Ventair CU24V1 Technical manual

Operation instruction
Controller for air handling units CU24V1

2
Software version from 6.2
Contact:
VentiAir s.r.o.
Adolfovice 512
790 01 Bělá pod Pradědem
CZ –Czech Republic
IČ: 06935320 DIČ: CZ06935320
Email: [email protected]om; [e-mail]
Phone: [phone]
The device is manufactured in accordance with the European standard EN1886, EN13053
This documentation must always be handed over to the customer!
In case of non-compliance with the conditions stated in this documentation, VentiAir s.r.o.
reserves the right to refuse the warranty.
Version 02/2021

3
1CONTENTS
1 Contents ...........................................................................................................................................3
2 Controller .........................................................................................................................................5
2.1 Application ...............................................................................................................................5
2.2 Functions..................................................................................................................................5
2.3 Basic parameters......................................................................................................................6
2.4 Standard controller inputs and outputs...................................................................................6
3 Wiring diagram of the controller......................................................................................................8
4 Controller parameters......................................................................................................................9
4.1 Unit equipment ........................................................................................................................9
4.1.1 Selecting the type of heating and cooling....................................................................... 9
4.1.2 Control type................................................................................................................... 10
4.1.3 Recovery type................................................................................................................ 10
4.1.4 Type of fan..................................................................................................................... 10
4.1.5 Heat pump control ........................................................................................................ 10
4.2 Parameter values....................................................................................................................11
4.2.1 Supply air parameters ................................................................................................... 11
4.2.2 Heating parameters....................................................................................................... 11
4.2.3 Cooling parameters....................................................................................................... 12
4.2.4 Heating –cooling hysteresis.......................................................................................... 13
4.2.5 Pre-heating (if included)................................................................................................ 13
4.2.6 Compressor ................................................................................................................... 13
4.2.7 Heat exchanger parameters.......................................................................................... 14
4.2.8 Exchanger defrost.......................................................................................................... 14
4.2.9 Recirculation dampers control (mixing chamber)......................................................... 15
4.2.10 By-pass and earth exchanger settings (not a standard)................................................ 15
4.2.11 Fan parameters ............................................................................................................. 15
4.2.12 CO2 control..................................................................................................................... 16
4.2.13 Programming the fan gears........................................................................................... 16
4.2.14 Pump parameters.......................................................................................................... 16
4.2.15 User Functions E4, E5.................................................................................................... 16
5 Ethernet..........................................................................................................................................18
5.1 sample interface pages: .........................................................................................................18
5.2 Connection .............................................................................................................................18
5.3 LED description......................................................................................................................18
5.4 Converter connection.............................................................................................................19
5.5 Converter settings..................................................................................................................19

4
6 MODBUS.........................................................................................................................................20
6.1 CU24V controller - LIST OF REGISTERS WITH ADDRESS (Function 03, 06).............................20
6.1.1 Setting the slave address of the controller ................................................................... 20
6.1.2 List of adress.................................................................................................................. 20
6.2 Operating state register description ......................................................................................22
6.2.1 Register 1....................................................................................................................... 22
6.2.2 Register 2....................................................................................................................... 22
6.3 Alarm register description R1H, R1L ......................................................................................23
6.3.1 RH - Register 1 (Most significant/high register)............................................................ 23
6.3.2 RL - Register 2 (Least significant/low register).............................................................. 23
6.4 Input registers: function 04....................................................................................................23
6.5 Coils (Digital Outputs): function 01........................................................................................23
6.6 Discret inputs (Digital inputs): function 02 ............................................................................24

5
2CONTROLLER
2.1 APPLICATION
The controller is dedicated for inlet-outlet AHU with exchanger or without. The controller is delivered
with a remote panel RMC20 with built-in graphic display.
2.2 FUNCTIONS
Temperature control
-Cascade control with min/max limit on supply air
-Supply air temperature control
-Water and electric heating control
-Water cooling and compressor control
-Preliminary heating function
-Water heater frost protection
-High temperature protection of electric heaters
Fans control
-Inlet and outlet fan control
-Inverter control
-Engine alarm
Heat recovery control
-Exchanger control
-Exchanger frost protection
-Exchanger protection by bypass damper or inlet fan speed modulation
Real time clock with week schedule
Alarms
-Alarms information’s on the RMC20 panel
-Alarm clearing from the panel
BMS
-BMS facilities by RS485 serial communication
-MODBUS Communication protocol

