ETS326-3-100-000 ETS328-5-100-000 ETS388-5-150-000 Hydac Temperature Switch 600 bar

Product Overview

The ETS series electronic temperature switches are compact temperature measurement and control devices engineered by HYDAC for industrial hydraulic and process control applications. Featuring integrated high-precision temperature sensors with digital displays and push-button programming for independent adjustment of switching points and hysteresis, these devices are widely used for hydraulic oil temperature monitoring, cooling system control, and process temperature protection.

The ETS series covers multiple sub-series including ETS326 (3-digit display), ETS328 (3-digit display), ETS388 (3-digit display) , and ETS3866 (4-digit display) . The ETS326/ETS328/ETS388 models feature integrated 18 mm temperature probes with pressure resistance up to 600 bar, enabling direct installation in pipelines or on hydraulic manifolds. The ETS3866 features a remote probe design compatible with TFP 100 temperature probes, extending the measuring range to -30°C to +150°C.

Our complete range of HYDAC ETS electronic temperature switches strictly adheres to OEM technical standards, achieving 100% direct interchangeability with original components. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring performance parameters are fully consistent with genuine HYDAC products. Direct replacement of same-model HYDAC temperature switches significantly reduces equipment downtime and maintenance costs.

⚠️ Model Code Decoding (using ETS326-3-100-000 as example) :

• ETS = Electronic Temperature Switch

• 326 = Series code (326/328/388/3866, etc.)

• 3 = Number of switching outputs (2 = 2 switch outputs; 3 = 2 switch outputs + 1 analog output)

• 100 = Temperature probe length (mm), e.g., 100mm

• 000 = Configuration/sealing code

Technical Specifications 

ETS326-3-100-000

• Product Series: HYDAC ETS326 series electronic temperature switch

• Model Code: ETS326-3-100-000

• Brand: HYDAC

• Product Type: Electronic temperature switch

• Display: 3-digit digital display

• Temperature Probe: Integrated, length 18 mm

• Measuring Range: -25°C to +100°C

• Pressure Resistance: 600 bar

• Switching Outputs: 2 PNP transistor switching outputs + 1 analog output (4-20mA)

• Switching Load: Up to 1.2A per output

• Accuracy: ±1％FS

• Repeatability (at 25°C) : ≤±0.1％FS

• Temperature Drift: ≤±0.03％FS/°C

• Installation Torque: 45 Nm

• Ingress Protection: IP65

• Weight: Approx. 0.5 kg

ETS328-5-100-000

• Product Series: HYDAC ETS328 series electronic temperature switch

• Model Code: ETS328-5-100-000

• Brand: HYDAC

• Product Type: Electronic temperature switch

• Display: 3-digit digital display

• Temperature Probe: Integrated, length 18 mm

• Measuring Range: -25°C to +100°C

• Pressure Resistance: 600 bar

• Switching Outputs: 2 PNP transistor switching outputs

• Switching Load: Up to 1.2A per output

• Analog Output: Optional 4-20mA / 0-10V

• Accuracy: ±1％FS

• Mounting Type: In-line piping or hydraulic manifold mounting

• Ingress Protection: IP65

ETS388-5-150-000

• Product Series: HYDAC ETS388 series electronic temperature switch

• Model Code: ETS388-5-150-000

• Brand: HYDAC

• Product Type: Electronic temperature switch

• Display: 3-digit digital display

• Temperature Probe: Integrated (built-in temperature sensor)

• Measuring Range: -25°C to +100°C (integrated); -30°C to +150°C (remote)

• Pressure Resistance: 600 bar

• Switching Outputs: 2 PNP transistor switching outputs

• Switching Load: Up to 1.2A per output

• Analog Output: Optional 4-20mA / 0-10V

• Accuracy (Display/Analog Output) : ≤±1.0°C

• Temperature Drift (Ambient) : ≤±0.015% FS/°C

• Measuring Element: Pt1000

• Response Time: < 500 ms

ETS3866-3-000-000

• Product Series: HYDAC ETS3800 series electronic temperature switch

• Model Code: ETS3866-3-000-000

• Brand: HYDAC

• Product Type: Electronic temperature switch

• Display: 4-digit digital display

• Temperature Probe: Remote (compatible with TFP 100 temperature probe)

• Measuring Range: -30°C to +150°C (remote probe)

• Switching Outputs: 1 switching output + 1 analog output (4-20mA / 0-10V)

• Electrical Connection: M12×1 / 4p

• Mechanical Connection: None (remote type)

• Certification: UL approved

• Ingress Protection: IP65

Key Technical Advantages

1. High-Precision Temperature Measurement with Digital Display
The ETS series integrates high-precision temperature sensors with accuracy up to ±1％FS (ETS326/ETS328) or ±1.0°C (ETS388). The ETS326 achieves repeatability of ≤±0.1％FS at 25°C. The 3-digit or 4-digit digital display provides intuitive real-time temperature readings for convenient on-site monitoring and fault diagnosis.

