. Alternatively, the signal to enable control can be sent via a remote RS485 connection;
• input S1 is programmable and connection to the terminals depends on the parameter settings. See the chapters “Commissioning” and
“Functions”.
Note: for details on installing probes, see the “EEV system guide”
(+030220810).
CAREL E2 V/ E3V
unipolar valve
0,3 Nm
2 1
S2 S1
2.4 Installation
For installation, proceed as shown below, with reference to the wiring diagrams and the technical specifications table:
1. connect the probes: these can be installed up to a maximum distance of 10 m from the driver; select the pressure probe suitable for the refrigerant. For details on the recommended pressure probe for each refrigerant, see “Commissioning”;
2. connect any digital inputs, maximum length 10 m;
3. connect the valve cable: it is recommended to use a maximum cable length of 1 m for E2V and E3V valves.
4. the 24 V models can be powered at:
• 24 Vac: use a class II safety transformer, adequately protected against short-circuits and overload. Transformer power must be between
20 and 50 VA, as shown in the technical specifications table;
• 24 Vdc: use an external power supply, the see technical specifications table;
5. the connection cables must have a minimum cross-section of 0.35 mm 2 ;
6. power on the driver: the LED on the power supply/display comes on and the driver will be immediately operational, with the default parameters: a. Refrigerant = R404A; b. Type of control: multiplexed showcase/cold room; c. Superheat set point = 11 K.
7. program the driver, if necessary: see the “User interface” chapter;
8. connect to the serial network where required. See the following diagrams for connecting the earth on the 24 V EVD mini models.
EV
D
mini 24 Vac in serial network
Case 1: multiple drivers connected in a network, inside the same electrical panel, powered by the same transformer
GAS Type
Mode
Super Heat
PC pCO
24 Vac 230 Vac
Fig. 2.h
Case 2: multiple drivers connected in a network, inside different electrical panels with the same earth point
4
PC
VPM
5
CVSTDUM0R0
3
24 Vdc
230 Vac
20 VA
24 Vac
Fig. 2.g
Key:
1
2
3
4
5
Ratiometric pressure transducer – evaporation pressure
NTC – suction temperature
Digital input to enable control
Personal computer for configuration
USB / tLAN converter
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
10
PC pCO
24 Vac
20 VA
Fig. 2.i
230 Vac 24 Vac
20 VA
230 Vac
Important: Earthing of G0 and G in driver EVD mini 24 Vac connected in serial network brings to permanent damage of the driver.
PC pCO
24 Vac
20 VA
Fig. 2.j
230 Vac 24 Vac
NO!
20 VA
230 Vac
Installation environment
Important: avoid installing the drivers in environments with the following characteristics:
• relative humidity greater than 90% or with condensation;
• strong vibrations or knocks;
• exposure to continuous water sprays;
• exposure to aggressive and polluting atmospheres (e.g.: sulphur and ammonia fumes, saline mist, smoke) to avoid corrosion and/or oxidation;
• strong magnetic and/or radio frequency interference (therefore avoid installing the devices near transmitting antennae);
• exposure of the driver to direct sunlight and to the elements in general.
Important: the following warnings must be observed when connecting the driver:
• if the driver is used in a way that is not specified in this user manual, protection cannot be guaranteed;
• incorrect power connections may seriously damage the driver;
• use cable ends suitable for the corresponding terminals. Loosen each screw and insert the cable ends, then tighten the screws and gently tug the cables to check they are sufficiently tight;
• separate as much as possible (at least 3 cm) the probe and digital input cables from power cables to avoid possible electromagnetic disturbance. Never run power cables (including the electrical panel cables) and probe signal cables in the same conduits;
• do not run probe signal cables in the immediate vicinity of power devices (contactors, circuit breakers, etc.). Reduce the path of probe cables as much as possible, and avoid spiral paths that enclose power devices;
• avoid powering the controller directly from the main power supply in the panel if this supplies different devices, such as contactors, solenoid valves, etc., which will require a separate transformer;
• *EVD mini/ice is a controller to be incorporated into the final equipment; it must not be wall-mounted;
• * DIN VDE 0100: protective separation must be guaranteed between the SELV circuits (Safety Extra Low Voltage) and the other circuits. The requirements of DIN VDE 0100 must be complied with. To prevent disruption of the protective separation (between the SELV circuits and the other circuits) ensure additional fastening near the terminations.
This additional fastening must secure the insulation and not the wires.
2.5 Copy parameters with programming key
Note:
• The parameters must only be copied when the driver is NOT powered;
• also see the programming key technical leaflet, P/N +050003930.
Procedure:
A.
Open the cover on the key using a screwdriver;
B.
Set the microswitches based on the operation :
- UPLOAD: microswitches 2 = OFF,
- DOWNLOAD: microswitches 1= OFF,
microswitches 2 = ON
See leaflet +050003930
ENG
EV D mini (24 V)
Important: do not use a screwdriver to remove the cover on the display, to avoid damaging the board.
To remove the cover of the display:
1
2
3
Apply a pressure rightward on the left side of the cover.
Raise up the right side to extract it.
Plug the key into the provided connector, then perform the desired operation (UPLOAD/DOWNLOAD).
3
L
1 press
GAS Type
Mode
Super Heat press
2
Fig. 2.m
GAS Type
Mode
Super Heat
Fig. 2.l
EV D mini (230 V)
To remove the cover of the display:
1
2
3
Press with a screwdriver as shown in the figure, to remove the cover.
Lift the cover and remove it.
Plug the key into the provided connector, then perform the desired operation (UPLOAD/DOWNLOAD).
3
L
1 press
GAS Type
Mode
Super Heat
GAS Type
Mode
Super Heat press
2
A
Fig. 2.k
B
11 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
On models where featured, the user interface comprises the twodigit display and keypad with three buttons that, pressed alone or in combination, are used to perform all the configuration and programming operations on the driver.
Model without display
1 2
3. values less than -9 are displayed in two steps:
- first the “-“sign;
- then the tens and units.
GAS Type
123 --->
Mode
Super Heat
GAS Type
Mode
Super Heat
Fig. 3.a
1 Red LED - see “Alarms”
2 Green LED - power supply ON
GAS Type
-99 --->
Mode
Super Heat
GAS Type
Mode
Super Heat
The parameters can be modified using the front keypad. Access depends on the user level: basic parameters (first configuration/setup) and Service parameters (Installer).
Important: DO NO T change the control parameters before completing the commissioning wizard, as described in chapter 4.
Modifying the
S
ervice parameters
The Service parameters include, in addition to the parameters for the configuration of input S1, those corresponding to the network address, probe readings, protectors and manual positioning. See the param. table.
Procedure:
1. press UP and DOWN together and hold for more than 5 s: the first parameter is displayed: P1 = probe S1 reading;
2. press UP/ DOWN until reaching the desired parameter;
3. press PRG/ Set to display the value;
4. press UP/ DOWN to modify the value;
5. press PRG/ Set to confirm and return to the parameter code;
6. repeat steps 2 to 5 to modify other parameters;
7. (when the parameter code is displayed) press PRG/Set and hold for more than 2 s to exit the parameter setting procedure.
GAS Type
Fig. 3.c
Model with display
2
1
Mode
GAS Type
1 2
Super Heat
3
4
Fig. 3.b
Key
1 Parameter label (for commissioning)
2 Keypad
3 Control ON/OFF digital input status LED
4 flashing/off = DI closed/open (*)
Two-digit display
(*) when the digital input is closed, the LED flashes and control is activated.
During commissioning/setup, the parameter label shows the meaning of the segments displayed in the first digit, corresponding to the three parameters being set:
A.
GAS Type: type of refrigerant;
B . Mode: operating mode;
C . Superheat: superheat set point.
See the “Commissioning” chapter.
GAS Type GAS Type
GAS Type
Mode
Super Heat
Mode
Super Heat
Mode
Super Heat
Mode
Super Heat
A. Refrigerant B. Mode (operating mode) C. Superheat set point
3.1 Keypad
Key
/
UP DOWN
PRG/Set
Description
• Increases/decreases the value of the set point or other selected parameter
• menu navigation
• at the end of the commissioning procedure, press for 2 s to exit and activate control;
• enter/exit control mode, saving the parameters;
• reset alarm E8
Tab. 3.b
3.2 Display
During normal operation, the two-digit display shows the superheat measure and any alarms. If used as an analogue positioner, it displays the 0 to 10 V input value with decimal point. The display interval for the superheat value is -5 to 55 K (-9 to 99 °F). In general, values between -99 and 999 are displayed as follows:
1. values from 0 to 10 are displayed with decimal point and decimals;
2. values greater than 99 are displayed in two steps:
- first, the hundreds, followed by “H”
- then the tens and units.
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
12
Fig. 3.d
Note: if no button is pressed, after around 30 s the display automatically returns to standard visualisation.
3.4 Restore factory parameters (default)
It is possible restore the controller to the default settings.
Procedure: with the controller in standard display mode, press the three buttons together. After 5 seconds the display shows “rS”. The reset procedure can be confirmed within 10 seconds, by pressing PRG/SET buttons for 3 seconds. If no button is pressed during this time, the procedure will be cancelled. At the end, the controller displays two dashes and then awaits the commissioning parameters.
ENG
4. COMMISSIONING
4. Press PRG to save the setting and return to the refrigerant parameter code (bar at top) Note:
• If the controller does not have a display, see “Network connection”;
• the default pressure probe is the ratiometric probe, with a measurement range of -1…9.3 barg;
• note the unit of measure (K/°F) when setting the superheat set point. To change the unit of measure, see the “Functions” chapter.
GAS Type
Mode
Super Heat
Once the electrical connections have been completed (see the chapter
“Installation”) and the power supply has been connected, the operations required for commissioning the driver depend on the type of interface used, however essentially involve setting just 3 parameters: refrigerant, functioning mode , superheat setpoint.
Important:
• until the commissioning procedure has been completed, control will not be active;
• (only during commissioning) changing the refrigerant also means having to change the type of pressure probe.