6
2.3 BASIC PARAMETERS
Type
Nr
Characteristic
Inputs
Resistive
4
PT1000 type, range -25 …+70 °C
Analog
1
0-10V
Digital
5
Free potential contact
Outputs
Analog
6
0-10V / 2mA
Modulated
2
21V ±2VDC / 50mA
Relay
5
250VAC, 3A / Resistive load
Communication
RS485 serial port: 2 ports
Distance: up to 50m
Communication protocol MODBUS
2.4 STANDARD CONTROLLER INPUTS AND OUTPUTS
G0, G
Power supply: 24 VAC ± 10%, 50/60 Hz, input: 6VA (outputs P1, P2 unloaded)
M
System ground voltage
B1-B4
Resistance inputs PT1000
E1-E5
Potential-free resistance inputs
X1
Analog input 0-10V
Q1 - Q4
Relay output –normally open
DA
Relay output –24 V
U1-U2
Relay output –230 V
Y1-Y6
Voltage outputs 0-10 V DC
P1, P2
24 V DC modulated outputs; for continuous regulation of electric heaters. Controlled
devices should be connected between P1 (+) and ground M (-), or P2 (+) and ground M (-)
A1, B1
Serial interface RS485 Nr. 1
A2, B2
Serial interface RS485 Nr. 2
Digital outputs
When the
system works
properly
In an alarm
condition
E1
Water heater frost protection thermostat
closed
Freeze alarm
Electric heater alarm
closed
Hi temperature
E2
Inlet and outlet filter pressure switch
open
E3
Confirmation of supply fan operation, confirmation of
exhaust fan operation, confirmation of rotary
recuperator operation, supply fan pressure switch
closed
Engine alarm
E4
Cooling source alarm
open
Cooling source
alarm
E5
Enable operation / Service switch
open
Disable operation
PP
EPS signal
closed
Disable operation

7
Analog inputs (0-10VDC signal inputs)
X1
Sensor CO2(optional)
Temperature sensor PT1000
B1
Exhaust
B2
Supply
B3
Exhaust behind the recuperator
B4
Outdoor
Digital outputs
U1/U2
Heating water pump
Relay (230VAC)
Electric heater
Relay (230VAC)
DA
Inlet/outlet flap
Relay (24VAC)
Q1
Supply fan
Relay
Q2
Exhaust fan
Relay
Q3
Cooling water pump / Cooling water source operation signal
Relay
1st cooling source / Condensing unit operation signal
Relay
Q4
2st cooling source / Heating/cooling signal for condensing unit
Relay
Analog outputs (0-10VDC, PWM signal outputs)
Y1
Supply fan control
Y2
Exhaust fan control
Y3
Heater (water or electric) / Heat pump
Y4
Water cooler
Y5
Heat / cold recovery (plate / rotary recuperator)
Y6
Mixing flap (10-0V), inlet / outlet flap (0-10V)

8
3WIRING DIAGRAM OF THE CONTROLLER

9
4CONTROLLER PARAMETERS
4.1 UNIT EQUIPMENT
Setting a program to the CU24V1 controller is done remotely using the RMC20 panel. Before setting a
program, the unit should be switch off (In the display the message "UNIT IS OFF" should be displayed).
You can choose from a ready-made application or user application that allows you to manually
configure the application by editing individual options.
Name
Default value
Options
Descriptions
AP
USER
USER
User application:
Manual adjustments by users
W-001 ÷ E-012
Application for supply-extraction units
4.1.1 SELECTING THE TYPE OF HEATING AND COOLING
Beware:
The bellow settings are valid when the heat pump mode at page #11 of the menu is off, it means the
following setting is done: Heat pump: No
Heating:
•water: Water coil heater with control signal at Y3 output
•electr: Electric heater with control signal at PWM output P2
•none: No heater
Outputs Y3 and P2 of the CU24V1 controller work independently of the type of heater, while the E1
input, depending on the type of heater, functions as an anti-freeze alarm or a high temperature alarm..
Heating
CU24V1 outputs
CU24V1 input
Y3
P2
U1-U2
E1
water
0-10V:
heating
control
PWM output
for electric
heater
230 VAC: Pump start.
Frost alarm of water
heating coil
electr
0-10V:
heating
control
PWM output
for electric
heater
230 VAC: Enable working for
electric heaters.
Hi temperature alarm
of electric heater
Cooler:
•Water: Water coil cooling with smooth control in PI integration mode.
•agregat-1: Single stage cooling unit with ON/OFF control
•agregat-2: Two-stage cooling unit with control outputs at Q3 and Q4 in PI integration
mode
•None: No cooler
The Y4 output of the CU24V1 is active regardless of the type of cooling (water, chiller-1, or chiller-2)
and can be used to control the valve or chiller. On the other hand, the output Q3 is used to control the
pump or the first stage of the chiller depending on the selection, and Q4 confirms the cooling mode or
controls the second stage of the chiller.

