Cairox CVA M Series Installation instructions

p. 1/15 User Instruction CAIROX rev1 –28/01/2022
www.cairox.com
USER INSTRUCTIONS
ELECTRICAL CIRCULAR
DUCT HEATERS
CVA M
CVA MPE
CVA MPX
CVA MPI
CVA MQIA
CVA MQI

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Thank you for your purchase of this product. This manual describes how to use and install the
suppliedproduct.Be surethatyouhavereadandunderstooditscontentsbeforeusingtheheater.
Theelectricalheater'smodelandserialnumber arelocatedonthelabeloftheproduct.
WARNING! SAFETY REQUIREMENTS
Improper use of this heater can result in serious bodily injury due to hazards of fire and
explosion,burnandelectricalshock.
Use only with electrical voltage and frequency specified on model label. Do not perform any
servicewith heater plugged in. Serious injury or death may occur if personnel come in contact
with high voltagelead.
Partsoftheheater becomevery hot when operating andimmediately after operating. Severe
burnsmayoccuriftheheaterisnotallowedtocooldown properlybefore servicing.
TRANSPORTING AND STORING
All products are packed by producer for normal transporting conditions. For unloading and
storinguse proper lifter to prevent product damage and employees injuries. Do not lift product
by power supplycable,connectionbox. Avoidimpactsandimpactloads.
Until final installation store products in dry place with humidity not more 70% (20°C), average
ambient temperature must be 5-40°C. Storing place must be covered from water and dirt. Avoid
longtermstoring.Itis notrecommendedtostoreproductsmorethen1 (one)year.
RECEIVING AND HANDLING
Inspect heater for any possible shipping damage. Inspect heater element wire for any
deformationthatcouldcauseashortcircuitorground.Makesurethat casingof theheateris not
damaged. SERVICE
No special service is required forelectrical heaters, only to check electrical connection not less
than 1time peryear.
QUALITY
We care about quality. 100% of heaters are tested before shipment.
DISPOSAL
Important environmental information about this product.
This symbol on the device or the package indicates that disposal of the device after its lifecycle
couldharmtheenvironment.Do notdisposeof theunitas unsortedmunicipalwaste;itshould be
takentoaspecialized companyfor recycling. Respectthelocalenvironmental rules.
Ifin doubt,contactyourlocalwastedisposalauthorities.

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TABLE OF CONTENTS
Description 4
Installation and electrical connection 5
Dimensions 7
Technical data 8
Model marking 10
Overheating protection 11
Heaters CVA with integrated controller 11
Description of operating CVA MPI …11
Description of operating CVA MPE …11
Description of operating CVA MPX …12
Description of operating CVA MPI …(PTC…PS) 12
Description of operating CVA MPE …(PTC…PS)* 12
Description of operating CVA MPX …(PTC…PS)* 13
Description of operating CVA MPI …2NTC* 13
Description of operating CVA MPE …2NTC* 13
Description of operating CVA MPI …PTC/2NTC* 14
Description of operating CVA MPE …PTC/2NTC* 14
Service 15
Troubleshooting 15
Warranty 15

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DESCRIPTION
Electricalductheaters CVA aredesignedto heatfresh airin ventilation systems. Casing (CVA protection class IP
44, except CVA Type NV which protection class IP 30) is made from Aluzinc coated steel which is high temperature
proof and with rubber seals for duct connection. Tube of heating element is made from stainless steel AISI 304.
Thereare2protectionthermostatsandscrewterminalsforeasyconnectioninstalledin the heaters.
Heaters can be installed horizontally with the electrical connection box facing upwards or sideways and
vertically (only if the air flow direction upwards). Heaters can't be installed in explosive and aggressive substances
environment. Heaters can be used only for the clean air heating or preheating. Heaters intended only for inside
installation. If heater is installed in such way that can be accidental contact with heating elements, protective grill
must be installed. The air velocity in the duct of the heater must be 1,5 m/s minimum. The maximum temperature
oftheoutputis 50°C.
HeatersCVAwithintegratedtemperaturecontrollerEKR-K…(SeeFig.1) canbe controlledin fivedifferentways
dependingoncontroltype:
TypeCVA MPI–potentiometeronthelid ofthe heater(See page 11).
TypeCVA MPE –externalwiredremotesetpointknob(TR5K)fortemperaturecontrol(See page 11).
Type CVA MPX –external wired remote 0…10V signal for temperature control (See page 12).
Type CVA ESKM –external wired remote PWM (ON/OFF: ON(6…24)VDC) signal for temp. control
ElectricalductheatersCVAwithintegratedtemperaturecontrollerEKR-K… worksbyPID regulator.That enable
fine temperature control. Controller EKR-K… controls load by Triacs without moving parts, which causes no-noise
commutation.
Fig. 1
View may vary depending on type EKR-K.

