Instruction Manual HBDF MK2 Defrost Sensor For automatic defrosting of evaporators Simple Setup, only two parameters and execution of a zero/start point during start-up. instruction manual - HBDF mk2 defrost sensor (005-UK) 1 / 14
Table of Contents Instruction Manual... 1 HBDF MK2 Defrost Sensor... 1 For automatic defrosting of evaporators... 1 Table of Contents... 2 Safety Instructions... 3 Introduction... 4 Measuring Principle... 5 Design... 5 Software... 5 Technical Data... 6 Function... 7 Installation Instructions... 8 HBDF-snapON Clips... 8 Parameter settings... 9 Electrical connection... 10 Application examples... 11 Simple defrost with electric heater... 12 LED Indication and Calibration... 12 LED indication... 13 Fault Detection... 13 Sensor Repair... 14 Spare Parts... 14 Further Information... 14 instruction manual - HBDF mk2 defrost sensor (005-UK) 2 / 14
Safety Instructions CAUTION! Always read the operational guidelines before commencing work! Read all warnings Installation of HBDF requires technical knowledge of both refrigeration and electronics. Only qualified personnel should work with the product. The technician must be aware of the consequences of an improperly installed sensor and must be committed to adhering to the applicable local legislation. If changes are made to type-approved equipment, this type approval becomes void. The product's input and output, as well as its accessories, may only be connected as shown in this guide. HB Products assumes no responsibility for damages resulting from not adhering to the above. Explanation of the symbol for safety instructions. In this guide, the symbol below is used to point out important safety instructions for the user. It will always be found in places in the chapters where the information is relevant. The safety instructions and the warnings in particular, must always be read and adhered to. CAUTION! Refers to a possible limitation of functionality or risk in usage. NOTE! Contains important additional information about the product and provides further tips. The person responsible for operation must commit to adhering to all the legislative requirements, preventing accidents, and doing everything so as to avoid damage to people and materials. Intended use, terms of use. The HBDF defrosting sensor is designed for measuring ice formation on evaporators. If the HBDF is to be used in a different way and if the operation of the product in this function is determined to be problematic, prior approval must be obtained from HB Products. Defrosting with hot gas must be performed in a safe way in order to ensure that there is no risk for liquid hammering and leakage of refrigerant. Preventing collateral damage: Make sure that qualified personnel assess any faults and take necessary precautions before attempting to make replacements or repairs, so as to avoid collateral damage. Disposal instructions: HBDF is constructed so that the modules can easily be removed and sorted for disposal. instruction manual - HBDF mk2 defrost sensor (005-UK) 3 / 14
Introduction HBDF is an intelligent sensor with a built-in microprocessor. It is designed to measure ice formation on evaporators (Air-Coolers). It emits a 4-20 ma signal. Apart from the 4-20 ma signal, the sensor also has built-in relays for start/stop defrost and external temperature sensor for measuring when the ice is melted. Example showing the HBDF MK2 configuration tool Enable start / stop input, set to ON Disable relay out Start defrost, 50% = 1.5mm Defrost stop temperatur Frost mode delay Simple calibration, only use these two parameters. Active wire length Distance between fins Setup is very simple, only two parameters and execution of a zero/start point and a Calibration with frozen/dry evaporator surface (surface with thin layer of frozen ice as after defrost is the optimal start point). The length of the wire entered is only the wire between the fins, and not the free wire in the bending. instruction manual - HBDF mk2 defrost sensor (005-UK) 4 / 14