10
Below the table illustrating the possible situation.
Cooler
CU24V1 outputs
Y4
Q3
Q4
water
(PI control)
0-10V: valve or chiller
control
Pump or chiller start
Signalling of operating mode
- closed: cooling mode
- open: heating mode
agregat-1
(ON/OFF
contr.)
0-10V: valve or chiller
control
Chiller start
Signalling of operating mode
- closed: cooling mode
- open: heating mode
agregat-2
(PI control)
0-10V: valve or chiller
control
Chiller start –first stage
Chiller start –second stage
4.1.2 CONTROL TYPE
•Cascade: Cascade control with main sensor at B1 input and limit sensor at B2 input
•Supply: Supply air temperature control with supply sensor at B2 input.
4.1.3 RECOVERY TYPE
•BY-PASS: Plate heat exchanger with by-pass or rotary heat exchanger with 0-10V control at Y5
output of the CU24V1 controller
•PLATE: Plate heat exchanger without by-pass with inlet fan speed control
•DAMPER: Recirculation (mixing chamber) with 0-10V control at Y6 output of the controller
•EXC+DAMPER: Plate heat exchanger with by-pass or rotary heat exchanger + recirculation
(mixing chamber). 0-10V control outputs of the CU24V1 controller are respectively Y5 for the
exchanger and Y6 for the mixing chamber.
Type of exchanger protection
•B3: Temperature sensor at input B3
•E5: Presostat control at input E5.
4.1.4 TYPE OF FAN
Select between inverter control or 1-2 gear AC fan control.
4.1.5 HEAT PUMP CONTROL
For systems with a heat pump where the device performs winter heating and summer cooling, it is
possible to program the controller to control these systems. Set the heat pump mode by setting the
following parameters:
- Heat pump: Yes
- Heating: water
- Cooling: water
After this setting, signal Y3 controls the heating or cooling power from 0 to 10V, while for some units
with other control logic, signal Y4 controls the heating power from 5 to 10V and the cooling power
from 5V to 0V. Output Q3 works as the start of the unit while Q4 determines the heating or cooling
mode.

11
Below is a description of the outputs in the table.
Operating
mode
Outputs CU24V1
Y3
Y4
Q3
Q4
Heating
0-10V:
Heating control
5-10V:
Heating control
Unit start
Operating mode select
Open: heating
Cooling
0-10V:
Cooling control
5-0V:
Cooling control
Unit start
Operating mode select
Closed: cooling
4.2 PARAMETER VALUES
4.2.1 SUPPLY AIR PARAMETERS
Name
Default value
Range
Description
MIN
15C
0 ÷
66C
Minimum temperature of air supply
MAX
35C
5 ÷
70C
Maximum temperature of air supply
4.2.2 HEATING PARAMETERS
Name
Default value
Range
Description
PBAND
30.0°C
0 ÷ 999.9°C
Proportional band.
Setting PBAND = 0 means ON / OFF
operation with hysteresis and the
entered HYS parameter.
INT
100 sec
0 ÷ 6000 sec
Integral time
HYS
1.5°C
0.5 ÷ 10.0°C
Hysteresis for two-position control.
If the PBAND = 0, hysteresis determines
the HYS parameter
Operation ON/OFF
HDIS
18oC
10 ± 22oC
Outside temperature above which the
heating is turned off (the SUMMER mode)
PREHEAT
(preheating -
only water
heating)
ON
ON, OFF
Preliminary heating:
Before the fans start the heater is warm
up.
FOVER
MAN
AUTO, MAN
Frost alarm clearing:
MAN –Manual start of the unit after
clearing alarm manually.
AUTO –Automatic alarm reset and unit
start after the alarm signal disappears.
HDIS parameter operation scheme