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INSTALLATION AND ELECTRICAL CONNECTION
Electrical duct heaters CVA can be installed horizontally in any position except electrical connection box
downwardandvertically(onlyif theair flow directionupwards)(see Fig. 2).
Fig. 2
We recommend install supply air temperature sensor in distance multiplied by the heater's diameter (3xD).
Forexample:heaterCVAdiameter200mm,sensor'sinstallationdistancewill be:3x200=600mm.
Fig. 3. Mountingexample CVA MPI/NI…
*- TR5K is used in CVA MPE heater version.
**- Temperature set point knob is used in CVA MPI heater version.
Fig. 3
IMPORTANT:
The installation to the mains power supply may only be wired by a competent electrician. The power
supply cable must be selected in the ratio with power of the heater. When installing these heaters, the
standards and regulations in force in your countrymust befollowed strictly adhered to. Within the installation
an electricalisolationautomaticcircuitbreaker(not included)mustbe present, to enablethe installerto cut all
power supply lines. Automatic circuit breaker must be selected regarding power and nominal current (see the
electrical ratingplateon thelidof heater)of theheaterand should have characteristic B. Connectthe heater to
the mains power supply, check thatthe voltage, frequency, powerand current are the same as those indicated
ontheelectricalrating plate.Theheatermustbeearthed.

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Fig. 4. Mounting example CVA MPX/ESKM…
*- External control signal (0…10VDC) is used in CVA MPX type heater.
**- ExternalPWMcontrol signal ON/OFF: ON(6…24VDC) is used in CVAESKM type heater.
Fig. 4
Fig. 5. Mounting example CVA MPI/NI…2NTC…
*- Temperature set point knob and TRNTC10 are used in CVA MPI 2NTC heater version.
**- TR5K NTC10 is used in CVA MPE 2NTC heater version.
Fig. 5
Fig. 6. Mountingexample CVA MPI/NI… (Preheater)
**- TR5K used only in CVA MPE pre-heater version.
*- Temperature set point knob used only in CVA MPI pre-heater
version.
Fig. 6
AHU –Air handling uni

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Fig. 7. Mounting example CVA MPX/ESKM… (Preheater)
*- External control signal 0…10VDC (from AHU if possible) is used in CVA MPX type pre-heater.
**- External PWM control signal ON/OFF: ON 6…24VDC (from AHU if possible) is used in CVA ESKM type
pre-heater.
DIMENSIONS
Fig. 8
Type 1 Type 2 Type 3 Type 4
Type 1 –Standard CVA heater dimensions;
Type 2–CVA heater with external pressure relay dimensions;
Type 3 –CVA heater with external cooling radiator dimensions;
Type4 –CVAheaterwithexternalcoolingradiatorand pressurerelay
diemensions.
Fig. 7
AHU –Air handling unit