Power on the driver: the display lights up and the driver awaits the commissioning parameters, as indicated by the bar on the display:
1. Refrigerant (default = 3: R404A);
2. Type of control (default = 1: multiplexed showcase/cold room);
3. Superheat set point (default= 11 K).
Procedure:
5. Press DOWN to move to the next parameter: Mode, indicated by the bar in the middle.
6. Repeat steps 2-4 to set superheat settings 1-7 and bypass 8-9;
GAS Type
Mode
Super Heat
7. Press DOWN to move to the next parameter. For the superheat set point, the bar at the bottom is shown. Set the superheat set point;
GAS Type
GAS Type
Mode
Super Heat
Mode
Super Heat
1. The display shows the bar at the top: refrigerant (GAS Type)
GAS Type
8. In the event of bypass control by pressure, parameter _P is shown.
Set the bypass pressure set point.
GAS Type
Mode
Super Heat
Mode
Super Heat
9. In the event of bypass control by temperature, parameter _t is shown. Set the bypass temperature set point.
2. Press PRG/Set to display the refrigerant setting
GAS Type
GAS Type
Mode
Super Heat
Mode
Super Heat
3. Press UP/DOWN to modify the value
GAS Type
10. Press PRG/Set for 2 s to save the settings, exit programming mode and activate control. The standard display is shown.
Mode
Super Heat
13 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
4.5 Initial configuration parameters
Important: ONLY DURING COMMISSIONING, changing the refrigerant also means having to change the type of ratiometric probe; if not specified in the table, the ratiometric probe type is (-1 ... 9.3 barg).
R
efrigerant
Parameter/ description
Gas Type = refrigerant
0 = Custom
1 R22
2 R134a
3 R404A
4 R407C
5 R410A
6 R507A
7 R290
8 R600
(-1...4.2 barg)
9 R600a
(-1...4.2 barg)
10 R717
11 R744
(0...45 barg)
12 R728
13 R1270
14 R417A
15 R422D
16 R413A
17 R422A
18 R423A
19 R407A
20 R427A
21 R245FA
22 R407F
23 R32
(0...17.3 barg)
24 HTR01
25 HTR02
26 R23
27 R1234yf
28 R1234ze (-1...4.2 barg)
29 R455A (-1...12.8 barg)
30 R170 (0...17.3 barg)
31 R442A (-1...12.8 barg)
32 R447A (-1...12.8 barg)
33 R448A
34 R449A
35 R450A (-1...4.2 barg)
36 R452A (-1...12.8 barg)
37 R508B (-1...4.2 barg)
38 R452B
39 R513A (-1...4.2 barg)
40 R454B
Def.
3 =
R404A
Note: if the refrigerant gas is not among those selectable for the
“GAS Type = refrigerant” parameter:
1. set any refrigerant (e.g. R404);
2. select the type of main control, the superheat set point and complete the initial commissioning procedure;
3. use the VPM program (Visual Parameter Manager, see the chapter
“Network connection”) and set the type of refrigerant: “0 = custom” and the “Dew point a...f high/low” parameters that define the refrigerant;
4. start control, for example by closing the digital input contact.
O
perating mode
Mode = Operating mode
1 Multiplexed showcase/cold room
2 Air-conditioner/chiller with plate heat exchanger
3 Air-conditioner/chiller with tube bundle heat exchanger
4 Air-conditioner/chiller with finned coil heat exchanger
5 Analogue positioner (0 to 10 V)
6 Superheat control with 2 temperature probes
7 Subcritical CO2 showcase/cold room
8 Hot gas bypass by pressure
9 Hot gas bypass by temperature
1 = Multiplexed showcase/ cold room
S
et point
Note: take into consideration the unit of measure (K/°F) when setting the superheat set point.
Superheat set point
Bypass pressure set point
Bypass temperature set point
11 K(20°F)
3 bar
10 °C
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
14
ENG
5. FUNCTIONS
5.1 Control
EVD mini is a superheat controller and can be used as an analogue positioner. The type of refrigeration unit can be selected using the
“Operating mode” parameter.
Parameter/description
Operating mode
1 Multiplexed cabinet/cold room
2 Air-conditioner/chiller with plate heat exchanger
3 Air-conditioner/chiller with tube bundle heat exchanger
4 Air-conditioner/chiller with finned coil heat exchanger
5 Analogue positioner (0 to 10 V)
6 Superheat control with 2 temperature probes
7 Subcritical CO2 showcase/cold room
8 Hot gas bypass by pressure
9 Hot gas bypass by temperature
Def.
1 = multiplexed cabinet/cold room
Tab. 5.a
Based on the operating mode setting , the driver automatically sets a series of control parameters.
Operating mode
1 Multiplexed cabinet/cold room 15
2 Air-conditioner/chiller with plate heat exchanger 3
3 Air-conditioner/chiller with tube bundle heat 5 exchanger
4 Air-conditioner/chiller with finned coil heat 10 exchanger
5 Analogue positioner (0 to 10 V)
6 Superheat control with 2 temperature probes
7 Subcritical CO2 showcase/cold room
8 Hot gas bypass by pressure
9 Hot gas bypass by temperature
-
15
20
20
15
PID: proport. gain
PID: integration time
150
40
60
Super- heat set point
11
6
6
LowSH protection threshold
5
2
2
Integration time
15
2,5
2,5
LOP protection MOP protection Bypass pressione: setpoint
(bar) threshold
-50
-50
-50
Integration time
0
4
4 threshold
50
50
50
Integration time
20
10
10
Bypass temperatura: setpoint
(°C)
100
-
150
400
200
150
6
-
11
13
-
-
2
-
5
7
-
-
10
-
15
15
-
-
-50
-
-50
-50
-
-
10
-
0
0
-
-
50
-
50
50
-
-
20
-
20
20
-
-
3
-
-
10
Tab. 5.b
S
uperheat
The primary purpose of the electronic valve is ensure that the flow-rate of refrigerant that flows through the nozzle corresponds to the flow-rate required by the compressor. In this way, the evaporation process will take place along the entire length of the evaporator and there will be no liquid at the outlet (consequently in the branch that runs to the compressor). As liquid is not compressible, it may cause damage to the compressor and even breakage if the quantity is considerable and the situation lasts some time.
S
uperheat control
The parameter that the control of the electronic valve is based on is the superheat temperature, which effectively tells whether or not there is liquid at the end of the evaporator. The superheat temperature is calculated as the difference between: superheated gas temperature
(measured by a temperature probe located at the end of the evaporator) and the saturated evaporation temperature (calculated based on the reading of a pressure transducer located at the end of the evaporator and using the Tsat(P) conversion curve for each refrigerant).
Superheat = Superheated gas temperature (*) – Saturated evaporation temperature
(*) suction
If the superheat temperature is high it means that the evaporation process is completed well before the end of the evaporator, and therefore flow-rate of refrigerant through the valve is insufficient. This causes a reduction in cooling efficiency due to the failure to exploit part of the evaporator. The valve must therefore be opened further.
Vice-versa, if the superheat temperature is low it means that the evaporation process has not concluded at the end of the evaporator and a certain quantity of liquid will still be present at the inlet to the compressor.
The valve must therefore be closed further. The operating range of the superheat temperature is limited at the lower end: if the flow-rate through the valve is excessive the superheat measured will be near 0 K. This indicates the presence of liquid, even if the percentage of this relative to the gas cannot be quantified. There is therefore un undetermined risk to the compressor that must be avoided. Moreover, a high superheat temperature as mentioned corresponds to an insufficient flow-rate of refrigerant. The superheat temperature must therefore always be greater than 0 K and have a minimum stable value allowed by the valve-unit system.
A low superheat temperature in fact corresponds to a situation of probable instability due to the turbulent evaporation process approaching the measurement point of the probes. The expansion valve must therefore be controlled with extreme precision and a reaction capacity around the superheat set point, which will almost always vary from 3 to 14 K.
Set point values outside of this range are quite infrequent and relate to special applications.
15 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
C
See chapter on “Protectors”.
C
L
CP
F
S
S2 S1
EVD mini
EV
V
M
T E
T
Fig. 5.a
Key
CP compressor
C condenser
L liquid receiver
F dewatering filter
S liquid indicator
EEV electronic expansion valve
V solenoid valve
E evaporator
P pressure probe (transducer)
T temperature probe
For the wiring, see “Wiring description”.
P
I
D
parameters
Superheat control uses a PID algorithm. The control output is calculated as the sum of separate contributions: proportional and integral.
• the proportional action opens or closes the valve proportionally to the variation in the superheat temperature. Thus the greater the K
(proportional gain) the higher the response speed of the valve. The proportional action does not consider the superheat set point, but rather only reacts to variations. Therefore if the superheat value does not vary significantly, the valve will essentially remain stationary and the set point cannot be reached;
• the integral action is linked to time and moves the valve in proportion to the deviation of the superheat value from the set point. The greater the deviations, the more intense the integral action; in addition, the lower the value of Ti ( integral time) , the more intense the action will be. The integral time, in summary, represents the intensity of the reaction of the valve, especially when the superheat value is not near the set point.
See the “EEV system guide” +030220810 for further information on calibrating PID control.
Par.
Description
Superheat Superheat set point
CP ti
PID proport. gain
PID integral time
Def.
Min.
Max.
UoM
11(20) LowSH: threshold 55 (99) K(°F)
15
150
0
0
800 -
999 s
Note: when selecting the type of Mode, the PID control values suggested by CAREL will be automatically set for each application.
ontrol parameters for protection functions
5.2 Analogue positioner (0-10 Vdc)
The valve will be positioned linearly depending on the value of the “0 to 10 V input for analogue valve positioning” read by input S2. There is no PID control nor any protection (LowSH, LOP, MOP), and no valve unblock procedure. The opening of digital input DI stops control, and consequently forces the valve closed, switching operation to standby.
0 ...10 Vdc
EV
S2 S1 T
A
100%
EVD mini
regulator
0%
0 10
Fig. 5.b
Vdc
Key:
EV Electronic valve A Valve opening
For the wiring see chap. 2: “Description of the terminals”.
Important: the pre-positioning and re-positioning procedures will not be performed. Manual positioning can in any case be enabled when control is active or in standby.
5.3 Superheat control with 2 temp. probes
P
The functional diagram is shown below. This type of control must be used with care, due to the lower precision of the temperature probe compared to the probe that measures the saturated evaporation pressure.
Parameter/ description
Mode = Operating mode
… 6 = Superheat control with 2 temperature probes
Def.