2. 600 bar Ultra-High Pressure Resistance for High-Pressure Hydraulic Systems
ETS326/ETS328/ETS388 integrated models feature 18 mm integrated temperature probes with pressure resistance up to 600 bar. This enables direct installation in high-pressure pipelines or hydraulic manifolds without additional pressure reduction devices, making them particularly suitable for oil temperature monitoring in construction machinery, injection molding machines, and other high-pressure hydraulic systems.

3. Flexible Switching and Analog Output Configurations
The ETS series offers 1 or 2 PNP transistor switching outputs, each capable of handling loads up to 1.2 A. Optional 4-20mA or 0-10V analog outputs facilitate integration with PLCs, DCS, and other control systems. Switching points and hysteresis can be independently adjusted via push-button programming to meet diverse application control requirements.

4. Compact Rugged Design for Harsh Environments
The ETS series features a compact rugged design with IP65 ingress protection. The ETS388 is equipped with a Pt1000 measuring element with response time < 500 ms. The full series offers excellent vibration resistance and EMC characteristics, making it suitable for harsh industrial environments including construction and mining equipment.

5. 100% Direct Interchangeability and Simulated Condition Testing
All models strictly adhere to HYDAC original mounting dimensions and interface standards, enabling direct drop-in replacement of original temperature switches without piping modification or system adjustment. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring consistent, stable performance at rated temperature and pressure.

Application Areas

• Hydraulic System Oil Temperature Monitoring: Tank temperature monitoring and cooling system control for hydraulic power units

• Construction Machinery: Hydraulic oil temperature monitoring and overheat protection for excavators, wheel loaders, cranes

• Injection Molding Machinery: Hydraulic system temperature control and cooling circuit management for injection molding and die-casting machines

• Lubrication Systems: Temperature monitoring and alarm for industrial gearboxes and bearing lubrication systems

• Process Control: Process temperature monitoring and control in chemical and pharmaceutical industries

• Wind Power: Gearbox oil temperature monitoring and cooling system control for wind turbines

• ETS3866 Series: Temperature monitoring for tanks and reservoirs requiring remote probe installation

Expert Maintenance Tips

1. Verify Model and Range Compatibility Prior to Installation
The ETS series includes both integrated (ETS326/ETS328/ETS388) and remote (ETS3866) probe configurations. Confirm that the model matches system requirements—integrated models offer -25°C to +100°C measuring range with 600 bar pressure resistance; the remote ETS3866 extends the measuring range to -30°C to +150°C.

2. Correct Installation Torque
ETS326/ETS328/ETS388 integrated models feature G1/2 DIN 3852 external thread connections. Use a torque wrench to tighten to the value specified in the technical manual—ETS326 recommended torque is 45 Nm. Never rotate the housing during installation, as this may damage internal sensing elements or the display unit.

3. Electrical Connection Precautions
The ETS series features M12×1 standard industrial connectors. Supply voltage is 9-35 VDC. Verify that supply voltage matches the model specifications and observe correct polarity prior to wiring. Analog outputs are configured as 4-20mA (2-wire) or 0-10V.

4. Probe Installation Depth
The 18 mm temperature probe on integrated models must be fully immersed in the medium. Ensure the probe tip does not touch the bottom or walls of the vessel to guarantee measurement accuracy. For ETS3866 remote models, ensure the external temperature probe (e.g., TFP 100) is correctly installed and securely connected.

5. Periodic Calibration and Inspection
Perform temperature calibration checks every 12 months or according to system criticality to verify deviation between displayed value and actual temperature. If deviation exceeds the accuracy specification, recalibrate or replace the sensor. Also inspect electrical connections for looseness and the probe for mechanical damage or corrosion.

6. Avoid Overtemperature Operation
Although integrated ETS models offer 600 bar pressure resistance, media temperature must not exceed +100°C (integrated) or +150°C (remote). Prolonged overtemperature operation will result in degraded sensor accuracy or permanent damage.