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Heater type
A(mm)
B(mm)
C(mm)
D(mm)
CVA 100
370
276
71
100
CVA 125
370
276
71
125
CVA 150
370
276
71
150
CVA 160
370
276
71
160
CVA 200
370
276
71
200
CVA 250
370
276
71
250
CVA 250-12kW
500
402
71
250
CVA 250-15kW
630
532
71
250
CVA 315
373
276
71
315
CVA 315-12kW
500
402
71
315
CVA 315-15kW
630
532
71
315
CVA 315-18kW
630
532
71
315
CVA 355
373
276
71
355
CVA 355-12kW
500
402
71
355
CVA 355-15kW
630
532
71
355
CVA 355-18kW
630
532
71
355
CVA 400
373
276
81
400
CVA 400-12kW
500
402
81
400
CVA 400-15kW
630
532
81
400
CVA 400-18kW
630
532
81
400
CVA 400-21kW
770
672
81
400
CVA 400-24kW
880
782
81
400
CVA 450
373
276
81
450
CVA 500
373
276
81
500
CVA 500-12kW
500
402
81
500
CVA 500-15kW
630
532
81
500
CVA 500-18kW
630
532
81
500
CVA 500-21kW
770
672
81
500
CVA 500-24kW
880
782
81
500
TECHNICAL DATA
CVA
ø(mm)
Min. airflow
(m³/h)
Power supply
(VAC/50Hz)
Power
(kW)
Available
heatng
elements (kW)
CVA 100
100
45
1~230
0,3...1,8
0,3
CVA 125
125
70
1~230
0,3...3,6
0,3/0,6
CVA 150
150
100
1~230
1,2...3,0
0,6/1,0
CVA 160
160
110
1~230
0,3...7,2
0,3/0,6/1,0/1,2
2~400
1,0...6,0
1,0
3~400
3,0...6,0
1,0
CVA 200
200
170
1~230
0,3...7,2
0,3/0,6/1,0/1,2
2~400
1,0...6,0
1,0
3~400
3,0...9,0
1,0/1,5
CVA 250
250
265
1~230
0,3...7,2
0,3/0,6/1,0/1,2
2~400
1,0...9,0
1,0/1,5
3~400
3,0...9,0
1,0/1,5
CVA 250-12kW
250
265
3~400
12,0
1,0/1,5
CVA 250-15kW
250
265
3~400
15,0
1,0/1,5
CVA 315
315
425
1~230
0,6...9,0
0,6/1,0/1,2
2~400
1,0...9,0
1,0/1,5
3~400
3,0...9,0
1,0/1,5

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CVA 315-12kW
315
425
2~400
12
1,0/1,5
3~400
12
1,0/1,5
CVA 315-15kW
315
425
2~400
15
1,0/1,5
3~400
15
1,0/1,5
CVA 315-18kW
315
425
2~400
18
1,0/1,5
3~400
18
1,0/1,5
CVA 355
355
535
1~230
0,6...9,0
0,6/1,0/1,2
2~400
1,0...9,0
1,0/1,5
3~400
3,0...9,0
1,0/1,5
CVA 355-12kW
355
535
2~400
12
1,0/1,5
3~400
12
1,0/1,5
CVA 355-15kW
355
535
2~400
15
1,0/1,5
3~400
15
1,0/1,5
CVA 355-18kW
355
535
2~400
18
1,0/1,5
3~400
18
1,0/1,5
CVA 400
400
680
1~230
0,6...9,0
0,6/1,0/1,2
2~400
1,0...9,0
1,0/1,5
3~400
3,0...9,0
1,0/1,5
CVA 400-12kW
400
680
1~230
9
1,0
2~400
12
1,0/1,5
3~400
12
1,0/1,5
CVA 400-15kW
400
680
1~230
12
1,0
2~400
15
1,0/1,5
3~400
15
1,0/1,5
CVA 400-18kW
400
680
2~400
18
1,0/1,5
3~400
18
1,0/1,5
CVA 400-21kW
400
680
3~400
21
1,0/1,5
CVA 400-24kW
400
680
3~400
24
1,0/1,5
CVA 500
500
1060
1~230
0,6...9,0
0,6/1,0/1,2
2~400
1,0...9,0
1,0/1,5
3~400
3,0...9,0
1,0/1,5
CVA 500-12kW
500
1060
1~230
9
1,0
2~400
12
1,0/1,5
3~400
12
1,0/1,5
CVA 500-15kW
500
1060
1~230
12
1,0
2~400
15
1,0/1,5
3~400
15
1,0/1,5
CVA 500-18kW
500
1060
2~400
18
1,0/1,5
3~400
18
1,0/1,5
CVA 500-21kW
500
1060
3~400
21
1,0/1,5
CVA 500-24kW
500
1060
3~400
24
1,0/1,5
This declaration is in conformity with the requirements of the standards:
LST EN 60335-2-30:2010+AC:2010+A11:2012+AC:2015 (EN60335-2-30:2009+ AC:2010+ A11:2012+ +AC:2014);
LST EN61000-4-2:2009 (EN61000-4-2:2009);
LST EN 61000-4-3:2006+A1:2008+A2:2010 (EN 61000-4-3:2006+A1:2008+A2:2010);
LST EN 61000-4-4:2013 (EN 61000-4-4:2012);
LST EN 61000-4-5:2014 (EN 61000-4-5:2014);
LST EN 61000-4-11:2004 (EN 61000-4-11:2004);
LST EN 61000-6-2:2005 (EN 61000-6-2:2005);
LST EN 61000-3-2:2014 (EN 61000-3-2:2014);
LST EN 61000-6-3:2007 + A1:2011 (EN 61000-6-3:2007 + A1:2011);
LST EN 61000-3-3:2014 (EN 61000-3-3:2013).
and therefore complies with the essential requirements and provisions of the (LVD) 2014/35/EC, (EMC) 2014/30 EC,
(RoHS) 2011/65/EU and REACH.
The CE mark is affixed.

