Product Overview
The KPS 77 060L311866 (KPS 77) is a high-durability industrial thermostat from the Danfoss KPS series, specifically engineered for temperature control and alarm monitoring in heavy-duty maritime and industrial applications. Built to withstand extreme vibration and mechanical shock, this thermostat features an adjustable setting range of 20 to 60 Celsius and a robust sensing element. In environments such as engine rooms, pump stations, and industrial heating systems, the KPS 77 provides the reliability needed for critical process control. Its mechanical construction is optimized for longevity in harsh conditions, ensuring that setpoints remain stable despite the intense environmental stressors common in marine and offshore sectors.
Technical Configuration
The KPS 77 utilizes a vapor-charged sensing system with a specialized 75 mm sensor pocket compatibility for direct immersion into the medium. The internal mechanism features a high-grade microswitch that can be configured with an adjustable mechanical differential between 3 and 14 Celsius, allowing for precise tuning of the switching cycle to prevent frequent "hunting" of the actuator. The hardware is designed for direct mounting, and its enclosure provides high protection against dust and moisture ingress. With a maximum sensor temperature rating of 130 Celsius, the unit is protected against accidental thermal overruns, ensuring the internal bellows and linkage remain undamaged during temporary process upsets.
Technical Specifications
| Feature |
Specification |
| Model |
KPS 77 |
| Code No. |
060L311866 |
| Brand |
Danfoss |
| Product Type |
Temperature Switch / Thermostat |
| Setting Range |
20 to 60 deg C |
| Mechanical Differential |
3 to 14 deg C (Adjustable) |
| Max. Sensor Temp |
130 deg C |
| Sensor Pocket Length |
75 mm |
| Contact System |
SPDT (Single Pole Double Throw) |
| Reset Function |
Automatic |
| Vibration Resistance |
4 g (10-200 Hz) |
| Shipping Weight |
3.0 kg |
Technical FAQs
What is the benefit of an adjustable mechanical differential in the KPS 77?
The adjustable differential allows the engineer to set the distance between the "cut-in" and "cut-out" temperatures. A larger differential (up to 14 deg C) prevents the equipment from starting and stopping too frequently, which extends the life of motor starters and contactors in heavy-duty cooling or heating loops.
Can this thermostat be mounted directly on a vibrating engine block?
Yes, the KPS series is specifically designed for high-vibration environments. It is Marine Approved and built with internal dampening to ensure that vibration does not cause false tripping of the contacts or premature wear of the mechanical linkage.
How does the sensor pocket length affect the thermal response?
The 75 mm pocket ensures that the sensing bulb is fully immersed in the flow of the medium (such as oil or water). Proper immersion depth is critical for an accurate reading; if the pocket is too short, the sensor may be influenced by the cooler wall temperature of the pipe rather than the actual medium temperature.
Engineering & Installation Guide
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Differential Adjustment: When setting the differential, remember that the setting scale indicates the "cut-out" temperature on a rising temperature. The "cut-in" temperature will be the setpoint minus the differential. Always verify the actual switching points with a calibrated thermometer during commissioning.
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Sensor Pocket Maintenance: Before inserting the KPS 77 sensor into the 75 mm pocket, apply a thin layer of thermal conductive paste to the bulb. This ensures rapid heat transfer from the process medium to the thermostat bellows, reducing the thermal lag of the system.
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Marine Wiring Standards: When installing in maritime environments, use flexible, flame-retardant cabling and ensure the cable gland is tightened to maintain the enclosure's integrity. For systems subject to extreme vibration, use wire end ferrules and ensure all terminal screws are torqued to the specified limits to prevent intermittent contact failure.