KPS79 Danfoss Temperature Switch IP67 50-100°C

Product Overview

The Danfoss KPS79 is a mechanical industrial temperature switch / thermostat designed for reliable temperature monitoring, alarm and control applications. The KPS family is engineered for demanding environments where a high enclosure rating, robust construction, and resistance to shock and vibration are required.

The KPS79 provides a 50–100°C temperature setting range, an adjustable mechanical differential of 4–16°C, and a maximum sensor temperature of 200°C. The current Danfoss documentation specifies an SPDT gold-plated contact system, IP67 enclosure protection and an operating ambient temperature range of -40 to +70°C.

Danfoss positions the KPS family for monitoring, alarm and control systems in factories, diesel plants, compressors, power stations and marine equipment. Its mechanical construction is specifically intended to tolerate the shock and vibration associated with ships, compressors and large machinery.

The supplied codes 060L3105 and 060L3121 require particular attention during replacement. Current Danfoss documentation identifies the corresponding complete codes as 060L310566 and 060L312166, representing different KPS79 sensor configurations. Therefore, complete-code verification is essential before ordering a direct replacement.

Technical Specifications (Bulleted List)

KPS79

• Manufacturer: Danfoss
• Product Type: KPS79 Thermostat / Temperature Switch
• Control Principle: Mechanical temperature-controlled SPDT switch
• Temperature Setting Range: 50–100°C
• Adjustable Differential: 4–16°C
• Maximum Sensor Temperature: 200°C
• Contact Function: SPDT
• Contact Material: Gold-plated silver
• AC-1 Contact Rating: 10 A, 440 V
• AC-3 Contact Rating: 6 A, 440 V
• AC-15 Contact Rating: 4 A, 440 V
• DC-13 Rating: 12 W, 220 V
• Maximum Starting Current: 50 A, locked rotor
• Ambient Temperature: -40 to +70°C
• Enclosure: IP67
• Applicable Standard: EN 60529 / IEC 60529
• Housing: Enamelled pressure die-cast aluminium, GID-AlSi 12
• Cable Entry: 5–14 mm cable diameter
• Electrical Entry: Pg 13.5
• Electrical Standard: EN 60947-5
• Sensor Diameter: approximately 13 mm
• Standard Sensor Size: approximately 13 × 63 mm
• Reset: Automatic for the cited KPS79 configuration
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Hydraulic Pressure Rating: Not applicable

KPS79 — 060L3121

The shortened code 060L3121 corresponds to the complete Danfoss code 060L312166 in the current ordering documentation.

• Complete Code: 060L312166
• Sensor Type: Rigid sensor
• Temperature Range: 50–100°C
• Adjustable Differential: 4–16°C
• Maximum Sensor Temperature: 200°C
• Sensor Size: 13 × 63 mm
• Sensor Pocket: 75 mm
• Contact: SPDT gold
• Reset: Automatic
• Enclosure: IP67
• Ambient Temperature: -40 to +70°C
• Sensor Connection: M18 × 1.5
• Electrical Entry: Pg13.5
• Net Weight: approximately 0.792 kg
• Gross Weight: approximately 0.882 kg

KPS79 — 060L3105

The abbreviated 060L3105 corresponds to the complete remote-sensor code 060L310566 in the Danfoss ordering data.

• Complete Code: 060L310566
• Sensor Type: Remote sensor
• Temperature Range: 50–100°C
• Adjustable Differential: 4–16°C
• Maximum Sensor Temperature: 200°C
• Sensor Size: 13 × 63 mm
• Capillary Length: 2 m
• Contact: SPDT gold
• Enclosure: IP67
• Ambient Temperature: -40 to +70°C

Related KPS Models

• KPS76: -10–30°C; differential 3–10°C; maximum sensor temperature 80°C
• KPS77: 20–60°C; differential 3–14°C; maximum sensor temperature 130°C
• KPS79: 50–100°C; differential 4–16°C; maximum sensor temperature 200°C
• KPS80: 70–120°C; differential 4.5–18°C; maximum sensor temperature 220°C
• KPS83: 100–200°C; differential 6.5–30°C; maximum sensor temperature 300°C

Key Technical Advantages

1. IP67 Protection

The KPS thermostat housing is rated IP67 according to EN 60529 / IEC 60529, providing high protection against dust and water ingress for industrial installations.