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MODEL MARKING
CVA 100-0.3-1f without integrated control
1 2 3
1 –Duct diameter (mm)
100 –100 mm
160 –160 mm
355 –355 mm
450 –450 mm
125 –125 mm
200 –200 mm
400 –400 mm
500 –500 mm
150 –150 mm
2 –Heating power (kW)
315 –315 mm
450 –450 mm
0.3 –0,3 kW .....24.0 –24,0 kW
3 –Input voltage:
1f –Single phase 230V
2f –2-phase 400V
3f –3-phase 400V
3f –3-phase 230V (on request)
CVA MPI 100-0.3-1f PTC/2NTC with integrated controller
1A 1B 2 3 4
1A –Control type:
NV –Potentiometer for temperature control is on the lid of the heater
NI –External wired remote setpoint knob (TR5K) for temperature control
NIS –External wired remote (0…10) VDC signal for temperature control (analog input)
ESKM –External wired remote PWM (ON/OFF: ON (6…24) VDC) signal for temperature control
1B –Duct diameter (mm)
100 –100 mm
160 –160 mm
355 –355 mm
450 –450 mm
125 –125 mm
200 –200 mm
400 –400 mm
500 –500 mm
150 –150 mm
315 –315 mm
450 –450 mm
2 –Heating power (kW)
0.3 –0,3 kW .....24.0 –24,0 kW (NV, NI, NIS) >15 kW with mounted additional step
0.3 –0,3 kW .....15.0 –15,0 kW (ESKM)
3–Input voltage:
1f –Single phase 230V
2f –2-phase 400V
3f –3-phase 400V
3f –3-phase 230V (on request)
4–Additional accessories:
PS –Differential pressure switch for air flow detection
PTC –Sensor for minimum air velocity detection
PTC/PS –Sensor for minimum air velocity detection and diff. pressure switch for air flow detection
PTC/K –Sensor for minimum air velocity detection and contactor for overheating protection
2NTC –2 sensors for the air temperature measuring
PTC/2NTC –Sensor for min. air velocity detection and 2 sensors for the air temperature measuring