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4.2.3 COOLING PARAMETERS
Name
Default value
Range
Description
PBAND
30.0°C
0 ÷ 999.9°C
Proportional band.
Setting PBAND = 0 means ON / OFF
operation with hysteresis and the entered
HYS parameter.
INT
100 sec
0 ÷ 6000 sec
Integral time
HYS
1.5°C
0.5 ÷ 10.0°C
Hysteresis for two-position control.
If the PBAND = 0, hysteresis determines
the HYS parameter
Operation ON/OFF
CDIS
15oC
10 ± 22oC
Outside temperature below which the
cooling is turned off (the WINTER mode).
CDIS parameter operation scheme
Outdoor temperatureCDIS CDIS+1
Cooling disabled Hysteresis
Enable coolingDisable cooling
Outdoor temperatureHDIS-1 HDIS
Heating enabled Hysteresis
Disable heatingEnable heating

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4.2.4 HEATING –COOLING HYSTERESIS
Switching from heating to cooling takes place after the heating is switched off and the temperature
rises by HYS1 above the set temperature. Switching from cooling mode to heating mode takes place
after cooling is switched off and the temperature drops by HYS1 below the set temperature.
Name
Default value
Range
Description
HYS1
2.0°C
0.5 ÷ 9.9°C
Dead zone between heating and cooling.
4.2.5 PRE-HEATING (IF INCLUDED)
The pre-heater is installed before the heat exchanger. The temperature is measured by a sensor
located at the outlet of the heat exchanger. The set temperature is marked "T set". "T measured"
indicates the current temperature on the heat exchanger.
Name
Default value
Range
Description
t set
8,0oC
-10 ± 30oC
Required temperature for preheater
4.2.6 COMPRESSOR
Name
Default value
Range
Description
CPOFF
180 sec
30 ÷ 300
sec
Compressor shutdown time:
Minimum time between switching the
compressor off and on again.
CPON
30 sec
5 ÷ 100 sec
Inactive alert time:
Time during which the low pressure switch is
inactive after starting the compressor
Heater
Cooler
Set temperature –HYS1
Set temperature + HYS1
Set temperature

14
4.2.7 HEAT EXCHANGER PARAMETERS
The ELIM parameter specifies the minimum allowed temperature on the heat exchanger outlet. When
the temperature is below this threshold, the heat exchanger alarm is switched on, the air supply fan is
switched off and the system starts the heat exchanger defrosting cycle.
Name
Default
value
Range
Description
ELIM
5C
-10 ÷ +10C
Alarm temperature for the heat exchanger
4.2.8 EXCHANGER DEFROST
Defrosting the exchanger is done by running the extract fan at the highest speed for a period of two to
five minutes (depending on the outside temperature), while the inlet fan is stopped. After the defrost
time has elapsed, the extract fan returns to the programmed speed for 20 minutes and the inlet fan
remains off unless the frost alarm goes off.
If after 20 minutes the heat exchanger temperature is still lower than the alarm level, the defrost
procedure will be restarted.
The defrosting procedure ends when the temperature at the exchanger outlet rises above the alarm
level.
The curve representing the defrost time as a function of the outdoor temperature:
Outdoor temperature
Defrost time
-10C
5 min
-5C
2 min

