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KRIWAN presents new products at AHR Expo 2017

Date: 03 February 2017

Oil level regulator KRIWAN

Measuring the oil level in the compressor and automatically refilling when the oil level is low is customary practice. However, the requirements of today are higher. The new INT280 oil level regulator of KRIWAN sets new standards and meets the latest demands.


Measuring the oil level in the compressor and automatically refilling when the oil level is low is customary practice. However, the requirements of today are higher. The new INT280 oil level regulator of KRIWAN sets new standards and meets the latest demands. An oil level regulator has a sensor that measures the current oil level in the compressor. If the oil level drops below the permissible lower limit, the regulator automatically opens an integrated solenoid valve and supplies oil from the oil reservoir until the necessary oil level is reached again. If it is not possible to refill the compressor with oil, the compressor is switched off to prevent damage. That is the customary procedure and for many years, this practice was fully adequate. However, the requirements have now been raised and new properties are required in oil management. In the development of the new INT280 oil level regulator, KRIWAN heeded the suggestions and wishes of the users in the practice. As a result, the oil level regulator sets new benchmarks and fulfills the latest wishes of the customers.

CO2 requires more flexibility In the products that were hitherto available on the market, it is not possible to adjust the opening time of the valve. However, very different pressure ranges in refrigeration circuits have become increasingly common with the growing use of transcritical CO2 systems and necessitate more flexibility. The time required for opening the solenoid valve and the number of switch operations of the valve significantly affect the precision and quality of the oil refill. Depending on the system (pressure ranges, type of lines or operating points), the ability to enter individual values might be required. The new INT280 of course also provides time-tested standard values as default setting. In many cases, these values provide very good results. However, it is possible to adapt these values by means of a smartphone app, should the system make it necessary. Thus the system installer can optimize the benefits to the customer by ensuring that the system is well-configured. This is possible both for “low” pressure ranges (60 bar for subcritical CO2 and other refrigerants) and “high” pressure ranges (130 bar for transcritical CO2).

Even easier to install The first INT280 already featured easy installation: The integrated transformer for mains voltage, the option of rotating the regulator 180° and the complete prewiring made it easy to install the INT280 at the compressor. All these advantages are of course still present in the new version, but several new plusses have been added: For example, the screws with which the oil level regulator is bolted in place are now much easier to turn with the tool. They no longer need to be grasped with an open-ended wrench, but can instead quickly be turned with a hexagon key. This saves time during installation. Another advantage is that the size in the installation direction has been significantly reduced. More space makes installation easier and also makes it possible to conveniently mount the regulator to narrow Scroll racks.

The KRIWAN Voltage Monitor INT69 UY

Increased current consumption, incorrect phase sequences, differing supply voltage – the causes of malfunctions and resulting damage in electrical systems are often down to these factors. KRIWAN is presenting new solutions that facilitate effective current and phase monitoring, and provide all electrically driven components with reliable protection against network problems in compact units such as chillers, condensing units, and refrigeration racks.

 In many applications, such as refrigeration/AC/ventilation technology, as well as process technology, the systems used are fully pre-mounted on a frame. The advantages of this are standardized manufacture in a factory, easier transportation of complete units to the point of use, and faster commissioning. These systems are connected to the same supply voltage with all of the compressors, pumps, valves, and heat exchangers that they use. In order to protect against damage caused by problems with the supply network, KRIWAN has developed a simple, compact, and extremely reliable plug-and-play solution for the entire system.

Phases and currents under control
The KRIWAN Voltage Monitor INT69 UY Diagnose is used in applications in which the monitored system may malfunction or be damaged as a result of excessive voltages or incorrect phase sequences. The voltage monitor checks whether the supply voltage is in the permitted voltage range and the correct phase sequence is present. If the maximum or minimum voltage thresholds are breached, or a phase error is detected, the INT69 UY switches off the system. The KRIWAN Motor Protector INT69 I2 Diagnose is used in applications in which the monitored system may malfunction or be damaged as a result of excessively high currents. The motor protection unit INT69 I2 Diagnose checks whether the current drawn by the motor is within the permitted limits. If an error is detected, it switches the system off. Through an additional input, any PTC sensors used for temperature monitoring can be evaluated. When the nominal response temperature (NRT) is reached, the system is switched off immediately. The protection units are also equipped with an integrated nonvolatile and tamper-proof operating data and error memory in order to be able to document real usage conditions, including problems occurring with the supply network.

New 5x Modbus Gateway

New refrigerants and energy saving measures are bringing new challenges for system installers and operators. Existing refrigeration systems have to be re-dimensioned because energy saving measures cause the refrigeration requirement to change, and tried-and-tested refrigerants are no longer available due to phase-out. Recording and diagnosing data from the compressor, and the entire refrigeration system, is a core part of solving these challenges. KRIWAN's Diagnose technology makes it possible to use valuable information to find errors faster, or even avoid them in the first place. KRIWAN has developed the tried-and-tested INT69 Diagnose compressor protection relay further. What is new is the fact that the compressor protection can now "grow" in line with requirements. Compressor protection has gone modular. Data can be read out from the compressor by means of a smartphone app. Another new feature is the fact that, with the help of a cable, the INT69 Diagnose can now be easily connected to the new INT280 oil level regulator, and a module for mechanical power control. This creates modular networking at the compressor.
Flexible chains, effective networking
 All of the data can now be passed on to the new Modbus Gateway INT600 DM together, and read into the refrigeration regulator. With five inputs, the gateway can process entire racks together, and send the data stream to the regulator. Each input on the Modbus Gateway can be connected to a chain of INT69 Diagnose, INT280 oil level regulator, and INT69 CC power control as described above. This allows a maximum of 15 devices in a rack to be connected to a single gateway. The set-up is fully configurable, and can be modularly adapted to suit the requirements on site. This new concept means that the refrigeration system installer can simply turn on the diagnosis system and monitor status on site in the event of changes to the system (new refrigerant, further energy saving). Remote monitoring allows experienced colleagues to provide on-site employees with assistance as required. Modular compressor protection is helping us to master the challenges of the future.  

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