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 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.
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.
With the help of the KRIWAN INTspector app, you can collect and store the operating data of your refrigerant compressor. This enables you to carry out fast and targeted fault and condition diagnose on site. Via a gateway (USB or Bluetooth), you connect the INT280 with the INTspector app and thus, can access all important operating data and make adjustments to the parameters of the sensor inputs.
Thereby, you have the possibility to use the following functions:
Obtain all relevant operating data for your compressor - quickly, easily and reliably. For example, the "Diagnose Data" function allows you to retrieve extensive data on the oil level. Obtain information on the relative filling level, the last filling cycle time, the quantity of oil dispensed, and the average filling time.
You can also use the Diagnose data function to retrieve the following information:
All events such as errors, warnings and messages are stored in non-volatile memory and can be read out via the Diagnose Port and the INTspector app. Since each event is stored with a time stamp, it is possible to transparently trace which event occurred when. This supports on-site troubleshooting, for example, by enabling rapid troubleshooting.
Display of the operating time with active run detection or inactive run detection, as well as recording of the filling cycle times.
History fill cycles
Information on the number of filling cycles and the sum of the filling time.
In the Live Diagnose, all sensor data is recorded over time and can be viewed here. This supports rapid troubleshooting and provides information about the status of the device being monitored. You can see the fill level, valve status, filling time and pause time of your INT280 oil level regulator in real time. All sensor data is also written to a text file.
You have the option of individually parameterizing various control parameters of your INT280. This allows you to respond to different application situations with the greatest possible flexibility. Even complex application problems can be solved by fine-tuning various parameters.
We would like to show you some possible parameters as an example, which you can set completely flexible to your requirements.
With the "Adaptive" filling cycle type set as standard, the "INT280-xxx" calculates the optimum filling and pause times itself. The times are calculated so that the set target number of filling periods is reached. If the filling cycle type is changed to "Fixed", the filling cycle runs with the set filling and pause time.
Time for which the solenoid valve is opened cyclically in the event of an oil shortage.
Time for which the solenoid valve is cyclically opened in the event of an oil shortage.
Alarm delay time oil low
If oil shortage is detected, this time is started. When the time has elapsed, the relay switches off the compressor. If the "Alarm monitoring only when compressor is running" function is active, the time is stopped when the compressor stops. When the compressor starts again, it continues to run.
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 |
|60 bar |
|Cable 1m, 3m, 5m |
Without cable, Terminal in INT280
|With diagnostic function |
Without diagnostic function
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.
|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.
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.
|Connection thread||Article number|
|1 1/8"- 12 UNF||02K500S21|
|1 1/8"- 18 UNEF||02K502S21|
|1 1/4"- 12 UNF||02K505S21|
|1 3/4"- 12 UNF||02K504S21|
|3/4"- 14 NPT|| |
|Distance adapter 25mm||02K507S021|
|Cable type||Article number|
|DP-Y cable 600V||FK02098076|
Other DP cable types on request!