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OVERHEATING PROTECTION
Two overheat protection thermostats are installed in the electrical circular heater CVA. The first one with
automatic reset, turns off the heating when the temperature reaches 50 °C and turns on when the temperature
drops below 50 °C. The second with manual reset, turns off the heating when the temperature reaches 100 °C. In
this case need to figure the cause of the overheating of the heater. Eliminate overheating cause, press „RESET“
buttonon heaterscover.
Additional overheating thermostat (with automatic reset) is installed in the CVA heater with ESKM to protect
the ESKM controller. This thermostat turns off the heating when the temperature reaches 70 °C and turns on when
thetemperaturedropsbelow70°C.
HEATERS CVA WITH INTEGRATED CONTROLLER
Table 1. Technical characteristics ofcontroller EKR-K...
Power supply depending on model single phase 230V / 2 - phase 400V / 3 - phase 400V
Power consumption in standby mode
0,1VA
Ambient temperature
0...50 °C
Relative humidity
Max. 90 % RH (non-condensing)
DESCRIPTION OF OPERATING CVA MPI …
Electrical duct heaters CVA MPI …are designed with integrated temperature control, one temperature sensor,
setpointpotentiometerknob isintegratedontheheaterlid.
When the heater power supply is switched on, LED 6 on the controller (EKR-K…) PCB (see Fig. 1 on page 4)
flashes once every 8 seconds if setpoint is 0 °C and every second if setpoint is higher than 0 °C. If controller turns on
theheatingdependingon thedemand, LED 5lights(see Fig. 1 on page 4).
HeatersCVA MPI…operatesbythesupply(TJ-K10K)airtemperaturesensor.Setpointtemperature(0…30)°C.
There can be set the different desired (setpoint) air temperature by potentiometer on the top of the heater
casing.
DESCRIPTION OF OPERATING CVA MPE …
Electrical duct heaters CVA MPE …are designed with integrated temperature control, one temperature
sensor,wiredremotecontrolpanel(TR5K)fortemperaturesetpoint.
When the heater power supply is switched on, LED 6 on the controller (EKR-K…) PCB (see Fig. 1 on page 4)
flashes once every 8 seconds if setpoint is 0 °C and every second if setpoint is higher than 0 °C. If controller turns on
theheatingdependingon thedemand, LED 5lights(see Fig. 1 on page 4).
HeatersCVA MPE…operatesbythesupply(TJ-K10K)airtemperaturesensor.Setpointtemperature(0…30)°C.
Therecanbesetthedifferentdesired(setpoint)air temperaturebywiredremotecontrolpanel.
If LED 6 lights continuously it means that there is a failure of: supply (TJ-K10K) air temperature sensor or wired
remotecontrolpanelTR5K.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.

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DESCRIPTION OF OPERATING CVA MPX …
Electrical duct heatersCVA MPX …are designed for the heaters power (0…100) % control by analog signal
input(0…10)VDC.
When the heater power supply is switched on, LED 6 on the controller (EKR-K…) PCB (see Fig. 1 on page 4)
flashes every second. If controller turns on the heating depending on analog signal, LED 5 lights (see Fig. 1 on page
4).
DESCRIPTION OF OPERATING CVA MPI … (PTC…PS)
Electrical duct heaters CVA MPI … (PTC…PS) are designed with integrated temperature control, PTC (air
velocity), PS (airpressure)andtemperaturesensors,setpointpotentiometerknobis integratedon theheater lid.
When the heater power supply is switched on, controller (EKR-K…) is in preparation mode for 30 seconds, LED
1 flashes once every 5 seconds. If air velocity is detected by PTC sensor (rapid LED 1 flashes when Min. 1,5 m/s is
detected) and air pressure is greater than min 20kPA after preparation mode ends, LED 1 will start to flash once
every secondand controllerwill initiate the heating based on demand, LED 2 is indicating when heating is initiated.
If there is no air velocity detected and or there is not enough pressure in the duct, controller will not initiate the
heating untilair velocity and or pressureis detected. Heaters CVA MPI…(PTC…PS) operatesby the supply (TJ-K10K)
airtemperaturesensor.
CVA MPI … PTC … setpoint temperature (0…30) °C
CVA MPI…PTC/PSsetpointtemperature(-10…50)°C
There can be set the different desired (setpoint) air temperature by potentiometer on the top of the heater
casing.
Pre-heatercasingandairductbeforepre-heatershouldbeinsulated with rock wool10cm (R~2,4m²K/W).
Depending on the mounting position of the heater in the duct relative to the motor (pre- or post-motor), the
pressurehose mustbe placedon the"-"or "+" pipe,respectively.
DESCRIPTION OF OPERATING CVA MPE … (PTC…PS)*
Electricalduct heatersCVA MPE …(PTC…PS)are designed with integrated temperature control, PTC (air
velocity)PS(airpressure)andtemperaturesensors,wiredremotecontrolpanel(TR5K) fortemperaturesetpoint.
When the heater power supply is switched on, controller (EKR-K…) is in preparation mode for 30 seconds, LED
1 flashes once every 5 seconds. If air velocity is detected by PTC sensor (rapid LED 1 flashes when Min. 1,5 m/s is
detected) and air pressure is greater than min 20kPA after preparation mode ends, LED 1 will start to flash once
every secondand controllerwill initiate the heating based on demand, LED 2 is indicating when heating is initiated.
If there is no air velocity detected and or there is not enough pressure in the duct, controller will not initiate the
heatinguntilairvelocityand orpressureis detected.
HeatersCVA MPE…(PTC…PS)operatesbythesupply(TJ-K10K)airtemperature
sensor.CVA NI … PTC … setpoint temperature (0…30)
°C CVA MPE…PTC/PSsetpointtemperature(-10…50)°C
Therecanbesetthedifferentdesired(setpoint)airtemperaturebywiredremotecontrolpanel.
Pre-heatercasingandairductbeforepre-heatershouldbeinsulated with rock wool10cm (R~2,4m²K/W).
Depending on the mounting position of the heater in the duct relative to the motor (pre- or post-motor), the
pressurehose mustbe placedon the"-"or "+" pipe,respectively.
*- nonstandardoption.Formoreinformationpleasecontactus : www.cairox.com
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.

