Limit-value switch for temperature, input NiCr-Ni-type K thermocouple 1 Straightforward application Suitable for severe operating conditions Compact construction Limit value freely adjustable by drum scale Anti-tamper seal for drum scale Meet high EMC-requirements Limit-value switches Volt-free output as change over switch contact Open-circuit or closed-circuit variants available Reference junction for temperature compensation integrated Broken-wire monitoring for input signal Operating characteristics displayed by integrated LEDs Flame-inhibiting and self-extinguishing body Suitable thermocouples are available Limit-value switches of series 5 Limit value switches of the series 5 are designed to monitor and process electric measured variables. Working principle: When the actual value of the measuring signal supplied reaches the setpoint, the built-in relay will operate. The switching status of the relay contact may, for instance, be monitored or individually processed by a machine controller. General notes on Type RTK5.. Description RTK5.. The Type RTK5.. is designed for the temperature monitoring Volt-free relay contact, closed-circuit or open-circuit version A volt-free relay contact is provided as a change over switch with NiCr-Ni-type K thermocouples according to EN60584-1. The contact for outputting and further processing. In addition, there is a difference is evaluated between an mV-voltage at the tip of the ther- choice between closed-circuit and open-circuit devices. mocouple and that at the end of the compensating line at the limit- In the case of closed-circuit devices, the output relay is pulled value switch. A correction by the temperature at the limit-value switch up in the normal state of operation with the supply voltage applied. applied by an integral reference junction provides information on the It drops off upon the limit-value being exceeded or if the supply volt- temperature at the thermocouple tip. No external reference sensor is required. For satisfactory working of the device, it is necessary that In the open-circuit variant, the output relay pulls up when the the compensating line be extended to the limit-value switch. Settings limit-value is exceeded with the supply voltage applied. Failure of the of the limit value are made at the short top side of the device by voltage will not result in any switching function below the limit value. means of a drum scale. The scale is graduated in degrees Celsius to suit the specific measuring range. Any value on the drum scale can be selected as the limit value. Monitoring sensor integrity The RTK5.. type series comes equipped with broken-wire monitoring. If either or both wires to the thermocouple should be broken, the relay output will operate, the red LED will light up, and the green

Other Data Series RTK5.. Relay position Type key / variants RTK5..-A RTK5..-A RTK5.. Input range: x = contact closed - = contact open The red LED is illuminated, if the limit value is exceeded R Limit-value switch Input signal TK [Thermocouple NiCr-Ni Typ K Type series 5 Type 5