1 = Multiplexed showcase/ cold room
C
L
CP
F
S
S2 S1
EVD mini
EV
V
M
T E
T
Fig. 5.e
Key:
CP Compressor
C Condenser
L Liquid receiver
F Dewatering filter
T Temperature probe
S2 Suction temperature probe
V Solenoid valve
S Liquid indicator
EV Electronic valve
E Evaporator
S1 Evaporation temperature probe
For the wiring see chap. 2: “Description of the terminals”.
16 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
Par.
Description
Superheat Superheat set point
CP ti
PID: proportional gain
PID: integral time
Def Min
11(20) LowSH:
Max UOM
55(99) K
15
150 thresh.
0
0
800
999
s
ENG
Hot gas bypass by temperaturs
This function can be used for cooling capacity control. On a showcase, if the room temperature probe detects an increase in temperature, cooling capacity needs to increase, so the valve must close.
C
Hot gas bypass by pressure
This function can be used for cooling capacity control. If there is no request from circuit B, the compressor suction pressure decreases and the bypass valve opens, so as to deliver more hot gas and decrease circuit capacity.
C
F
S
L EV
S2 S1
EVD mini
CP
A
S
F
M
V1
L
T
V2
EV
E
S2 S1
EVD mini
CP
P
B
T
V2
E
M
V1
Key
CP compressor
C condenser
L liquid receiver
F filter-drier
S liquid sightglass
V1 solenoid valve
V2 thermostatic expansion valve
EV electronic valve
E evaporator
For the wiring see the “General connection diagram”.
This is PID without any protection (LowSH, LOP, MOP, see the chapter on Protectors), no valve unblock procedure and no auxiliary control functions. The function uses the hot gas bypass pressure probe read by input S1, compared against the “Hot gas bypass pressure set point”.
Control is reverse: as the pressure increases, the valve closes and viceversa.
Par.
Description
_P Hot gas bypass pressure set point
CP PID: proportional gain ti PID: integral time
Def Min
3 -20(290)
Max UOM
200(2900) bar(psig)
15 0
150 0
800
999
s
T
V2
E T
M
V1
Key
CP compressor
C condenser
L liquid receiver
F filter-drier
S liquid sightglass
V1 solenoid valve
V2 thermostatic expansion valve
EV electronic valve
E evaporator
For the wiring see the “General connection diagram”.
This is PID without any protection (LowSH, LOP, MOP, see the chapter on Protectors), no valve unblock procedure and no auxiliary control functions. The function uses the hot gas bypass temperature probe read by input S2, compared against the “Hot gas bypass temperature set point”. Control is reverse: as the temperature increases, the valve closes and vice-versa.
Par.
Description
_t Hot gas bypass temperature set point
CP PID: proportional gain ti PID: integral time
Def Min Max UOM
10 -85(-121) 200(392) °C(°F)
15 0
150 0
800
999
s
17
5.5 Special control function: smooth lines
Note: the Smooth_line parameter is only accessible via the supervisor.
The smooth lines function optimises evaporator capacity based on actual cooling demand, allowing more effective and stable control. The function completely eliminates traditional on/off control cycles, modulating the temperature exclusively using the electronic valve; superheat set point is controlled through a precise PI control algorithm based on the actual control temperature.
The master controller (connected via serial to EVD mini), through dynamic management of the Smooth_line parameter, modifies the superheat set point for management of the electronic expansion valve, from a minimum (SH_SET) to a maximum (SH_SET + Smooth_line): this consequently acts directly on the PID control algorithm that modifies the valve position. This is useful when the control temperature approaches the set point; the Smooth_line parameter is used to prevent the valve from closing, by reducing the evaporator’s cooling capacity.
In order to use this function, the digital input must be configured as
BACKUP. The Smooth_line parameter thus allows the control set point to be adjusted instantly.
In the event where there is no network connection, the Smooth_line parameter is reset so as to resume normal control (START/STOP from digital input and SH_SET as the superheat set point).
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
The main effects are:
• no swings in temperature and superheat due to the set point being reached;
• stable temperature and superheat control;
• maximum energy savings due to load stabilisation.
Par.
di
Description
DI configuration
1=start/stop - 2=control backup
Smooth_line A: superheat set point offset for smooth lines
Def. Min. Max. UOM
1 1 2 -
0 -99
(-55)
99
(55)
K/°F
S H_set+
S mooth_line
S H set t
Temp. set t
Key
SH set Superheat set point
Temp.set
Temperature set point t time
Note: the temperature setting based on the corresponding set point is managed by the master controller, while superheat control is managed by the EVD mini.
5.6 Control parameters for protection functions
See chapter on “Protectors”.
The other configuration parameters, to be set where necessary before starting the controller, concern:
• the type of ratiometric pressure/temperature probe;
• the serial address for network connection;
• the type of unit of measure;
• enabling change in type of control (Mode);
• the number of steps (480/960) to control valve position.
Type of pressure/temperature probe (par.
S
1)
S1 is used to select the type of ratiometric pressure or NTC probe.
Par. Description
S1 Type of probe S1
1 = -1…4.2 barg
2 = 0.4…9.3 barg
3 = -1…9.3 barg
4 = 0…17.3 barg
5 = 0.85…34.2 barg
6 = 0…34.5 barg
7 = 0…45 barg
8 = -1…12.8 barg
9 = 0…20.7 barg
10 = 1.86…43.0 barg
11 = NTC (-50…105°C)
12 = Ratiometric (OUT=0-5V) 0-60 barg
13 = Ratiometric (OUT=0-5V) 0-90 barg
14 = Remote pressure probe from RS485
Def.
Min.
Max. UOM
3 1 11 -
Note: the maximum and minimum limits for the pressure probe alarm can be set. See the parameter table.
N
etwork address (par. n1)
See chap. “Network connection”
Unit of measure (par.
S
i)
The unit of measure used by the driver can be selected:
• S.I. (°C, K, barg);
• Imperial (°F, psig).
Par. Description
Si Unit of measure
1=°C/K/barg
2=°F/psig
Def.
Min.
Max. UOM
1 1 2 -
Note: lthe unit of measure K or °F relates to degrees Kelvin or
Fahrenheit adopted for measuring the superheat and the related parameters.
When changing the unit of measure, all the values of the parameters saved on the driver and all the measurements read by the probes will be recalculated. This means that when changing the units of measure, control remains unaltered.
Example 1: The pressure read is 20 barg, this will be immediately converted to the corresponding value of 290 psig.
Example 2: The “superheat set point” parameter set to 10 K will be immediately converted to the corresponding value of 18 °F.
A
ccess to Mode parameter (par. I
A
)
To avoid accidental modification of the controller’s operating mode, it is possible to disable the access to the corresponding mode parameter
(mode).
Par. Description
IA Enable operating mode modification
0/1 = yes/ no
Def.
Min.
Max. UOM
0 0 1 -
N
umber of control steps (par. U3)
Total number of steps between the valve fully closed and fully open position
Par. Description
U3 Number of valve control steps
1 / 2 = 480/960 steps
Def.
Min.
Max. UOM
1 1 2 -
D
igital input
The digital input function can be set by parameter:
Par. Description di DI configuration
1=Start/stop control;
2=Control backup
Def.
1
Min.
1
Max. UOM
2 -
Start/Stop control:
• digital input closed: control activated;
• digital input open: driver in standby (see paragraph “Control status”);
Important: this setting excludes activation/deactivation of control from the network. See the next setting.
Control backup : when connected to a network, in the event of communication failures, the driver verifies the status of the digital input to determine whether control is activated or in standby.
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ENG
6. PROTECTORS
These are additional functions that are activated in specific situations that are potentially dangerous for the unit being controlled. They feature an integral action, that is, the action increases gradually when moving away from the activation threshold. They may add to or overlap (disabling) normal PID superheat control. By separating the management of these functions from PID control, the parameters can be set separately, allowing, for example, normal control that is less reactive yet much faster in responding when exceeding the activation limits of one of the protectors.
The integration time is set automatically based on the type of main control.
S H
Lo w_ S H_TH
6.1 Protectors
The protectors are 3:
• LowSH, low superheat;
• LOP, low evaporation temperature;
• MOP, high evaporation temperature;
The protectors have the following main features:
• activation threshold: depending on the operating conditions of the controlled unit, this is set in Service programming mode;
• integration time, which determines the intensity (if set to 0, the protector is disabled): set automatically based on the type of main control;
• alarm, with activation threshold (the same as the protector) and timeout (if set to 0 disables the alarm signal).
Note: The alarm signal is independent from the effectiveness of the protector, and only signals that the corresponding threshold has been exceeded. If a protector is disabled (null integration time), the relative alarm signal is also disabled.
Each protector is influenced by the proportional gain parameter (CP) of
PID superheat control. The higher is the value of CP, the more intensely the protection will react.
C
haracteristics of the protectors
Protection
LowSH
LOP
MOP
Reaction
Intense closing
Intense opening
Moderate closing
Reset
Immediate
Immediate
Controlled
Tab. 6.a
Reaction: summary description of the type of action in controlling the valve.
Reset: summary description of the type of reset following the activation of the protector. Reset is controlled to avoid swings around the activation threshold or immediate reactivation of the protector.
Note: all the alarms are generated after a fixed delay, as shown in the table:
Lo w_ S H
ON
O FF t
A
ON
O FF t
D
B t
Fig. 6.a
key:
SH Superheat A Alarm
Low_SH_TH Low_SH protection threshold D Alarm delay
Low_SH Low_SH protection t Time
B Alarm automatic reset
L
OP
(low evaporation pressure)
LOP= Low Operating Pressure
The LOP protection threshold is applied as a saturated evaporation temperature value so that it can be easily compared against the technical specifications supplied by the manufacturers of the compressors. The protector is activated so as to prevent too low evaporation temperatures from stopping the compressor due to the activation of the low pressure switch. The protector is very useful in units with compressors on board
(especially multi-stage), where when starting or increasing capacity the evaporation temperature tends to drop suddenly.
When the evaporation temperature falls below the low evaporation temperature threshold, the system enters LOP status and is the intensity with which the valve is opened is increased. The further the temperature falls below the threshold, the more intensely the valve will open. The integration time indicates the intensity of the action: the lower the value, the more intense the action.
Par. Description
C3 LOP protection: threshold
Def.
-50
(-58)
C4 LOP protection: integration time 0
Min.
-85
(-121)
0
Max.
MOP protec.: threshold
800 s
U.M.
C(°F)
The integration time is set automatically based on the type of main control.
