What does Bitzer SE-B2 mean?

The SE-B2 is a basic BITZER compressor protection device that watches motor winding, discharge-gas and oil temperature via PTC sensors. If the preset temperature is exceeded, the device locks out immediately and stops the compressor. It also detects a broken sensor lead.

What does Bitzer SE-B3 mean?

The SE-B3 is a BITZER compressor protection device for 110-240 V supplies that monitors motor winding, discharge-gas and oil temperature. When the preset temperature is exceeded the device locks out immediately and stops the compressor.

What does Bitzer SE-B5 mean?

The SE-B5 is a BITZER compressor protection device compliant with EN/UL 60730. It monitors motor winding, discharge-gas and oil temperature and locks out immediately when the preset temperature is exceeded. It also provides broken-lead and cable-short-circuit monitoring of the temperature sensor.

How do I reset a Bitzer compressor after a fault?

After resolving the root cause, press and hold the reset button on the Bitzer control module for 3 seconds. For Bitzer CRII models with SABB, navigate to the fault log in the display and clear active faults. Always identify and fix the underlying fault before resetting to prevent repeated trips.

What causes a Bitzer screw compressor to trip on high discharge temperature?

High discharge temperature (E03) on Bitzer screw compressors is commonly caused by insufficient oil injection, a blocked oil separator, high compression ratio due to low suction pressure, or loss of economiser function. Check oil level and injection nozzles first, then verify suction pressure is within rated parameters.

How do I read the Bitzer LOGVIEW fault history?

Connect LOGVIEW software to the Bitzer CRII controller via RS485 or USB adapter. Navigate to the Fault History tab to see timestamped fault events with operating conditions at time of trip. This data is invaluable for diagnosing intermittent faults and trending compressor health.

What oil should I use in a Bitzer compressor with R404A?

Bitzer recommends BSE 55 or BSE 170 polyolester (POE) oil for R404A applications. Always use the viscosity grade specified on the compressor nameplate. POE oils are hygroscopic — keep containers sealed and replace oil if moisture contamination is suspected.

Quick Answer

Bitzer compressors diagnose through the SE-i, SE-B1, and SE-C1 protection modules on reciprocating units and the IQ Module on CSH / CSW / OS screw compressors. Faults latch into four categories: phase loss / direction, motor overload (PTC winding), oil temperature or oil flow loss, and discharge temperature or pressure relief — readable via LED, CM-RC-01, or LOGVIEW.

refrigeration

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By Nichita Herput

Co-founder & CEO · Reviewed May 2026

What error codes does Bitzer display?

SE-B2

Motor-protection device lockout (winding/discharge-gas/oil over-temperature)

SE-B3

Motor-protection device lockout (EN/UL 60730 successor to SE-B1/SE-B2)

SE-B5

EN/UL 60730 motor-protection device lockout (winding over-temperature / cable short)

SE-E4

Motor-protection device lockout with phase monitoring (200-690 V)

SE-E5

Motor-protection device with rotation, phase-failure and frequency-inverter support

SE-i1

Electronic protection module for CS. and HS. compressors (multi-parameter monitoring)

SE-G4

Motor-protection device for reciprocating compressors with phase monitoring

Common questions about Bitzer equipment

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