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DESCRIPTION OF OPERATING CVA MPX … (PTC…PS) *
Electrical duct heaters CVA MPX …(PTC…PS) are designed for the heaters power (0…100) % control by
analogsignalinput(0…10)VDC,withintegratedPTC(airvelocity)and PS(airpressure)sensors.
When the heater power supply is switched on, controller (EKR-K…) is in preparation mode for 30 seconds, LED
1 flashes once every 5 seconds. If air velocity is detected by PTC sensor (rapid LED 1 flashes when Min. 1,5 m/s is
detected) and air pressure is greater than min 20kPA after preparation mode ends, LED 1 will start to flash once
every secondand controllerwill initiate the heating based on demand, LED 2 is indicating when heating is initiated.
If there is no air velocity detected and or there is not enough pressure in the duct, controller will not initiate the
heatinguntilairvelocityand orpressureis detected.
Pre-heatercasingandairductbeforepre-heatershouldbeinsulated with rock wool10cm (R~2,4m²K/W).
Depending on the mounting position of the heater in the duct relative to the motor (pre- or post-motor), the
pressurehose mustbe placedon the"-"or "+" pipe,respectively.
* -nonstandardoption.Formoreinformationpleasecontactus : www.cairox.com
DESCRIPTION OF OPERATING CVA MPI … 2NTC*
Electrical duct heaters CVA MPI …2NTC are designed with integrated temperature control, two
temperaturesensors,potentiometeronthetop oftheheatercasing fortemperaturesetpoint.
When the heater power supply is switched on, LED 6 on the controller (EKR-K…) PCB (see Fig. 1 on page 4)
flashes depending on theoperating mode. If controller turns on the heating depending on the demand, LED 5 lights
(see Fig. 1 on page 4).
HeatersCVA MPE…2NTCcanoperatein twomodes:
1. Control by the supply air temperature sensor (TJ-K10K), when the first (1) switch of JP1 -(R37) (see Fig. 1 on
page 4) isinpositionON.LED 6flashestwicepersecond.Setpoint temperature(0…30)°C.
2. Control by the supply (TJ-K10K) and by the room (NTC10) air temperature sensor, when the first (1) switch of
JP1- (R37)(see Fig. 1 on page 4) is inposition OFF. LED 6 flashes onceper second. Setpoint temperature(15…30) °C.
Inthismodeispreprogrammedtheminimum (15°C) and themaximum (45°C) temperatures of supply air. The room
airtemperaturesensorismountedin thewiredremotecontrolpanelTR5KNTC10.
Depending on the operating mode there can be set the different desired (setpoint) air temperature by wired
remotecontrolpanelTR5KNTC10.
* -nonstandartoption.Foremoreinformationpleasecontactus : www.cairox.com
DESCRIPTION OF OPERATING CVA MPE … 2NTC*
Electrical duct heaters CVA MPE … 2NTC are designed with integrated temperature control, two temperature
sensors,wiredremotecontrolpanel(TR5KNTC10)fortemperaturesetpoint.
When the heater power supply is switched on, LED 6 on the controller (EKR-K…) PCB (see Fig. 1 on page 4)
flashes depending on the operating mode. If controller turns on the heating depending on the demand, LED 5 lights
(see Fig. 1 onpage 4).
HeatersCVA MPE…2NTCcanoperatein twomodes:
1. Control by the supply air temperature sensor (TJ-K10K), when the first (1) switch of JP1 -(R37) (see Fig. 1 on
page 4) isinpositionON.LED 6flashestwicepersecond.Setpoint temperature(0…30)°C.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.