Protectors
LowSH
LOP
MOP
Delay (s)
300
300
600
Low
S
H (low superheat)
The protector is activated so as to prevent the low superheat from causing the return of liquid to the compressor.
Par. Description Def.
Min.
Max.
C1
C2
LowSH protection: threshold
LowSH protection: integration time
5(9) -5(-9) Set point
15 0 superheat
800 s
U.M.
K(°F)
When the superheat value falls below the threshold, the system enters low superheat status, and the intensity with which the valve is closed is increased: the more the superheat falls below the threshold, the more intensely the valve will close. The LowSH threshold must be less than or equal to the superheat set point. The low superheat integration time indicates the intensity of the action: the lower the value, the more intense the action.
Note:
• the LOP threshold must be lower then the rated evaporation temperature of the unit, otherwise it would be activated unnecessarily, and greater than the calibration of the low pressure switch, otherwise it would be useless. As an initial approximation it can be set to a value exactly half-way between the two limits indicated;
• the protector has no purpose in multiplexed systems (showcases) where the evaporation is kept constant and the status of the individual electronic valve does not affect the pressure value;
• the LOP alarm can be used as an alarm to highlight refrigerant leaks by the circuit. A refrigerant leak in fact causes an abnormal lowering of the evaporation temperature that is proportional, in terms of speed and extent, to the amount of refrigerant dispersed.
19 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
T_ EVAP
L O P _TH
L O P
ON
O FF t
ALA R M
ON
O FF t
D
B t
Fig. 6.b
Key:
T_EVAP Evaporation temperature
LOP_TH Low evaporation temperature
LOP
B protection
LOP protection
Automatic alarm reset
D Alarm timeout
ALARM Alarm t Time
M
OP
(high evaporation pressure)
MOP= Maximum Operating Pressure.
The MOP protection threshold is applied as a saturated evaporation temperature value so that it can be easily compared against the technical specifications supplied by the manufacturers of the compressors. The protector is activated so as to prevent too high evaporation temperatures from causing an excessive workload for the compressor, with consequent overheating of the motor and possible activation of the thermal protector.
The protector is very useful in self-contained units if starting with a high refrigerant charge or when there are sudden variations in the load. The protector is also useful in multiplexed systems (showcases), as allows all the utilities to be enabled at the same time without causing problems of high pressure for the compressors. To reduce the evaporation temperature, the output of the refrigeration unit needs to be decreased.
This can be done by controlled closing of the electronic valve, implying superheat is no longer controlled, and an increase in the superheat temperature. The protector will thus have a moderate reaction that tends to limit the increase in the evaporation temperature, keeping it below the activation threshold while trying to stop the superheat from increasing as much as possible. Normal operating conditions will not resume based on the activation of the protector, but rather on the reduction in the refrigerant charge that caused the increase in temperature. The system will therefore remain in the best operating conditions (a little below the threshold) until the load conditions change.
Par. Description
C5 MOP protection threshold
C6 MOP protection integration time
Def.
50
(122)
20
Min.
Protection LOP: threshold
0
Max. U.M.
200 C(°F)
(392)
800 s
The integration time is set automatically based on the type of main control.
When the evaporation temperature rises above the MOP threshold, the system enters MOP status, superheat control is interrupted to allow the pressure to be controlled, and the valve closes slowly, trying to limit the evaporation temperature.
As the action is integral, it depends directly on the difference between the evaporation temperature and the activation threshold. The more the evaporation temperature increases with reference to the MOP threshold, the more intensely the valve will close. The integration time indicates the intensity of the action: the lower the value, the more intense the action.
T_ EVAP
M O P _TH
M O P _TH - 1 t
M O P
ON
O FF
P I D
ON
O FF t t
ALA R M
ON
O FF
Key:
T_EVAP Evaporation temperature
PID
MOP
D
PID superheat control
MOP protection
Alarm timeout
D
Fig. 6.c
t
MOP_TH MOP threshold
ALARM Alarm t Time
Important: the MOP threshold must be greater than the rated evaporation temperature of the unit, otherwise it would be activated unnecessarily. The MOP threshold is often supplied by the manufacturer of the compressor. It is usually between 10 °C and 15 °C.
If the closing of the valve also causes an excessive increase in the suction temperature (S2) above the set threshold – set via parameter (C7), not on the display - the valve will be stopped to prevent overheating the compressor windings, awaiting a reduction in the refrigerant charge. If the MOP protection function is disabled by setting the integral time to zero, the maximum suction temperature control is also deactivated.
Par. Description
C7 MOP protection: disabling threshold
Def.
Min.
Max.
U.M.
30 -85 200 °C (°F)
(86) (-121) (392)
At the end of the MOP protection function, superheat regulation restarts in a controlled manner to prevent the evaporation temperature from exceeding the threshold again.
20 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
Par.
Description
BASIC (INITIAL CONFIGURATION)
GAS Refrigerant
Type
1 R22
2 R134a
15 R422D
16 R413A
3 R404A
4 R407C
5 R410A
17
18
19
R422A
R423A
R407A
29
30
R455A (-1...12.8 barg)
R170 (0...17.3 barg)
31 R442A (-1...12.8 barg)
32 R447A (-1...12.8 barg)
33 R448A
6 R507A
7 R290
20 R427A 34 R449A
21 R245FA 35 R450A (-1...4.2 barg)
8 R600(-1...4.2 barg) 22 R407F
9 R600a (-1...4.2 barg) 23 R32
(0...17.3
36
37
R452A (-1...12.8 barg)
R508B (-1...4.2 barg) barg)
10 R717 24 HTR01
11 R744 (0...45 barg) 25 HTR02
12 R728
13
14
R1270
R417A
38
39
R452B
R513A (-1...4.2 barg)
26 R23 40 R454B
27 R1234yf 41 R458A
28 R1234ze
(-1...4.2 barg)
Mode Operating mode
1 Multiplexed cabinet/cold room
2 Air-conditioner/chiller with plate heat exchanger
3 Air-conditioner/chiller with tube bundle heat exchanger
4 Air-conditioner/chiller with finned coil heat exchanger
5 Analogue positioner (0 to 10 V)
6 Superheat control with 2 temperature probes
7 Subcritical CO2 showcase/cold room
8 Hot gas bypass by pressure
9 Hot gas bypass by temperature
Super Superheat set point
Heat
_P Hot gas bypass pressure set point
_t Hot gas bypass temperature set point
SERVICE
P1 Probe S1 reading
P2 Probe S2 reading tE Evaporation temperature (converted) tS Suction temperature
Po Valve opening
CP PID: proportional gain ti PID: integral time
C1 LowSH protection: threshold
C2 LowSH protection: integral time
C3 LOP protection: threshold
C4 LOP protection: integral time
C5 MOP protection: threshold
C6 MOP protection: integral time
C7 MOP protection: disabling threshold
C8
S1 n1
Low suction temperature alarm threshold
Type of probe S1
Ratiometric (OUT=0…5V)
1 = -1…4.2 barg 8 = -1…12.8 barg
2 = 0.4…9.3 barg
3 = -1…9.3 barg
4 = 0…17.3 barg
5 = 0.85…34.2 barg
6 = 0…34.5 barg
7 = 0…45 barg
9 = 0…20.7 barg
10 = 1.86…43.0 barg
11 = NTC (-50…105°C)
12 = Ratiometric (OUT=0-5V) 0-60 barg
13 = Ratiometric (OUT=0-5V) 0-90 barg
14 = Remote pressure probe from RS485
Network address
Def.
3
1
11
(20)
3
10
LowSH protection: threshold
-20(-
290)
-85(-
121)
55
(99)
K
(°F)
200(2900) barg
(psig)
200(392) °C(°F)
-
-
-85
(-290)
-85
-
-
(-121)
-85
(-121)
-85
-
15
150
5(9)
(-121)
0
0
0
-5
(-9)
15 0
-50(-58) -85(-
121)
0
50
(122)
20
30
(86)
-50
(-58)
3
0
LOP protection: threshold
0
-85
(-121)
-85
(-121)
1
200
(2900)
200
(392)
200
(392)
200
(392)
100
800
999
Superh. set point
800
MOP protection: threshold
800
200
(392)
800
200
(392)
200
(392)
11 barg
(psig)
°C(°F)/
(°F) s
°C
(°F)
(°F)
%
s
K
V
°C
(°F)
°C s
°C
(°F) s
°C
(°F)
°C
(°F)
-
A
A
A
A
A
A
A
A
I
A
A
A
I
A
A
A
A
A
A
10
23
22
15
16
9
22
21
R/W
R/W
3
1
11
17
12
13
14
6
7
4
R
R
R/W
R/W
R/W
R/W
R/W
R
R
R
2
0
10
144
11
12
13
5
6
3
14
15
R/W
R/W
R/W
17
19
18
14
16
18
17
141
R/W
R/W
R/W
R/W
99
Min.
1
1
1
Max.
41
9
99
UOM
-
-
-
Type
I
I
I
Carel Modbus® R/W
12
13
10
139 R/W
140 R/W
137 R/W
Note
21 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
Par.
Description n2 Baud rate (bit/s)
0 4800, 2 stop bit, parity none
1 9600, 2 stop bit, parity none
9 4800, 1 stop bit, parity even
10 9600, 1 stop bit, parity even
2 19200, 2 stop bit, parity none 11 19200, 1 stop bit, parity even
3 4800, 1 stop bit, parity none 12 4800, 2 stop bit, parity odd
4 9600, 1 stop bit, parity none 13 9600, 2 stop bit, parity odd
5 19200, 1 stop bit, parity none 14 19200, 2 stop bit, parity odd
6 4800, 2 stop bit, parity even
7 9600, 2 stop bit, parity even
8 19200, 2 stop bit, parity even
15 4800, 1 stop bit, parity odd
16 9600, 1 stop bit, parity odd
17 19200, 1 stop bit, parity odd
Si
IA
Unit of measure 1=°C/K/barg ¦ 2=°F/psig
Enable operating mode modification 0/1 = yes/no
U1 Enable manual valve positioning 0/1 = no/yes
U2 Manual valve position
U3 Valve control steps: 1/2 = 480/960 steps
U4 Valve opening at start-up (evaporator/valve capacity ratio)
Fr Firmware version di DI configuration
1=start/stop control rt
L1
2=control backup
Reserved
Pressure S1: MINIMUM alarm value
Def.
