Panasonic SQ4-C11 Safety Liquid Leak Sensor Controller

Technical Overview

Safety liquid leak sensor controller, achieving Control Category 4/PLe/SIL3. Connects up to four SQ4-A sensors with 24VDC input and NPN/PNP outputs.

Key Features

Supports connection of up to 4 safety liquid leak sensors (SQ4-A series).
Operates on a 24V DC power supply.
Provides redundant outputs that are NPN/PNP selectable.
Designed for convenient DIN rail mounting.
Features a two-stage detection system, providing both a warning and a safety-critical output to differentiate leak severity.
Capable of detecting human errors, such as a dislodged, improperly installed, or broken sensor connection.
Utilizes semi-conductor output, eliminating the need for relay replacement.
Includes a safety input function for daisy-chaining multiple controllers and integrating with safety peripherals like E-stop switches.
Incorporates two independent CPUs for simultaneous monitoring of operating state and redundant signal processing for enhanced safety.

Technical Specification Matrix

Parameter	Value
Power Voltage	24V DC, Ripple P-P 10% or less
Consumption Current	200mA or less
Number of Connectable Sensors	4 units (SQ4-A series)
Control Output	PNP / NPN selectable
Safety Performance (with SQ4-A sensors)	Control Category 4, PLe, SIL3 (ISO 13849-1:2008)
Protection Rating (Bare Product)	IP20 (IEC)
Mounting Type	DIN Rail
Operating Temperature	-10°C to +55°C
Physical Weight (kg)	0.17
Dimensions L x W x H (cm)	8.9 x 2.9 x 9.58

Industrial Applications

1. Critical Equipment Leak Monitoring in Semiconductor Manufacturing

In semiconductor fabrication facilities, even minute leaks of hazardous chemicals or ultrapure water can cause significant contamination, equipment damage, or safety hazards. The SQ4-C11, with its ability to monitor up to four leak detection points and provide Category 4/PLe/SIL3 safety outputs, ensures rapid and reliable detection, triggering immediate shutdowns or alarms to prevent catastrophic events.

Problem Solved

Mitigates risks of contamination, equipment damage, and personnel exposure from liquid leaks around sensitive and hazardous processes, ensuring high safety integrity and operational continuity.

Semiconductor manufacturingHazardous chemical detectionUltrapure water leakCategory 4 safetySIL3Multi-point monitoring

2. Industrial Wastewater Treatment Plant Overflow Prevention

Wastewater treatment plants require stringent monitoring to prevent spills, tank overflows, and pipeline ruptures, which can lead to environmental contamination and regulatory fines. The SQ4-C11's capacity to connect multiple sensors across various critical points in the plant, combined with its two-stage detection (warning and emergency stop), provides a robust system for early leak detection and automated response.

Problem Solved

Prevents environmental pollution and operational disruption by reliably detecting liquid leaks and initiating timely safety actions in large-scale wastewater management systems.

Wastewater treatmentOverflow preventionEnvironmental complianceTwo-stage detectionEmergency shutdownIndustrial safety

3. Data Center Cooling System Leak Protection

Data centers rely on efficient cooling systems, and any leak can lead to severe damage to expensive IT infrastructure. The SQ4-C11's compact, DIN rail mountable design, 24VDC operation, and ability to connect up to four leak sensors make it an ideal solution for monitoring cooling racks, CRAC units, and raised floor areas. Its rapid safety outputs ensure quick response to prevent water damage to critical servers.

Problem Solved

Protects valuable data center equipment from water damage caused by leaks in cooling systems, ensuring continuous operation and preventing costly downtime.

Data center coolingLeak detectionIT infrastructure protectionDIN rail mount24VDCRapid response