p. 14/15 User Instruction CAIROX rev1 –28/01/2022
2. Control by the supply (TJ-K10K) and by the room (NTC10) air temperature sensor, when the first (1) switch of
JP1 -(R37) (see Fig. 1 on page 4) is in position OFF. LED 6 flashes once per second. Setpoint temperature (15…30) °C.
Inthismodeispreprogrammed theminimum (15°C) and themaximum (45°C) temperatures of supply air. The room
airtemperaturesensorismountedin thewiredremotecontrolpanelTR5KNTC10.
Depending on the operating mode there can be set the different desired (setpoint) air temperature by wired
remotecontrolpanelTR5KNTC10.
* -nonstandartoption.Foremoreinformationpleasecontactus : www.cairox.com
DESCRIPTION OF OPERATING CVA MPI … PTC/2NTC*
Electrical duct heaters CVA MPI … PTC/2NTC are designed with integrated temperature control, PTC (air
velocity) andtwotemperaturesensors,potentiometeron thetopoftheheatercasing fortemperaturesetpoint.
When the heater power supply is switched on, controller (EKR-K) is in preparation mode for 30 seconds, LED 1
flashes once every 5 seconds. If air velocity is detected by PTC sensor (rapid LED 1 flashes when Min. 1,5 m/s is
detected) after preparation mode ends, LED 1 will start to flash once every second and controller will initiate the
heating basedon demand, LED 2 is indicating when heating is initiated. Ifthere is no air velocity detected, controller
willnotinitiatetheheatinguntilair velocitydetected.
HeatersCVA MPI…PTC/2NTCcanoperatein twomodes:
1. Control by the supply air temperature sensor (TJ-K10K), when the first (1) switch of JP1 -(R37) (see Fig. 1 on
page 4) isinpositionOFF.LED1flashesoncepersecond.Setpointtemperature(0…30)°C.
2.Control by the supply (TJ-K10K) and by the room (NTC10) air temperature sensor, when the first (1) switch of
JP1-(R37)(see Fig. 1 on page 4) is in position ON. LED 1 flashes twice per second. Setpoint temperature (15…30)°C.
Inthismodeispreprogrammedtheminimum (15°C) and themaximum (40°C) temperatures of supply air. The room
airtemperaturesensoris mountedin the wiredpanelTRNTC10.
Depending on the operating mode there can be set the different desired (setpoint) air temperature by
potentiometeron thetopofthe heatercasing.
* -nonstandartoption.Foremoreinformationpleasecontactus : www.cairox.com
DESCRIPTION OF OPERATING CVA MPE … PTC/2NTC*
ElectricalductheatersCVA MPE…PTC/2NTC are designed with integrated temperature control, PTC (air
velocity)andtwotemperaturesensors,wiredremotecontrolpanel(TR5KNTC10)fortemperaturesetpoint.
When the heater power supply is switched on, controller (EKR-K…) is in preparation mode for 30 seconds, LED
1 flashes once every 5 seconds. If air velocity is detected by PTC sensor (rapid LED 1 flashes when Min. 1,5 m/s is
detected) after preparation mode ends, LED 1 will start to flash once every second and controller will initiate the
heating basedon demand, LED 2 is indicating when heating is initiated. Ifthere is no air velocity detected, controller
willnotinitiatetheheatinguntilair velocitydetected.
HeatersCVA MPE…PTC/2NTCcanoperateintwo modes:
1. Control by the supply air temperature sensor (TJ-K10K), when the first (1) switch of JP1 -(R37) (see Fig. 1 on
page 4) isinpositionOFF.LED1flashesoncepersecond.Setpointtemperature(0…30) °C.
2.Control by the supply (TJ-K10K) and by the room (NTC10) air temperature sensor, when the first (1) switch of
JP1 -(R37)(see Fig. 1 on page 4) is in position ON. LED 1flashes twice per second. Setpoint temperature (15…30)°C.
Inthismodeispreprogrammedtheminimum (15°C) and themaximum (40°C) temperatures of supply air. The room
airtemperaturesensorismountedin thewiredremotecontrolpanelTR5KNTC10.
Depending on the operating mode there can be set the different desired (setpoint) air temperature by wired
remotecontrolpanelTR5KNTC10.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.