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4.2.9 RECIRCULATION DAMPERS CONTROL (MIXING CHAMBER)
After setting the type of recovery (MENU page #10), you can define at page #23 the damper control by
setting the parameter DAMP:
•Auto –damper control as a function of outdoor temperature according to the curve defined at
MENU pages #24 and #25
•OFF, 10%, 20%, .... 100% - manual control of the dampers
Name
Default value
Range
Description
DAMP
OFF
OFF,
10%,20%,…100%,
AUTO
Type of damper control
ODT1
0 C
-25 ÷ 30C
Outdoor temperature low range value.
ODT2
0 C
-25 ÷ 30C
Outdoor temperature high range value.
DACO1
0 %
0 ÷ 100 %
Damper control low range value
DACO2
0 %
0 ÷ 100 %
Damper control high range value
4.2.10 BY-PASS AND EARTH EXCHANGER SETTINGS (NOT A STANDARD)
•AUTO: Bypass is controlled depending on the outdoor and the outlet/indoor temperatures.
•ON: Switch on Bypass
•OFF: Switch off Bypass
4.2.11 FAN PARAMETERS
•FCOEF: Programming separate speeds of the air supply and air exhaust fans
It is possible to set separate speeds for both air supply and air exhaust fans. The FCOEF
parameter defines the dependency between the fan speeds according to the following
formula:
Air exhaust fan speed = air supply fan speed x FCOEF
•START: Delayed start - After the system switched on, the shut-off dampers open, the fans start
only after the set interval has elapsed.
•STOP: Delayed stop - After the system switched off, all devices will switch off while the fans
continue to run for the time specified by the STOP parameter. For air handling units with
electric heaters, it is necessary to set a delayed switch-off of the fans always to ensure
sufficient cooling of the heater.
•FMOD: This mode disables / enables the supply fan safety modulation function. The FMOD
parameter determines the temperature behind the heat recovery heat exchanger on the
extract air duct. If the FMOD parameter is OFF, the supply fan is not modulated in this mode.
If the extract air temperature behind the recuperator falls below the FMOD value, the system
reduces the supply fan speed as required up to the value given by the FMIN parameter.
•FMIN: Minimum fan speed on the supply air duct. The speed of the supply fan is modulated in
order to protect the heat exchanger against freezing. The FMIN parameter determines the
minimum speed of the supply fan during modulation.

16
Name
Default value
Range
Description
FCOEF
1.00
0,5 ± 2
Exhaust/supply ratio:
Exhaust fan speed ratio to supply fan.
Exhaust = FCOEF x Supply
FMIN
10%
10 ± 25%
Fan minimum speed:
The speed below which the fan cannot go
down during speed modulation
FMOD
7oC
-10 ± 10oC
Fan modulation start:
Defines when the supply fan starts
modulating to protect the exchanger. This
is the number of degree C above the
exchanger protection value ELIM.
START
0 sec
0 ÷ 100 sec
Start delay
STOP
0 or 30 sec
(according to the
heating type)
0 ± 100 sec
Stop delay (for units with el. Heating min.
30s)
4.2.12 CO2CONTROL
The CU24V1 controller has the ability to control CO2. The CO2 control is performed
automatically after the CO2 detector has been detected in the X1 input of CU24V1. CO2
regulation is achieved either by adjusting the fan speed or by adjusting the dampers. If the
damper parameter is set DAMP = AUTO, the damper is adjusted. If DAMP has a value other
than AUTO then the regulation is controlled by fan speed.
4.2.13 PROGRAMMING THE FAN GEARS
Name
Default value
Range
Description
SPD1
25%
10 ± 100%
Fan speed for gear 1
SPD2
50%
10 ± 100%
Fan speed for gear 2
SPD3
75%
10 ± 100%
Fan speed for gear 3
SPD4
100%
10 ± 100%
Fan speed for gear 4
4.2.14 PUMP PARAMETERS
Name
Default value
Range
Description
PUMPON
0oC
-25 ± 15oC
Outdoor temperature below witch the
heater pump is switched on
4.2.15 USER FUNCTIONS E4, E5
With the ERC20 control unit, specific operation functions can be configured at input E4. If the input is
used, then you can use the RMC20 panel to select one of the following functions, which will be
performed by the control after the signal is started at the E4 input.

17
Mode
Function
OFF
The user is denied access, at input E4 is no signal
1
The supply fan is at maximum speed
The exhaust fan is at maximum speed
2
The supply fan runs at first speed
The exhaust fan is at maximum speed
3
The supply fan is off
The exhaust fan is at maximum speed
4
The supply fan is at minimum speed
The exhaust fan is at minimum speed
5
The supply fan is at maximum speed
The exhaust fan runs at first speed
6
The supply fan is at maximum speed
The exhaust fan is off
For example, a humidity sensor or any other device that will perform the required function can be
connected to input E4. An example of use can be a button on the toilet as well.
Input E5 is used for EPS signal, closed contact allows unit operation.

