Level switches INT275 - INT279

Optical level monitoring is used for non-contact single-point measurement of liquid levels, e.g. in compressors, pumps, vessels, etc. The solution consists of two components, the screw-in part and the evaluation unit. The screw-in part for optical level detection is permanently installed at the measuring point. The electronic evaluation unit can be mounted or replaced without time-consuming evacuation of the system and draining of the oil.

The optical level monitoring devices from KRIWAN protect refrigerant compressors in particular from leakage, oil deposits in the refrigeration circuit or other malfunctions. The range includes different product versions for monitoring the liquid level in refrigerant compressors, oil and refrigerant receiver and oil separators.

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Advantages KRIWAN optical level switch

Operating principle level monitoring


The level switch 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.

The KRIWAN level switches are available in two configurations. Either they monitor the minimum level (as described above) or the maximum level, which shall not be exceeded.

Robust design or increased temperature requirements?

Select the appropriate optical level switch from our extensive product range.

Niveausensor Kältemittelsammler Robust design

INT276 ICN and INT276 ICX

Use on the refrigerant receiver

Moisture from the warm ambient air always condenses at the coldest point. If this happens to be the refrigerant receiver, this can lead to icing between the glass cone and the evaluation unit. A special product version has therefore been developed for this purpose. It is optimized for use on the CO₂ refrigerant receiver and is resistant to icing of the optical measuring principle.

Niveausensor für Hubkolben Kompressor Vibration resistant

INT279 LN and INT279 LX

Use on compressor

Universally applicable for oil management in systems with conventional refrigerants and compressor-typical temperature requirements.

Ölsammler Niveausensor Anlagenschutz Temperature resistant

INT276 CN+ and INT276 CX+

Use on the oil receiver

Oil management for natural refrigerants with high temperature requirements up to 140 °C e.g. CO2 or NH3. Also suitable for heat pumps with higher temperature requirements.

KRIWAN optical level switch - the right device for every application!

KRIWAN offers you a variety of optical level switches with different technical specifications. In the following table, you will find a small selection of our level switch.

Contact our specialists and we will find the right product together with you!

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Designation: INT275 L INT276 ICN INT276 ICX INT278 CAN EX INT278 LCA INT279 LN INT279 LX
Permissible media temperature max. +80°C max. +120°C (<16.000h) 
max. +100°C
max. +120°C (<16.000h) 
max. +100°C
max. +100°C
max. +100°C
max. +100°C
max. +100°C
Function min min max min min min max

Start-up bridging

no no no 90 sek. 90 sek. | 30 sek. no no
Switching delay 3 sek. 3 sek. 3 sek. 3 sek. 3 sek. 3 sek. 3 sek.
Interlocked shutdown no no no yes yes no no
Run detection no no no yes yes no no
Alarm contact

N/O contact 

Changeover Changeover Changeover Changeover Changeover Changeover
Connection cable length 1m 1m, 2m, 5m, 10m 1m, 5m, 10m 1m 1m, 3m 10m 10m
Certification UL no no UL, EX UL no no
Power supply

AC50/60 Hz 230V 

AC50/60 Hz 115V

AC/DC 50/60 Hz 24V

AC50/60 Hz 230V 

AC/DC 50/60 Hz 24V

AC50/60 Hz 230V 

AC/DC 50/60 Hz 24V

AC50/60 Hz 230V 

AC50/60 Hz 115V

AC50/60 Hz 230V 

AC50/60 Hz 115V

AC/DC 50/60 Hz 24V AC/DC 50/60 Hz 24V

Screw-in parts for INT275 - INT279 optical level switches

In addition to the evaluation unit, the two-component design also includes the matching screw-in part. Our screw-in parts for the optical level switches are available for different thread types and are suitable for natural refrigerants such as NH3 and CO2.