p. 15/15 User Instruction CAIROX rev1 –28/01/2022
* - non standart option. Fore more information please contact us : www.cairox.com
SERVICE
No specialserviceis required for electrical heaters, only to check electrical connection not less than 1 time per
year.
TROUBLESHOOTING
No heating from
heater
1. If the manual protection is activated, check for a fault before pressing the RESET
button. If the fault is identified after it has been rectified, press the RESET button
using a screwdriver or similar object.
2. No power supply to heater –check all external electrical connection components
(relays, switches).
3. Temperature sensor fault. Check sensor resistance, it must be 10kΩ at 25°C.
4. Pressure switch fault. Check if pressure in system is set correctly (check the
pressure when air flow is not less than 1,5m/s).
5. If LED 1 lights continuously it means that there is a failure of: PTC (air velocity)
sensor, supply (TJ-K10K) or room (NTC10) air temperature sensor, potentiometer on
the top of the heater casing, wired remote control panel TR5K.
6. When the heater power supply is switched on, after power supply interruption or
after any failure, controller is in preparing mode for 30 seconds.
7. PCB fault. Contact: qualit[email protected]
Heater gives full
output, not by set
point
1. Temperature sensor fault. Check sensor resistance, it must be 10kΩ at 25°C.
2. Air flow sensor fault. Check sensor resistance. It must be 22Ω between X15…X16
and 10Ω between X15...X18. Sensor must be clear.
3. When the heater power supply is switched on, after power supply interruption or
after any failure, controller is in preparing mode for 30 seconds.
4. Triacs fault. Contact: [e-mail]
5. PCB fault. Contact: qualit[email protected]
Automatic circuit
breaker switching off
1. Check circuit breakers data, it must correspond to heaters electrical data.
2. Check isolation of connection cables, wires, check is heater grounded.
3. Check power supply source data, it must correspond to heaters electrical data.
Protection thermostat
cut off
1. Low air flow speed through heater. Check filters, fans, ducts of system.
2. Pressure switch fault. Check if pressure in system is set correctly (check the
pressure when air flow is not less than 1,5m/s).
WARRANTY
1. Manufacturer declares 2 years warranty term from the date of manufacturer's invoice. Warranty is applied
incaseif allrequirementsof transporting,storing,installationand electricalconnectionare fulfilled.
2. In case of damaged or faulty product during warranty term customer must inform producer in 5 days and
deliverproducttomanufactureassoonaspossibleatcustomer'scosts.Inothercase warrantyis notvalid.
3. Manufacturerisnotresponsiblefordamageswhichoccurduringtransportationorinstallation.
IMPORTANT: If failure appears, power supply must be switched off and only then performed fault
elimination works.