Measuring Principle The sensor is a capacitive sensor. The capacitive measurement principle is based on the electrical properties in the proximity of a capacitor. A capacitor is an electrical component that is capable of building and retaining an electrical charge. A capacitor basically consists of two plates. When a charge is applied to one plate, the other plate will be charged with the opposite polarity and retain the charge until it has been grounded. The magnitude of the charge that can be generated (the capacitance) depends, among other things, on what is found between the plates. The substance between the plates is referred to as a dielectric. Rather than two plates, sensors for level measurement are usually shaped as cylindrical rods. When liquid covers the sensor, the measured capacity is changed. The conductivity of a material can vary depending on temperature, chemical composition, and the homogeneity of the material, and therefore it can require a different factory calibration in some cases. Sensors from HB Products are calibrated so that they differentiate between conductive and non-conductive liquids. In refrigeration systems, oil and liquid CO 2 and HFC are not regarded as conductive fluids, whereas refrigerants such as ammonia and brine are regarded as conductive fluids. Design The sensor consists of a mechanical part (wire) and an electronic part. These can easily be separated by loosening the cover on the electronic box. The electronic part is designed in accordance with IP65 waterproof rating, heater and to resist vibrations. Software The sensor is delivered with the latest firmware. The sensor can be set up with a configuration tool, "HB Tool", by using a PC. Once you are online and connected to the program the software will be automatically ask for update. The newest version of the tool is backwards compatible. instruction manual - HBDF mk2 defrost sensor (005-UK) 5 / 14
Technical Data Supply voltage: Electricity consumption: Electrical connection: Analogue output: Max. load: Relay output: Relay output 24V: Installation conditions: Ambient temperature: Waterproof rating: Vibrations: 24 V AC/DC 600 ma Screw terminals 4-20 ma 500 ohm 2 x 5A, NO/NC 2 x 3A, NO/NC -30 +50 C IP65 IEC 68-2-6 (4g) Certifications: EMC Emission: EMC Immunity: EN61000-3-2 EN61000-4-2 Mechanical specifications: Materials mechanical parts: AISI304 Materials electronic parts: Nylon 6 (PA) Configuration & indication: Configuration with push button Configuration PC with HB-TOOL LED Indication green, and red Cable entry: PG9 / M12 Note! All terminals are protected against improper termination for a supply voltage up to 40 V. If the supply voltage is higher than 40 V, the electronics will be damaged. instruction manual - HBDF mk2 defrost sensor (005-UK) 6 / 14
Function HBDF measures the build-up of ice between the fins of the evaporator. The sensor is installed and calibrated for the currently installed evaporator. At start-up, it is usually enough to perform the simple start up procedure as shown in the introduction section. Graphical view of a typical sequence on an air cooler: Advanced Calibration: The calibration should be carried out before ice begins to build up. When the evaporator is free of ice, the sensor emits 4mA. Depending on the ice build-up, the sensor emits up to 20mA or 18mA (when set to ma only mode). A visual inspection must be carried out to determine when defrost should be performed, and the system s defrost control (PLC) should be set to perform defrost at that given signal level (for example 12 ma). Defrost must be stopped when outside coil temperature is above 5 to 10 C. After fan delay where remaining water droplets from the melted frost is frozen to the surface of the evaporator, here the signal is 4 to 5mA indicating clean evaporator without ice. The built-in relays can be used to activate simple defrost control or digital input to an external defrost controller (Replace a timer) instruction manual - HBDF mk2 defrost sensor (005-UK) 7 / 14
Installation Instructions The following applies to system design: 1) The sensor box is installed on the evaporator s frame. 2) Ground wire should be connected to the frame with a stainless screw. 3) The wire is installed between the fins, where ice build-up occurs, the wire could be fixed with a special HBDF wire-clips or standard nylon (PA6) wire strips. 4) Normal installed with a standard unshielded cable. If the EMC is higher than described in EN 61326, a shielded cable must be used. Note: To have a good rigid ground connection, we recommend using stainless screw with a star washer/disc and cover/applying silicone grease/compound around the connection to avoid corrosion. HBDF-snapON Clips Not included The active part of the wire is the length between the fins. The wire must be placed between the fins, the distance of each can be freely chosen between 100 to 500mm depending on evaporator size and wire length. instruction manual - HBDF mk2 defrost sensor (005-UK) 8 / 14