2
H1 Pressure S1: MAXIMUM alarm value
0
1
50
1.3
1
0
0
1
Min.
0
1
0
0
0
1
0
-
1
Max.
17
2
1
1
999
2
100
-
2
UOM
-
-
-
step
-
%
-
-
1
-1
1
-85
(-121)
9.3
Pressure
S1: MIN alarm value
200 (392) alarm value
1
Pressure
S1: MAX
barg
(psig) barg
(psig)
Type
I
I
I
D
I
I
I
A
I
A
A
Carel Modbus® R/W
20
16
15
11
7
11
19
9
18
20
21
147
143
142
10
134
138
146
8
145
19
20
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
R/W
R/W
Note
Tab. 7.a
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
22
ENG
The driver can be connected via a network connection to:
1. a computer running the VPM software, for setting the parameters before commissioning;
2. a pCO controller, loaded with the application program;
3. a PlantVisor/PlantVisorPRO supervisor, for remote monitoring and alarm detection.
USB
USB-485
Converter
VPM
*
8.1 RS485 serial configuration
n1 assigns to the controller an address for serial connection to a supervisory and/or telemaintenance system.
Par. Description n1 Network address n2 Baud rate (bit/s)
0 4800, 2 stop bit, parity none
1 9600, 2 stop bit, parity none
2 19200, 2 stop bit, parity none
3 4800, 1 stop bit, parity none
4 9600, 1 stop bit, parity none
5 19200, 1 stop bit, parity none
6 4800, 2 stop bit, parity even
7 9600, 2 stop bit, parity even
8 19200, 2 stop bit, parity even
9 4800, 1 stop bit, parity even
10 9600, 1 stop bit, parity even
11 19200, 1 stop bit, parity even
12 4800, 2 stop bit, parity odd
13 9600, 2 stop bit, parity odd
14 19200, 2 stop bit, parity odd
15 4800, 1 stop bit, parity odd
16 9600, 1 stop bit, parity odd
17 19200, 1 stop bit, parity odd
Def.
Min.
Max.
UoM
99 1 99 -
2 0 17 -
Important: all controllers connected in a serial network need to be set with the same communication parameters.
8.2 Network connection for commissioning via PC
Warnings:
• fasten the converter properly so as to prevent disconnection;
• complete the wiring without power connected;
• keep the CVSTDUMOR0 interface cables separate from the power cables (power supply);
• in compliance with standards on electromagnetic compatibility, a shielded cable suitable for RS485 data transmission is used.
The RS485 converter is used to connect a computer running the VPM software to the EVD mini driver via a serial network, for commissioning the controllers. The system allows a maximum of 99 units, with a maximum network length of 500 m. Connection requires the standard accessories (RS485-USB converter, CAREL P/N CVSTDUMOR0) and a 120 Ω terminating resistor to be installed on the terminals of the last connected controller. Connect the RS485 converter to controllers and make the connections as shown in the figure. To assign the serial address, see parameter n1. See the converter technical leaflets for further information.
* shield shield shield
Tx/Rx -
Tx/ Rx +
GND
EVD ice/mini
1
Tx/Rx -
Tx/ Rx +
GND
EVD ice/mini
2
Tx/Rx -
Tx/ Rx +
GND
EVD ice/mini
...n
Fig. 8.a
8.3 Visual parameter manager
Go to http://ksa.carel.com and follow the instructions below. Select in sequence:
1. “Software & Support”
2. “Configuration & Updating Softwares”
3. “Parametric Controller Software”
4. “Visual Parametric Manager”
A window will open with the possibility to download two files:
1. VPM_setup_X.Y.Z.W_full.zip: complete program;
2. X.Y.Z.W_VPM_Devices_Upgrade.zip: upgrade for supported devices;
If this is the first installation, select Setup full, otherwise Upgrade. The program installs automatically by running setup.exe.
Note: if choosing complete installation (Setup full), uninstall any previous versions of VPM.
P
rogramming
When opening the program, the device to be configured needs to be selected: EVD mini. The Home page then opens, offering the choice between starting a new project or opening an existing project. If using the program for the first time, choose new project.
23
Fig. 8.b
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
The following options are then available:
1. Directly access the list of parameters saved in EEPROM: select “RS485”;
The operations are performed in real time (ONLINE mode), at the top right set network address 99 and choose the guided procedure for USB port recognition, then go to “Device setup”;
8.4 Restore default parameters
To restore the default parameter values on the controller:
1. Establish an RS485 serial connection between the computer and the driver. The LEDs on the USB/RS485 converter will flash;
Fig. 8.c
2. Select the model from the range based on the firmware version and list of configuration parameters (EVDMINI0000E0X_R*.*). These operations are performed in OFFLINE mode.
Fig. 8.e
2. Select “Update device” and: a. Click button (A) to open the drop-down menu; b. Select the list of parameters corresponding to the controller’s firmware version: “EVDMINI***.hex”; c. Click “Update” to load the parameters to the list and immediately after restore the controller parameters to the default value.
Menu
The pages marked 1) can be accessed wither Online or Offline, while those marked 2) are Online only.
1
C
A
B
Fig. 8.f
3. Go to “Device setup”: the program automatically reads the default parameters saved on the controller.
2
8.5 Setup by direct copy
1. On the Home page select RS485 (rear connector);
Fig. 8.d
The operations that can be performed on the pages marked 1) depend on the first selection made.
Note: to access the Online help press F1.
Ref.
Home
Device setup
Description
Select operating mode Online o
RS485 (rear
Online
Read instant values of control parameters connector)
Offline o
Device model
Offline
Select Load to load a list of project parameters
(.hex), modify and save a
Setup summary new project.
Display the default values for the current list of parameters
Prepare custom setup See online help.
Update device
Upload firmware
Select list of parameters and then Upload to controller
Select firmware and
Upload
Synoptic and graphs Overview with position of probes and probe and superheat readings in real time
-
-
-
Tab. 8.b
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
24
2. Go to “Device setup”;
Fig. 8.g
Fig. 8.h
a. on the “Rapid configuration” page, set parameters “p_GAS_TYPE” = refrigerant and “p_SUPER_MAIN_REGULATION”= type of control;
ENG
C
reate the configuration file
1. Select the “Device setup” page;
2. Set the parameters by double clicking, as shown in the figure: a. on the “Rapid configuration” page, parameters “p_GAS_TYPE” = refrigerant and “p_SUPER_MAIN_REGULATION”= type of control; b. on the “Configuration” page, parameter “p_SH_SET”.
Fig. 8.i
b. on the “Configuration” page, set parameter “p_SH_SET”.
Fig. 8.j
3. Check whether there are other parameters that need to be set (see the “Functions” chapter);
4. Finally, select “Write” to copy the parameters to the controller.
Fig. 8.m
3. Save the list of parameters with a new name, for example “NEW_
NAME.hex”. To load and display a list saved by the user, select “Load” and navigate to the path where the file is saved. On the other hand, to load a list of parameters supplied by CAREL, select “Load” and navigate the following path:
Load o
Plugins o
Commissioning EVD mini o
TXT o
TXT32.
Fig. 8.k
8.6 Setup using configuration file
On the Home page select “Device model”.
Fig. 8.l
The setup procedure comprises three steps:
1. Create the configuration file;
2. Copy the configuration file to the controller;
3. Read the configuration file on the controller.
Save Load
C
opy the configuration file to the controller
Select “Update device” and: a. Click button (A) to open the drop-down menu;
C
A
NEW_NAME.hex
B
Fig. 8.n
b. Select the list of parameters corresponding to the project file created:
“NEW_NAME.hex”; c. Click “Update” to UPLOAD the parameters to the controller.
25
8.7 Read the configuration file on the controller
1. Go to the “Home” page and select RS485 (rear connector);
2. Go to “Device setup” to read the list of parameters on the controller and make sure the settings are correct.
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
8.8 Variables accessible via serial connection
Parameter
Reg_status
Machine_type_SPV
Hardware_code_SPV
EEV_Positions_steps
Protection_status
Sh_unit_power_percent
Man_posit_steps
Start_func_test
Func_test_2
Net_address
EEV_steps_doubling
Gas_type
Super_main_regulation
Description
Controller status
Type of unit
Hardware code
Valve position
Protection status
Cooling capacity
Manual valve position
Input variable in functional test
Generic variable to use in the functional test
LAN serial network address
Double valve steps
Refrigerant
Main control
3
1
99
1
Def.
0
0
0
0
0
0
0
0
0
Min
0
0
0
0
0
0
0
1
1
1
0
Max
20
32767
32767
999
5
100
999
0 30000
-32768 32767
99
2
23
9
Super_S1_probe_model
Inhibit_mode_setting
Unity_measure
PID_Ti
Par_Digin1_Config
Probe S1
Enable mode parameter setting
Unit of measure
PID: integral time
Digital input configuration
3
0
1
150
1
1
0
1
0
1
14
1
2
999
2
Start_eev_opening_ratio
Net setting
Reset Default(*)
Ultracella signature
Regulation type
Gas custom dew_a_h
Gas custom dew_a_l
Gas custom dew_b_h
Gas custom dew_b_l
Gas custom dew_c_h
Gas custom dew_c_l
Gas custom dew_d_h
Gas custom dew_d_l
Gas custom dew_e_h
Gas custom dew_e_l
Gas custom dew_f_h
Gas custom dew_f_l
Net_alarm
Emergency_closing_alarm
S1_alarm
S2_alarm
1=Start/stop control
2=Control backup
Valve position at start-up
Baud rate
Reset factory parameters
Reserved
Type of control
Dew point a high
Dew point a low
Dew point b high
Dew point b low
Dew point c high
Dew point c low
Dew point d high
Dew point d low
Dew point e high
Dew point e low
Dew point f high
Dew point f low
Network alarm
No power supply
Probe S1 alarm
Probe S2 alarm
0
0
1
50
2
0
0
100
17
-32768 32767
-32768 32767
1 9
-288 -32768 32767
-15818 -32768 32767
-14829 -32768 32767
16804 -32768 32767
-11664 -32768 32767
16416 -32768 32767
0
0
0
0
-23322 -32768 32767
-16959 -32768 32767
-16378 -32768 32767
15910
-2927
-32768
-32768
32767
32767
-17239 -32768 32767
0
0
0
0
1
1
1
1
Low_sh_alarm
LOP_alarm
MOP_alarm
Low_suct_alarm
Eeprom_alarm
Digin1_status
Manual_posit_enable
Incomplete closing alarm
Battery alarm
EVD_CAN_GO
S1_Alarm_enable
S2_Alarm_enable
EEV_Position_percent
SH_SH
Low_SH alarm
LOP alarm
MOP alarm
Low suction temperature alarm
EEPROM damaged
Digital input status
Enable manual valve
Emergency closing not completed
Battery alarm
Enable EVD control
Enable probe S1
Enable probe S2
Valve opening
Superheat
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-5
(-9)
0
0
0
0
0
0
Sh_Suct_temp
Sh_Evap_temp
Sh_Evap_pres
S1_Value
S2_Value
Suction temperature
Evaporation temperature
Evaporation pressure
Probe S1 reading
Probe S2 reading
0
0
0
0
0
-85(-121) 200(392)
-85(-121) 200(392)
-20(-290) 200(2900)
-85(-290) 200(2900)
-85(-121) 200(392)
Positioning_mode_volt
Firm_release
SH_Set
0-10 V input
Firmware version
Superheat set point
0
0
11
0
0
Low_
Sh_Threshold
0
-5(-9)
10
800
55(99)
PID_Kp
Low_sh_threshold
PID: proportional gain
Low superheat: threshold
15
5
800
Set point surrisc.