2. Shock and Vibration Resistance

Danfoss specifies vibration stability from 2–30 Hz at 1.1 mm amplitude and 30–300 Hz at 4 g for the KPS thermostat platform. The design is intended for demanding machinery and marine installations where mechanical vibration and shock are unavoidable.

3. Adjustable Mechanical Differential

The KPS79 offers a 4–16°C adjustable mechanical differential. Correct differential selection is important for preventing excessive switching frequency while maintaining acceptable process-temperature variation.

4. Gold-Plated Silver Contacts

The SPDT switching mechanism uses gold-plated silver contacts and supports ratings up to 10 A at 440 V AC-1, 6 A at 440 V AC-3 and 4 A at 440 V AC-15.

5. Heavy-Duty Die-Cast Aluminium Housing

The thermostat housing is manufactured from enamelled pressure die-cast aluminium GID-AlSi 12, providing a mechanically robust enclosure suitable for industrial installation.

6. Long-Term Switching Stability

Danfoss specifies KPS79 scale accuracy of approximately ±3°C and a maximum snap-point drift of 2°C after 400,000 operations under the specified laboratory test conditions. These figures should be interpreted as controlled test data rather than a universal field accuracy guarantee.

7. Multiple Sensor Configurations

KPS thermostats are available with rigid sensors and remote capillary sensors in several lengths and sensor-pocket configurations. This allows the sensing element to be positioned according to equipment geometry and process conditions.

Application Areas

The KPS79 and related KPS thermostats are suitable for:

• Industrial temperature monitoring
• Factory alarm and control systems
• Diesel engines and diesel plants
• Compressors
• Power stations
• Industrial heating equipment
• Process temperature control
• Marine equipment
• Shipboard monitoring systems
• Large machinery
• Cooling-water monitoring systems
• Thermal alarm circuits

Danfoss documentation specifically identifies factories, diesel plants, compressors, power stations and ships as target environments for the KPS product family.

The KPS product family also carries multiple marine approvals, including a DNV type approval covering KPS76, KPS77, KPS79, KPS80, KPS81 and KPS83. The approval identifies IP67 enclosure capability and suitability for marine installation.

Expert Maintenance Tips

Verify the full ordering code before replacement.
For legacy references such as 060L3105 and 060L3121, confirm the complete code and sensor configuration. The current complete codes 060L310566 and 060L312166 represent different KPS79 sensor arrangements.

Install the thermostat securely.
Remote-sensor versions use a 3 mm steel mounting plate for fixing to bulkheads or machine structures. The thermostat should not be mechanically supported by the sensing connection alone.

Position the sensor correctly.
Danfoss recommends positioning the sensor axis as close as practical to perpendicular to the direction of medium flow, helping maintain consistent heat transfer.

Correct for extreme ambient temperatures.
The adsorption charge used by KPS thermostats can lead to scale deviation when the ambient temperature becomes extreme. Danfoss provides correction factors for such operating conditions.

Select the differential according to the thermal dynamics of the system.
A differential that is too small may cause hunting or short cycling, while an excessive differential can produce unnecessary temperature variation.

Protect the sensor from excessive steam temperature.
For steam installations, Danfoss recommends a water-filled loop to protect the temperature-sensitive element from excessive heat transfer.

For replacement supply, validate the unit under representative operating conditions.
A professional replacement check should verify temperature switching point, differential, contact switching, sensor installation, ambient conditions and prolonged cycling. This supports reliable in-place interchangeability instead of relying only on the model number or external dimensions.