Parameter settings Parameter Enable Start/Stop function Enable ma only function Defrost Start in % Defrost stop temp. Sensor delay in min. Sensor lenght in mm. Distance between fins in mm. Description Activate/deactivate the measuring and set the ma output to 4mA, and set the digital relays to default. Turn off the digital relays and also the timers. Only running with ma output. Defrost start in % where the digital start relay is activated and the ma is lock when it get to the defrost start level. E.g. 50% stops the ma output at 12mA. Defrost stop temperature when the digital stop relay is activated and the sensor delay starts running. Sensor delay is used for the time after defrost before the sensor is activating the measuring again. The start and stop relay is deactivated after timeout. The total length of the wire between the fins. Distance between fins in mm. CAUTION! In case of welding on the system, disconnect the power supply so that the electronics are not damaged during welding. instruction manual - HBDF mk2 defrost sensor (005-UK) 9 / 14
Electrical connection The HBDF MK2 sensor measures ice formation on evaporators (Air-Coolers). It emits a 4-20 ma signal. Apart from the 4-20 ma signal, the sensor also has built-in relays for start/stop defrost and external temperature sensor for measuring when the ice is melted. Should normally be used with a master defrost controller or a PLC, simple defrost with electric heater can be controlled directly as shown in application on page 11. instruction manual - HBDF mk2 defrost sensor (005-UK) 10 / 14
Application examples Safety: Defrosting with hot gas must be performed in a safe way in order to ensure that there is no risk for liquid hammering and leakage of refrigerant. instruction manual - HBDF mk2 defrost sensor (005-UK) 11 / 14
Simple defrost with electric heater The HBDF-MK2 sensor is primarily designed to measure ice thickness where the analogue 4-20mA output indicates the ice thickness, the built-in relays are usually used for start and stop signal of an external defrost timer or controller. Simple defrost with electric heater and adjustable fan delay is possible. LED Indication and Calibration instruction manual - HBDF mk2 defrost sensor (005-UK) 12 / 14
LED indication 1) Green LED, flash indicates power supply, And DI external start signal is ON. 2) Red LED indicates Defrost mode or sensor error (Outside measuring range). LED signal ON/OFF/Frequency Functionality Green On or flash Supply voltage connected Flash (Run-In mode) Run-in start signal / operation. OFF No supply voltage Red Flash Defrost mode start Flash quickly Defrost mode stop OFF Defrost fan/sensor delay (timer end) Fault Detection Fault Reason Correction of fault No LED is on / no function No supply to the sensor or defective cable. Check for fault in the power supply or replace the supply cable. Red LED are flashing Power supply is too small. Install a power supply with a capacity of at least 30 W. No AO, ma output or Relay There may be bad ground connection Clean the metal surface and protect it contact activation to the frame. with special compound/grease. Practical measurement of output signals: 4-20 ma signal: Function and stability of the 4-20 ma signal can be checked by connecting a hand-held multimeter. If the supply is connected and the power LED flashes and there is no output signal, the electronics may be defective. instruction manual - HBDF mk2 defrost sensor (005-UK) 13 / 14
Sensor Repair In case of defects with the sensor, it will typically only be necessary to replace the electronical part. Complaints are processed by HB Products dealers/distributors. Please consider their complaint procedures before returning the sensor. Spare Parts Position Designation Specification Product number 1 Mechanical part 10 m wire HBDF-MEK-10M Mechanical part 20 m wire HBDF-MEK-20M Mechanical part 30 m wire HBDF-MEK-30M 2 Electronic part PCB HBDF-MK2-EL 3 Temp. sensor Pt1000-Cable type HBPT-Pt1000 cable 4 Communication cable HB USB cable HBxC-USB Further Information For further information, please visit our website, www.hbproducts.dk, or send an email to: support@hbproducts.dk. HB Products A/S Bøgekildevej 21 DK8361 Hasselager support@hbproducts.dk www.hbproducts.dk instruction manual - HBDF mk2 defrost sensor (005-UK) 14 / 14