New 1PCS KRIWAN INT389R 52A 180 Compressor Protection Module Protector

Engineer's Quick Brief

• Comprehensive Motor Protection: The KRIWAN INT389R actively monitors both motor winding temperatures (via PTC thermistors) and phase sequences, immediately shutting down the compressor relay to prevent catastrophic motor burnout.
• DIN 44081/44082 Compliant: Engineered to interface directly with standard 1-9 series PTC thermistors. It features factory-calibrated trip thresholds (>4.5 kΩ) and reset hysteresis (<2.75 kΩ) to ensure the motor cools sufficiently before restarting.
• OEM Direct Replacement: The specific 52A 180 designation is a highly standardized configuration widely utilized as original equipment in leading industrial refrigeration compressors, including Bitzer and Hanbell screw/scroll units.

SEO Introduction

The KRIWAN INT389R (Part Number: 52A 180) is an industrial-grade, multifunctional Compressor Protection Module essential for safeguarding high-value HVAC and industrial refrigeration equipment. Acting as the electronic brain of the compressor's safety circuit, this module simultaneously monitors the three-phase power supply for phase loss/asymmetry and tracks the motor winding temperature via embedded PTC thermistors. If a phase failure occurs or the motor temperature exceeds the safe thermal limit (driving the PTC resistance above 4.5 kΩ), the INT389R instantly trips its internal relay, disengaging the compressor contactor. Manufactured in Germany to exact OEM specifications, this replacement module restores critical fail-safe protection to chiller plants, cold storage facilities, and heavy-duty heat pumps, ensuring long-term operational reliability and preventing extremely costly motor rewinds.

Technical Specifications

Application Matrix

• Commercial Chillers & Heat Pumps: Protects large-scale screw and scroll compressors from voltage imbalances that cause excessive heat generation in the motor windings.
• Industrial Cold Storage: Provides 24/7 monitoring in critical food-processing refrigeration racks, ensuring phase loss (often caused by blown fuses on the grid) does not result in a locked-rotor burnout.
• OEM Equipment Servicing: Serves as a direct, plug-and-play replacement for factory-installed protection modules in Bitzer, Refcomp, and Hanbell compressor terminal boxes.

KRIWAN INT389R PTC & Phase Diagnostic Tool

Refrigeration technicians can use this tool to quickly determine the state of the INT389R module. Enter the total resistance of the PTC thermistor chain measured with your multimeter and select the current phase status to reveal the module's diagnostic logic.

Troubleshooting & FAQ

• How do I test if the KRIWAN INT389R is defective or if the compressor is actually overheating? Unplug the orange PTC sensor wires from the module. Use a multimeter to measure the resistance across the sensor wires going into the motor. If the resistance is very high (e.g., >4.5 kΩ or Open Line), the motor is genuinely overheated or a sensor is broken. If the resistance is normal (<1.8 kΩ) and the phase sequence is correct, but the module's relay remains open (no continuity across the switch terminals), the KRIWAN module has failed and must be replaced.
• Can I temporarily bypass the INT389R module to get the compressor running? ABSOLUTELY NOT. Bypassing the protection module removes the only line of defense against thermal runaway and phase faults. Running a compressor with a bypassed module will almost certainly result in catastrophic motor winding destruction, turning a minor module replacement into a massive compressor rebuild.
• The module trips immediately on startup, but the motor is cold. Why? If the motor is cold (PTC resistance is verified low) but the module trips instantly, check the phase sequence. The INT389R actively monitors L1, L2, and L3. If two phases are reversed, or one phase has a blown fuse (phase loss), the module will lock out the relay to prevent reverse rotation or single-phasing.
• What does a PTC resistance of "0 Ohms" mean? A reading of 0 to 30 Ohms across the sensor wires indicates a direct short circuit in the PTC thermistor chain or the wiring harness. The KRIWAN module is designed to detect this and will trip the relay, recognizing that the temperature monitoring circuit is compromised.

Cross-Reference & Selection Guide

When replacing compressor protection modules, strict adherence to OEM specifications is required to prevent nuisance tripping or loss of protection:

• Voltage Verification: The "52A 180" typically covers standard AC 115-230V applications. Always verify the supply voltage printed on the side of your old module. Installing a 115V/230V module into a 24V control circuit (or vice versa) will destroy the unit or prevent it from powering on.
• OEM Equivalents: This module is functionally compatible with many OEM-branded modules found on Bitzer (e.g., SE-B1 / SE-B2 equivalents, depending on exact wiring), provided the PTC trip curve and phase monitoring requirements match.
• Legacy Upgrades: If replacing an older INT69 series, note that the INT389R often integrates phase monitoring directly into the module, which may require minor wiring harness updates if the older setup used external phase relays.