Low_sh_Ti
Lop_threshold
Low superheat: integral time
LOP: threshold
LOP: integral time
MOP: threshold
15 0 800
-50(-58) -85(-121) MOP_threshold
0 0 800 Lop_Ti
MOP_Threshold 200
(392)
MOP_Ti MOP: integral time 20 0 800
Low_Suct_alarm_threshold Low suction temperature alarm threshold -50(-58) -85(-121) 200(392)
Mop_Inhibition_threshold MOP: inhibition threshold
50
30 (86)
LOP_threshold
-85
(-121)
200
(392)
1
1
1
1
1
1
100
55
(99)
1
1
1
1
1
1
11
12
13
14
15
16
17
18
19
10
11
12
13
14
15
16
17
18
2
3
0
1
157
158
159
160
161
162
151
152
153
154
155
156
146
147
148
149
150
0
1
10
11
12
13
14
15
7
8
9
4
5
6
2
3
4
5
6
7
8
9
30
31
32
33
34
35
3
4
1
2
24
25
26
27
28
29
19
20
21
22
23
1
2
11
12
13
14
15
16
5
6
7
8
9
10
3
4
5
6
7
8
9
10
I
I
I
I
I
I
D
D
D
D
I
I
I
I
I
I
I
I
I
I
I
D
D
D
D
D
D
A
A
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Type Carel Modbus® R/W Notes
1
2
3
4
5
6
7
8
9
128
129
130
131
132
133
134
135
136
R
R
R
R
R
R/W
R/W
R/W
R/W par. U2
10
11
12
13
14
15
16
17
18
137
138
139
140
141
142
143
144
145
R/W par. n1
R/W par. U3
R/W Gas Type = refrigerant
R/W Mode = operating mode
R/W par. S1
R/W par. IA
R/W par. Si
R/W par. ti
R/W
R/W par. U4
R/W par. n2
R/W
R/W
R
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
R
R
R
R
R/W par. U1
R/W al. E8
R
R/W
R/W
R/W par. Po al. E6 al. E5 al. A1 al. A2 al. E3 al. E2 al. E1 al. E4 al. EE
R
R
R par. tS
R
R par. P1 par. P2
R
R par. Fr
R/W Super heat = superheat set point
R/W par. CP
R/W par. C1
R/W par. C2
R/W par. C3
R/W par. C4
R/W par. C5
R/W par. C6
R/W par. C8
R/W
26 “EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
Parameter
S1_Alarm_threshold_ low
S1_Alarm_threshold_ high
Description
Pressure S1: MINIMUM alarm value
Pressure S1: MAXIMUM alarm value
TCTRL_REV_SET Hot gas bypass temperature set point 10
PCTRL_REV_SET Hot gas bypass pressure set point 3
SH_actual_set
SH_Set_smooth_line
Reserved
Superheat set point offset for smooth
S1_value_remote lines
S1 probe reading from supervisor
(*) set to 1973 to reset the parameters to the default values
0
0
0
Def.
-1
9.3
Min Max
-85(-290) Par_S1_
Alarm_threshold _ high
200(2900) Par_
S1_Ala rm_threshold _ low
-85
(-121)
200
(392)
-20
(-290)
-40(-72)
-55(-99)
200
(2900)
180(324)
55(99)
A
-20(-290) 200(2900) A
A
A
A
A
Type Carel Modbus® R/W Notes
A 20 19 R/W
21
22
23
24
25
26
20
21
22
23
24
25
R/W
R/W par. _t
R/W par. _P
R
R/W
R/W
Tab. 8.c
The electronic valve controller can have six different control states, each of which may correspond to a specific phase in the operation of the refrigeration unit and a certain status of the driver-valve system. The states are as follows:
• forced closing: initialisation of the valve position when switching the instrument on;
• standby: no temperature control, unit OFF (at temp.);
• wait: opening of the valve before starting control, also called prepositioning, when powering the unit on;
• control: effective control of the electronic valve, unit ON;
• positioning: step-change in the valve position, corresponding to the start of control when the cooling capacity of the controlled unit varies
(only EVD connected to a pCO);
• stop: of control with closing of the valve, corresponds to the end of temperature control of the refrigeration unit, unit OFF (at temp.).
F
orced closing
Forced closing is performed after the driver is powered on and corresponds to the typical number of closing steps for CAREL E2V and E3V unipolar valves.
This is used to realign the valve to the physical position corresponding to completely closed. The driver and the valve are then ready for control and both aligned at 0 (zero). At power-on, first a forced closing is performed, and then the standby phase starts. The valve is also closed in the event of a mains power failure if the Ultracap module is connected. In this case, the
“Forced valve closing not completed” parameter is set to 1. On restarting, if the valve forced closing procedure is not completed successfully:
1. the Master programmable controller (pCO) will check the value of the parameter, and if equal to 1 will decide the best strategy to adopt, based on the application;
2. on restarting the driver positions the valve as explained in the paragraph “Pre-positioning/start control”. The parameter is set to 0
(zero) by the Master controller (e.g. pCO), or alternatively by pressing the PRG/Set button on the keypad. Once the parameter has been set to 1, the driver sets it back to 0 (zero) only if an emergency forced closing procedure is completed successfully.
Note: lthe user can only select the resolution of the valve control signal: 480 or 960 steps.
Par. Description
U3 Valve control steps
1 / 2 = 480/ 960 steps
Def.
Min.
Max. UoM
1 1 2 -
S
tandby
Standby corresponds to a situation of rest in which no signals are received to control the electronic valve: it is closed and manual positioning can be activated. This status is normally set on the driver when the refrigeration unit is shutdown manually (e.g. from the supervisor) or when reaching the control set point. It can also occur when opening the digital input (which involves closing the valve) or in the event of a probe alarm. In general, it can be said that the electronic valve driver is in standby when the compressor stops or the control solenoid valve closes.
27
P
re-positioning/start control
If during standby a control request is received, before starting control the valve is moved to a precise initial position. Internally, the pre-positioning time is set at 6 s and represents the time that the valve is held in a fixed position. By default the valve is opened 50 % when starting (from digital input), so as to minimise the movement needed to reach the correct position.
Par. Description
U4 Valve opening at start-up
Def.
Min.
50 0
Max.
UoM
100 %
This parameter should be set based on the ratio between the rated cooling capacity of the evaporator and the valve (e.g. rated evaporator cooling capacity: 3kW, rated valve cooling capacity: 10kW, valve opening
= 3/10 = 33%).
The driver calculates the valve opening based on the required capacity:
If required capacity is 100%:
Opening (%)= (Valve opening at start-up);
If required capacity is less than 100% (capacity control):
Opening (%)= (Valve opening at start-up) x (Current unit cooling capacity), where the current unit cooling capacity is sent to the driver via RS485 by the pCO controller. If the driver is stand-alone, this is always equal to 100%.
Notes:
• this procedure is used to anticipate the movement and bring the valve significantly closer to the operating position in the phases immediately after the unit is powered on;
• if there are problems with liquid return after the refrigeration unit starts or in units that frequently switch on-off, the valve opening at start-up must be decreased. If there are problems with low pressure after the refrigeration unit starts, the valve opening must be increased.
W
ait
When the calculated position has been reached, regardless of the time taken
(this varies according to the type of valve and the objective position), there is a constant 5 second delay before the actual control phase starts. This is to create a reasonable interval between standby, in which the variables have no meaning, as there is no flow of refrigerant, and the effective control phase.
C
ontrol
The control request can be received by the closing of the digital input or via network (RS485). The solenoid or the compressor are activated when the valve, following the pre-positioning procedure, has reached the calculated position. The following figure represents the sequence of events for starting control of the refrigeration unit.
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
ENG
A
ON
O FF
S
ON
O FF t
P
ON
O FF t
R
ON
O FF t
T1 W t
Fig. 8.o
Key:
A Control request
P Pre-positioning
S Standby
R Control
T1 Pre-positioning time
W Wait (wait) t Time
Positioning (change cooling capacity)
This control status is only valid for controllers connected to the pCO via RS485. If there is a change in unit cooling capacity of at least 10%, sent from the pCO via RS485, the valve is positioned proportionally. In practice, this involves repositioning starting from the current position in proportion to how much the cooling capacity of the unit has increased or decreased in percentage terms. When the calculated position has been reached, regardless of the time taken, there is a constant 5 second delay before the actual control phase starts.
Note: if information is not available on the variation in unit cooling capacity, this will always be considered as operating at 100% and therefore the procedure will never be used. In this case, the PID control must be more reactive (see the chapter on Control) so as to react promptly to variations in load that are not communicated to the driver.
A
ON
OFF
t
C
ON
OFF
t
NP
ON
OFF
t
R
ON
OFF
Key:
A Control request
C Change in capacity
NP Repositioning
W Wait
t
T3
Fig. 8.p
W
R Control
T3 Repositioning time t Time
S
top/end control
The stop procedure involves closing the valve from the current position until reaching 0 steps, plus a further number of steps so as to guarantee complete closing. Following the stop phase, the valve returns to standby.