Einschraubteil für Niveausensoren

Thread NPT 1/2"

Article number Operating pressure Medium temperature
02K460S23 42 bar -30°C...+120°C
02K460S24 46 bar (-10°C…+120°C)
34,5 bar (-30°C…-10°C)
02K460S33 42 bar -30°C...+120°C
02K460S34 46 bar (-10°C…+120°C)
34,5 bar (-30°C…-10°C)
02K460S40 140 bar (-10°C…+120°C)
105 bar (-30°C…-10°C)


Thread NPT 3/4"

Article number Operating pressure Medium temperature
02K463S040 140 bar (-10°C…+120°C)
105 bar (-30°C…-10°C)

Thread UNEF 1 1/8"

Article number Operating pressure Medium temperature
02K462S21 46 bar -30°C...+120°C
02K462S40 140 bar (-10°C…+120°C)
105  bar (-30°C…-10°C)

Thread M20x1,5

Article number Operating pressure Medium temperature
02K465S21 42 bar -30°C...+120°C
02K465S22 46 bar (-10°C…+120°C)
34,5 bar (-30°C…-10°C)
02K465S24 63 (-10°C…+120°C)
48 bar (-60°C…-10°C)
02K465S40 140 bar (-10°C…+120°C)
105 bar (-30°C…-10°C)

Thread G1/2" SW27

Article number Operating pressure Medium temperature
02K466S021 60 bar (-10°C…+120°C)
45 bar (-30°C…-10°C)

Flange Part D38/ Rotalock 1 3/4"

Article number Operating pressure Medium temperature
02K461S21 42 bar (-10°C…+120°C)
31,5 bar (-30°C…-10°C)

KRIWAN Level Sensors

Gain precise insights into the liquid levels with our state-of-the-art level sensors. As a leading provider in the field, we offer innovative solutions for accurate and reliable level measurement in various applications. Our level sensors stand out for their advanced technology and high sensitivity, providing you with precise monitoring and control over your liquids.

Whether you are in the industrial sector, environmental protection, or other fields, our level sensors offer a versatile solution to meet your requirements. With a focus on quality and precision, our sensors enable efficient monitoring to optimize resources and reduce costs. Trust in our expertise to enhance the performance of your facilities while keeping a precise eye on the liquid levels.

Discover the benefits of our level sensors and get in touch with us to discuss customized solutions for your specific needs. We are here to ensure that you always have the optimal overview of your liquids.



Niveausensor Kältemittelsammler
Niveauüberwachung im Kältemittel- oder Ölsammler

Level Measurement for Your Facilities

Enhance your level measurement with our advanced level sensors. Our cutting-edge level sensors enable reliable level measurement, ensuring not only accuracy but also efficiency.

Our level measurement technology allows you to precisely determine the current level of your liquids, leading to optimized resource utilization and cost control. Regardless of the industry, our sensors offer tailored solutions to meet your specific requirements. We understand the importance of accurate level measurements for the smooth operation of your facilities, and our sensors are designed to help you maximize performance.

Rely on our experience and technology to elevate your level measurement to the next level. Contact us today to discuss customized solutions for your specific needs and optimize the efficiency of your level measurement.

FAQ to the optical level switch

Where are KRIWAN level switches used?

Often these are already installed on the compressor. However, they can also be used on pressure vessels such as oil collectors, refrigerant collectors or oil separators. For this purpose, we have screw-in parts certified in accordance with the Pressure Equipment Directive in our portfolio.

Which media can be monitored?

Refrigerant, oil, fruit juice, etc.

Do I need different versions of the level switch to monitor different media?

No, you don’t need to keep different versions of the level switch on stock. You can monitor refrigerant and oil with the same product.

Download documentation for INT275 - INT279 level switches

What possibilities do the KRIWAN INT275 - INT279 level switches offer in practice? Our application sheets provide interesting insights.


Niveauüberwachung im Kältemittel- oder Ölsammler Application sheet

Level monitoring in the refrigerant or oil receiver

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Schutzsensoren für den Einsatz am Verdichter Application sheet

Oil level monitoring without oil pump

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Trockenlaufschutz für Pumpen Application sheet

Dry running protection for pumps

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Schutzsensoren für Pumpenanlagen Brochure

HVAC/R protection solutions

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You have further questions? Our experts will be pleased to advise you!


Sebastian Sturm

Key Account Manager

+49 (0) 79 47 - 8 22 - 0