18
5ETHERNET
uManager 10 is a converter with built-in http server, which enables remote management of air
handling units controlled by Uni Control System controllers by mean of a smartphone, tablet or
computer. Communication with the is done via a website with a graphic interface, so you can manage
the unit from anywhere in the world if the network is available. You can connect from iOS and Android
or Windows devices. The smart interface recognizes the type of terminal and adapts automatically to
it. The site works under various Internet browsers like Firefox, Chrome, Safari etc ....
5.1 SAMPLE INTERFACE PAGES:
5.2 CONNECTION
Connect the converter from one side to the controller through the RS485 serial port (terminals A, B)
and on the other hand to the Internet socket.
A 24VAC supply must be connected to the G0, G terminals
Descriptions of symbols:
•G0, G: 24 VAC power supply
•A,B: RS485 serial port
5.3 LED DESCRIPTION
•POWER: Power supply signalling
•Modbus: Modbus communication signalling Lights up when the transmission starts on
Modbus. Goes off at the end of broadcasting
•100Mbps: LED lights up when the physical layer negotiates 100 MBps transfer rate. Goes off
when the cable is disconnected
•ETH_Link: The LED lights up when the application has received the packet and is lit for 200
ms
•RESET: Device reset
•FACT RESET: Restore factory settings

19
B A G
POWER
ETH_Link
Modbus RESET
G0
FACT
RESET
100Mbps
5.4 CONVERTER CONNECTION
Enter the IP address of the device, the default values are:
•IP: 192.168.0.50
•Address mask IP: 255.255.255.0
•TCP Port: 80
•Modbus: ASCII, 9600 baud, 8 bit data, 1 bit stop, No parity, address 1, delay 30
5.5 CONVERTER SETTINGS
After entering the converter's IP address, the login screen should appear in the browser. Enter your
login and password there and click "Login". The default account is:
•Login: admin
•Password: admin
After logging in, select the option Detail at the bottom right of the screen.
In the subpage Ethernet Configuration, you must replace the factory IP with your own and set the
network settings.
In the subpage Modbus Configuration, the communication parameters of the converter with the
UCS controller must be set. The communication parameters must be identical to those set on the
UCS controller.
For the ERC20 and CU24V1 controllers, you can find the communication parameters in the RMC20
panel menu.
For UCS controllers, the parameters can be found in the controller menu.
After entering new data, the converter is reset automatically and you must enter the new IP into the
browser to connect to the converter.

20
6MODBUS
6.1 CU24V CONTROLLER -LIST OF REGISTERS WITH ADDRESS (FUNCTION 03, 06)
•Protocol: MODBUS RTU (See information on the RMC20 display)
•Baud rate: 9600
•Bit number: 8
•Parity: No
•Stop bit: 1
•Slave address: 1
6.1.1 SETTING THE SLAVE ADDRESS OF THE CONTROLLER
6.1.2 LIST OF ADRESS
Warning:
MODBUS address is the address that is specified directly in the MODBUS protocol frame,
Registers in the controller have double Modbus address. The second address is for use in the range
from 0 to 9999 because not all software are able to use address above 9999. To have access to the
second address just subtract the value 55536 from the address listed in the tables.
Items in red colour are not available.
Register Name
Register
MODBUS
Address
PWM outputs P
NOTE:
1. Control values are in w % with 1/10
precision. After reading the register value the
dot should be placed artificially Ex.: Reading
the value 257 should be treated as 25.7%
2. The value 0x8000 means, the parameter is
not available.
0 –P1
1 - P2
…
n - Pn
65472
65473
...
65472+n
0-10V analog outputs
NOTE:
1. Control values are in w % with 1/10
precision. After reading the register value the
0 –Y1
1 –Y2
…
n –Yn
65408
65409
S1
S2
Address
1
2
3
4
1
2
3
4
□
□
□
□
□
□
□
□
1
■
□
□
□
□
□
□
□
2
□
■
□
□
□
□
□
□
3
■
■
□
□
□
□
□
□
4
■
■
■
■
■
■
■
□
255