A
ON
OFF
S
ON
OFF
ST
ON
OFF
R
ON
OFF t t t
Key:
A Control request
S Standby
ST Stop
T4
Fig. 8.q
R Control
T4 Stop position time t Time t
8.10 Special control states
As well as normal control status, the driver can have three special states related to specific functions:
• manual positioning: this is used to interrupt control so as to move the valve, setting the desired position;
• recover physical valve position: recover physical valve steps when fully opened or closed;
• unblock valve: forced valve movement if the driver considers it to be blocked.
Manual positioning
Manual positioning can be activated at any time during the standby or control phase. Manual positioning, once enabled, is used to freely set the position of the valve using the corresponding parameter.
Control is placed on hold, all the system and control alarms are enabled, however neither control nor the protectors can be activated. Manual positioning thus has priority over any driver state/protector.
Par. Description Def.
Min.
Max. UoM
0 1 -
0/1=yes/no
U2 Manual valve position 0 0 999 step
Notes:
1. the manual positioning status is NOT saved when restarting after a power failure.
2. in for any reason the valve needs to be kept stationary after a power failure, proceed as follows:
• remove the valve stator;
• set the PID proportional gain =0. The valve will remain stopped at the initial opening position, set by corresponding parameter
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28
R
etrieve physical valve position
This procedure is necessary as the stepper motor intrinsically tends to lose steps during movement. Given that the control phase may last continuously for several hours, it is probable that from a certain time on the estimated position sent by the valve driver does not correspond exactly to the physical position of the movable element. This means that when the driver reaches the estimated fully closed or fully open position, the valve may physically not be in that position. The “Synchronisation” procedure allows the driver to perform a certain number of steps in the suitable direction to realign the valve.
Note: realignment is in intrinsic part of the forced closing procedure and is activated whenever the driver is stopped/started and in the standby phase.
Unblock valve
This procedure is only valid when the driver is performing superheat control. Unblock valve is an automatic safety procedure that attempts to unblock a valve that is supposedly blocked based on the control variables (superheat, valve position). The unblock procedure may or may not succeed depending on the extent of the mechanical problem with the valve. If for 10 minutes the conditions are such as to assume the valve is blocked, the procedure is run a maximum of 5 times. The symptoms of a blocked valve do not necessarily mean a mechanical blockage. They may also represent other situations:
• mechanical blockage of the solenoid valve upstream of the electronic valve (if installed);
• electrical damage to the solenoid valve upstream of the electronic valve;
• blockage of the filter upstream of the electronic valve (if installed);
• electrical problems with the electronic valve motor;
• electrical problems in the driver-valve connection cables;
• incorrect driver-valve electrical connection;
• incorrect driver-valve electrical connection;
• electronic problems with the valve control driver;
• secondary fluid evaporator fan/pump malfunction;
• insufficient refrigerant in the refrigerant circuit;
• refrigerant leaks;
• lack of subcooling in the condenser;
• electrical/mechanical problems with the compressor;
• processing residues or moisture in the refrigerant circuit.
Note: the valve unblock procedure is nonetheless performed in each of these cases, given that it does not cause mechanical or control problems. Therefore, also check these possible causes before replacing the valve.
ENG
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ENG
9. ALARMS
9.1 Types of alarms
There are two types of alarms:
• system: EEPROM, probe and communication;
• control: low superheat, LOP, MOP, low suction temperature.
The activation of the alarms depends on the setting of the threshold and activation delay parameters. The EEPROM unit parameters and operating parameters alarm always shuts down the controller and cannot be reset.
All the alarms are reset automatically, once the causes are no longer present, except for the “Emergency closing not completed” alarm, which requires manual reset.
Example 1: the board without display has the red
1 alarm is active. For EEPROM alarms, it stays on steady.
flashing when an
These are alarms that are only activated during control.
P
rotector alarms
The alarms corresponding to the LowSH, LOP and MOP protectors are only activated during control when the corresponding activation threshold is exceeded, and only when the delay time defined by the corresponding parameter has elapsed. If a protector is not enabled (integral time= 0 s), no alarm will be signalled. If before the expiry of the delay, the protector control variable returns back inside the corresponding threshold, no alarm will be signalled.
Note: this is a likely event, as during the delay, the protection function will have an effect.
1
Fig. 9.a
The probe alarms are part of the system alarms. When the value measured by one of the probes is outside of the range of measurement, an alarm is activated. The alarm limits correspond to the range of measurement.
In the event of a probe alarm, the driver closes the valve, regardless of digital input status, until the error is no longer present.
Example: the display shows probe alarms A1 and A2 in sequence. The superheat value has exceeded the maximum limit allowed, and this is indicated by the two top segments.
Low suction temperature alarm
The low suction temperature alarm is not linked to any protection function.
It features a threshold and a fixed delay (300 seconds), and is useful in the event of probe or valve malfunctions to protect the compressor using the relay to control the solenoid valve or to simply signal a possible risk.
In fact, incorrect measurement of the evaporation pressure or incorrect configuration of the type of refrigerant may mean the superheat calculated is much higher than the actual value, causing an incorrect and excessive opening of the valve. A low suction temperature measurement may in this case indicate probable flooding of the compressor, with corresponding alarm signal. The alarm is reset automatically, with a fixed differential of 3°C above the activation threshold.
Par. Description
C8 Low suction temperature alarm threshold
Def.
-50
(-58)
Min.
-85
(-121)
Max.
200
(392)
UoM
°C(°F)
GAS Type
Mode
Super Heat
GAS Type
Mode
Super Heat
GAS Type
Mode
Super Heat
Fig. 9.b
Minimum and maximum superheat limits
If a probe alarm occurs, it may be due to the superheat value exceeding the allowed display range -5…55 K (-9 to 99°F). The display therefore shows the probe alarm code (A1/A2) and:
1. if the superheat value is less than -5K, the display shows the two bottom segments;
2. if the superheat value is higher than 55K, the display shows the two top segments.
GAS Type GAS Type
9.4 Valve emergency closing procedure
The following description only applies if EVD mini is connected to the
Ultracap module.
In the event of a power failure, EVD mini can provide emergency closing of the valve, thus preventing any refrigerant from flowing to the compressor.
In this situation, the driver generates two alarms: E8 and E5. If the procedure concludes successfully (the valve closes completely), alarm E8 is cleared, however alarm E5 continues until the Ultracap module is able to power on the driver.
• E8: failed emergency closing (incomplete closing alarm). Active during the emergency closing stage and until the valve closes completely, after which alarm E8 is cleared. If the closing procedure is not completed (e.g. because the Ultracap module does not have enough charge), when next restarting the controller, the user must manually reset the alarm (pressing the PRG/SET button or setting the corresponding parameter to zero via serial connection);
• E5: emergency closing (emergency force closing alarm). This depends on a controller power failure and indicates that the emergency procedure is in progress.
Mode
Super Heat
1
Fig. 9.c
Mode
Super Heat
2
Notes:
• if the voltage measured falls below a certain threshold, the controller, connected to the Ultracap module, can start the valve emergency closing procedure;
• during the valve emergency closing procedure, the display is switched off to save energy (therefore the alarms may not be shown on the display, or only shown for a brief instant);
• if power returns during the closing procedure, alarms E8 and E5 are reset and closing is completed in any case.
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The digital input configuration parameter can only be set to control backup from the supervisor. If there is a communication error between the pCO controller and driver, the digital input status determines whether to continue control (input closed = the valve remains in the current position) or stop (input open).
E8
EE
E6
E7
E1
E2
E3
E4
E5
Alarm code on the display
A1
Red LED flashes
A2 flashes flashes flashes flashes flashes flashes flashes flashes flashes on steady
Cause of the alarm
Probe S1 faulty or set alarm range exceeded
Probe S2 faulty or set alarm range exceeded
MOP protection activated
LOP protection activated
LowSH protection activated
Reset automatic automatic automatic automatic automatic
Low suction temperature
Chiusura di emergenza: LowSH,
LOP, MOP, bassa T/P di aspirazione, mancanza di alimentazione
Network error automatic automatic automatic
Ultracap module powered at low voltage or low charge automatic
Effects on control
Valve closed
Valve closed
Protection action already in progress
Protection action already in progress
Protection action already in progress
No effect
Valve closed
Control based on DI
No effect
Emergency closing not completed Manual Valve closed
EEPROM operating and/or unit parameters damaged
Replace the driver/ Contact service
Total shutdown
Checks / Solutions
Check the probe connections.
Check the probe connections.
Check parameter “MOP protection: threshold”
Check parameter “LOP protection: threshold”
Check parameter “LowSH protection: threshold”
Check the threshold parameter.
Reset power supply
Check the wiring and that the pCO is on and operating
Check the wiring, the power supply and that the minimum recharge time has elapsed
Press PRG/Set or set the corresponding supervisor variable to 0
Replace the driver/Contact service
Tab. 9.d
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10. TROUBLESHOOTING
The following table lists a series of possible malfunctions that may occur when starting and operating the driver and the electronic valve. These cover the most common problems and are provided with the aim of offering an initial response for resolving the problem.
PROBLEM
The superheat value measured is incorrect
Liquid returns to the compressor during control
Liquid returns to the compressor only after defrosting
(for multiplexed cabinets only)
Liquid returns to the compressor only when starting the controller (after being
OFF)
CAUSE SOLUTION
The probe does not measure correct values Check that the pressure and the temperature measured are correct and that the probe
The type of refrigerant set is incorrect
The superheat set point is too low
Low superheat protection ineffective position is correct. Make sure the correct pressure probe has been set. Check the correct probe electrical connections.
Check and correct the type of refrigerant parameter.
Increase the superheat set point. Initially set it to 11 K and check that there is no longer return of liquid. Then gradually reduce the set point, always making sure there is no return of liquid.
If the superheat remains low for too long with the valve that is slow to close, increase the low superheat threshold and/or decrease the low superheat integration time.
Initially set the threshold 3 °C below the superheat set point, with an integration time of 3-4 seconds. Then gradually lower the low superheat threshold and increase the low superheat integration time, checking that there is no return of liquid in any operating
Stator broken or connected incorrectly
Valve stuck open conditions.
Disconnect the stator from the valve and the cable and measure the resistance of the windings using an ordinary tester.
The resistance of both should be around 40 ohms. Otherwise replace the stator.
