In refrigerant compressors, precise oil level control is of paramount importance. Our oil level regulators ensure precise monitoring and adjustment of the oil level to guarantee the optimal performance of your compressors. KRIWAN relies on pioneering technologies to establish the highest quality standards.
The INT280 monitors and regulates the oil level in refrigerant compressors. The oil level regulator is used in rack systems with several reciprocating or scroll compressors connected in parallel. Adaptive oil filling from a common oil reservoir prevents problems caused by uneven oil consumption of compressors in rack systems. In addition, the compressor is automatically switched off if it is not possible to restore the specified oil level.
The KRIWAN INT280 oil level regulator is available in different versions. Configure your device to suit your application. The table shows a selection of technical options.
| Supply voltage | Pressure | Electrical connection | UL approval | Diagnostic function |
| 230V AC 115V AC 24V AC | 60 bar 130 bar | Cable 1m, 3m, 5m Without cable, Terminal in INT280 Push-in connector | yes no | With diagnostic function Without diagnostic function |
In order to be able to use the oil level regulator flexibly in existing systems, we offer various adapters with standardized connection threads, including UNF and NPT adapters. For the optional connection of the INT280 with our Modbus gateway INT600 DM a DP-Y cable is required.
Information on this and other DP cable types is available on request.
You can find more information about our adapters here:
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The oil level regulator uses an infrared LED to determine whether the correct level is present. For this purpose, it uses the different refraction of the light at the glass cone, which is influenced by the presence oil or refrigerant.
In the "empty" state, the test signal is reflected with full intensity, since only gas is present as the medium. The evaluation unit detects the level as too low, e.g. the compressor or oil receiver might not contain enough oil.
In the "full" state, part of the test signal is absorbed by the medium. Less light reaches the receiver LED, and the evaluation unit recognizes the level as sufficient.
Your advantages
In CO2 racks, fixed filling times sometimes create challenges due to extensive oil foaming. The compressors and operating conditions can vary greatly and are influenced by different factors. The filling algorithm of the INT280 oil level regulator adapts its refilling behaviour within safe parameters based on previous experience. For example, too short filling cycles are avoided as foaming oil could not settle otherwise. As soon as sufficient oil is in the compressor, refilling is finished.
Another advantage of the KRIWAN INT280 oil level regulator: with the help of the INTspector app, adjustments to the basic algorithm can be made easily.
There is a version of the INT280 available that can be used in high pressure, transcritical CO2 systems.
KRIWAN offers the INT280 oil level regulator for systems with different pressure requirements. For systems with low operating pressure requirements, the INT280 oil level regulator is available up to 60bar. A KRIWAN oil level regulator INT280 is available for high pressure Co2 systems up to 130bar.
The INT280 oil level regulator has a very compact design. All components such as connection cables or valve coils are already installed at the factory. This means that integrated systems with scroll compressors can be planned and implemented in a very space-saving manner. In addition, two different installation options are possible, as the oil level regulator can be rotated by 180°.
You want to adjust software parameters such as the filling or pause times?
You can do this quickly and easily via the diagnostics interface using the KRIWAN INTspector app and a gateway.
The INT280 oil level regulator allows you to record and store relevant operating data. For example, you can validate how often and how long oil was topped up or whether it was necessary to shut down the compressor because, for example, not enough oil flowed in from the oil reservoir. The data can be retrieved on site via the KRIWAN INTspector app or integrated into the plant control system via a Modbus gateway.
Adaptive oil replenishment from a common oil reservoir prevents problems caused by uneven oil throw in compound systems. In addition, the compressor is automatically switched off if it is not possible to ensure the prescribed oil level.
| Malfunction | Possible cause | Rectification |
| Oil level in compressor too low although refilled | No oil in the oil collector | Refill oil, detect oil displacements |
| Oil level in compressor too low although refilled | Differential pressure is too low | Check if the differential pressure between oil receiver and compressor is high enough, adjust differential pressure valve |
| Compressor runs although there is not enough oil in the compressor for a long time | Alarm relay not in alarm chain | Correct connection |
| Alarm relay responds although compressor is stopped | No filling possible due to lack of pre-pressure | Use "INT280-xxx" diagnostics (run detection possible and thus no alarm when compressor is stopped). |
| Extraneous light interferes with the optical measuring principle | Outdoor installation of the device | Covering the sight glasses |
| Foreign object | A foreign object has entered the valve | KRIWAN filter attachment part number 02Z844S010 and 02Z844S020 available |
The oil level regulator fits a wide range of compressors due to its intended design of the 3/4-hole flange. For all other compressor variants KRIWAN offers suitable adapters, which are available separately. The adapter list can be found below in the accessories section.
No, all components are already installed at the factory in our plug-and-play solution.
The oil throw rate of a compressor is influenced by many factors such as ambient temperature, rack design, compressor speed or changes in refrigeration demand. The adaptive filling algorithm provides a remedy. After a certain filling time, longer pause times are used to wait until the system has settled down again and the foam has dissipated.
Thanks to its adaptive algorithm, the INT280 can also be optimally used in R744/CO₂ plants. With the help of this algorithm, the appropriate pause times can be determined, thus eliminating the problem of foaming. This reactive regulation makes sure that your system works flawlessly throughout all seasons of the year, no matter the cooling demand.
What possibilities does the KRIWAN INT280 oil level regulator offer in practice? Our application sheets provide interesting insights.