Check if the superheating is always low (<2 °C) with the valve position permanently at
0 steps. If so, set the valve to manual control and close it completely. If the superheat is always low, check the electrical connections and/or replace the valve.
Decrease the value of the “Valve opening at start-up” parameter on all the utilities, making sure that there are no repercussions on the control temperature.
The “valve opening at start-up” parameter is too high on many cabinets in which the control set point is often reached (for multiplexed cabinets only)
The superheat temperature measured by the driver after defrosting and before reaching operating conditions is very low
Check that the LowSH threshold is greater than the superheat value measured and that the corresponding protection is activated (integration time >0 s). If necessary, decrease the value of the integration time.
for a few minutes
The superheat temperature measured by the driver does not reach low values, but
Set more reactive parameters to bring forward the closing of the valve: increase the proportional factor to 30, increase the integration time to 250 s.
there is still return of liquid to the compressor rack
Many cabinets defrosting at the same time Stagger the start defrost times. If this is not possible, if the conditions in the previous
The valve is significantly oversized
The “valve opening at start-up” parameter is set too high two points are not present, increase the superheat set point and the LowSH thresholds by at least 2 °C on the cabinets involved.
Replace the valve with a smaller equivalent.
Check the calculation in reference to the ratio between the rated cooling capacity of the evaporator and the capacity of the valve; if necessary, lower the value.
The superheat value swings around the set point with an amplitude greater than 4°C
In the start-up phase with high evaporator temperatures, the evaporation pressure is high
The condensing pressure swings
The superheat swings even with the valve set in manual control (in the position corresponding to the average of the working values)
The superheat does NOT swing with the valve set in manual control (in the position corresponding to the average of the working values)
The superheat set point is too low
Check the controller condenser settings, giving the parameters “blander” values (e.g. increase the proportional band or increase the integration time). Note: the required stability involves a variation within +/- 0.5 bars. If this is not effective or the settings cannot be changed, adopt electronic valve control parameters for perturbed systems
Check for the causes of the swings (e.g. low refrigerant charge) and resolve where possible.
As a first approach , decrease (by 30 to 50 %) the proportional factor. Subsequently try increasing the integration time by the same percentage. In any case, adopt parameter settings recommended for stable systems.
MOP protection disabled or ineffective
Refrigerant charge excessive for the system or extreme transitory conditions at start-up
(for cabinets only).
Increase the superheat set point and check that the swings are reduced or disappear.
Initially set 13 °C, then gradually reduce the set point, making sure the system does not start swinging again and that the unit temperature reaches the control set point.
Activate the MOP protection by setting the threshold to the required saturated evaporation temperature (high evaporation temperature limit for the compressors) and setting the MOP integration time to a value above 0 (recommended 4 seconds). To make the protection more reactive, decrease the MOP integration time.
Apply a “soft start” technique, activating the utilities one at a time or in small groups. If this is not possible, decrease the values of the MOP thresholds on all the utilities.
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PROBLEM
In the start-up phase the low pressure protection is activated (only for selfcontained units)
CAUSE
The “Valve opening at start-up” parameter is set too low
The driver in RS485 network does not start control and the valve remains closed
The driver in stand-alone configuration does not start control and the valve remains closed
LOP protection disabled
LOP protection ineffective
SOLUTION
Check the calculation in reference to the ratio between the rated cooling capacity of the evaporator and the capacity of the valve; if necessary lower the value.
Check the serial connection. Check that the pCO application connected to the driver
(where featured) correctly manages the driver start signal. Check that the driver is NOT in stand-alone mode.
Check the connection of the digital input. Check that when the control signal is sent that the input is closed correctly. Check that the driver is in stand-alone mode.
Solenoid blocked
Insufficient refrigerant
The valve is connected incorrectly (rotates in reverse) and is open
Stator broken or connected incorrectly
Valve stuck closed
Set a LOP integration time greater than 0 s.
Make sure that the LOP protection threshold is at the required saturated evaporation temperature (between the rated evaporation temperature of the unit and the corresponding temperature at the calibration of the low pressure switch) and decrease the value of the LOP integration time.
Check that the solenoid opens correctly, check the electrical connections.
Check that there are no bubbles in the sight glass upstream of the expansion valve.
Check that the subcooling is suitable (greater than 5 °C); otherwise charge the circuit.
Check the movement of the valve by placing it in manual control and closing or opening it completely. One complete opening must bring a decrease in the superheat and vice-versa. If the movement is reversed, check the electrical connections.
Disconnect the stator from the valve and the cable and measure the resistance of the windings using an ordinary tester.
The resistance of both should be around 40 ohms. Otherwise replace the stator.
Use manual control after start-up to completely open the valve. If the superheat remains high, check the electrical connections and/or replace the valve.
The unit switches off due to low pressure during control
(only for self-contained units)
LOP protection disabled
LOP protection ineffective
Solenoid blocked
Insufficient refrigerant
The valve is significantly undersized
Stator broken or connected incorrectly
Valve stuck closed
Set a LOP integration time greater than 0 s.
Make sure that the LOP protection threshold is at the required saturated evaporation temperature (between the rated evaporation temperature of the unit and the corresponding temperature at the calibration of the low pressure switch) and decrease the value of the LOP integration time.
Check that the solenoid opens correctly, check the electrical connections and the operation of the control relay.
Check that there are no bubbles of air in the liquid indicator upstream of the expansion valve. Check that the subcooling is suitable (greater than 5 °C); otherwise charge the circuit.
Replace the valve with a larger equivalent.
Disconnect the stator from the valve and the cable and measure the resistance of the windings using an ordinary tester.
The resistance of both should be around 40 ohms. Otherwise replace the stator.
Use manual control after start-up to completely open the valve. If the superheat remains high, replace the valve body.
The cabinet does not reach the set temperature, despite the value being opened to the maximum (for multiplexed cabinets only)
Solenoid blocked
Insufficient refrigerant
The valve is significantly undersized
Stator broken or connected incorrectly
Valve stuck closed
Check that the solenoid opens correctly, check the electrical connections and the operation of the relay.
Check that there are no bubbles of air in the liquid indicator upstream of the expansion valve. Check that the subcooling is suitable (greater than 5 °C); otherwise charge the circuit.
Replace the valve with a larger equivalent.
Disconnect the stator from the valve and the cable and measure the resistance of the windings using an ordinary tester.
The resistance of both should be around 40 Ω. Otherwise replace the stator.
Use manual control after start-up to completely open the valve. If the superheat remains high, replace the valve body.
The cabinet does not reach the set temperature, and the position of the valve is always 0 (for multiplexed cabinets only)
The driver in RS485 network does not start control and the valve remains closed
The driver in stand-alone configuration does not start control and the valve remains closed
Check the network connections. Check that the pCO application connected to the driver (where featured) correctly manages the driver start signal. Check that the driver is
NOT in stand-alone mode.
Check the connection of the digital input. Check that when the control signal is sent that the input is closed correctly. Check that the driver is in stand-alone mode.
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11. TECHNICAL SPECIFICATIONS
Power supply
EVD mini (24 V)
1. 24 Vac (+10/-15%) 50/60 Hz.
• Use a class II isolating transformer (min 20VA, max 50VA)
• Length of connection between transformer and EVDmini
Lmax=1 m
EVD mini (230 V)
115…230 Vac (+10/-15%) 50/60 Hz
• Length of power supply cable: Lmax=1 m.
Max power consumption (W)
Emergency power supply
Driver
Connections:
Motor connection
Digital inputs connection
Probes
Power to active probes (V REF)
RS485 serial connection
Assembly
Connectors
Dimensions
Operating conditions
Storage conditions
Index protection
Environmental pollution
Resistance to heat and fire
Overvoltage category
Insulation class
Class and software structure
Conformity
Electrical safety
Electromagnetic compatibility
• Use an external 24 Vdc power supply, min 15 W
13 15
13 Vdc +/-10% (If the optional Ultracap module for EVD mini is installed)
Unipolar valve
S1
S2
6-wire cable type AWG 18/22, Lmax=1m (see NOTE)
Digital input to be activated from voltage-free contact or transistor to GND.
Digital input 230 Vac optoisolated
Closing current: 10 mA
Closing current: 5mA.
Maximum contact resistance: <50Ω
Lmax=10 m for residential/industrial, 2 m for domestic environments
Lmax=10 m for residential/industrial, 2 m for domestic environments
Low temperature NTC:
Ratiometric pressure probe (0…5V)
10 kΩ a 25°C, -50T90°C
Measurement error: 1°C in the range -50T50°C; 3°C in the range +50T90°C
Resolution 0,1 % fs
Measurement error: 2% fs maximum; 1% typical
Low temperature NTC:
Input 0…10V
(max 12V)
+5Vdc+/-2%
Modbus, Lmax=500 m, shielded cable, earth both ends of the cable shield on DIN rail or with screws
Base x height x depth = 88 x 90 x 33 mm
III
10kΩ a 25°C, -50T90°C
Measurement error: 1°C in the range -50T50°C; 3°C in the range +50T90°C
Resolution 0,1 % fs
Measurement error: 9% fs maximum; 8% typical on DIN rail wire size 0,35...2,5 mm 2 (12...22 AWG)
Base x height x depth = 70,4 x 114 x 38 mm
-25T60°C; <90% U.R. non-condensing
-35T60°C, <90% U.R. non-condensing
IP00
2
Category D
Category II
II
A
EN 60730-1, UL 60730-1, UL 60730-2-9
EN 61000-6-1, EN 61000-6-2, EN 61000-6-3, EN 61000-6-4
EN61000-3-2, EN55014-1, EN61000-3-3
Note: if using in domestic and/or residential environments
(EN55014-1/EN61000-6-3) with the controller not installed inside a metallic panel, fit the ferrite (P/N 0907879AXX ):
• for EVD mini 24 V: applied on the valve stator cable if using in domestic/ residential environments with valve cable > 0.5 m;
• for EVD mini 115/ 230 V: applied on the valve stator cable if using in domestic/residential environments with valve cable > 0-4 m.
“EVD mini” +0300036EN - rel. 1.2 - 23.04.2018
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CAREL INDUSTRIES HeadQuarters
Via dell’Industria, 11 - 35020 Brugine - Padova (Italy)
Tel. (+39) 049.9716611 - Fax (+39) 049.9716600
e-mail: [email protected] - www.carel.com
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