The safety temperature limiter STB 55 is used wherever thermal processes need to be monitored, and the plant switched into a safe condition in case of a fault.
If the permissible temperature limit is reached or if a fault occurs in the monitoring equipment within the permissible temperature range (sensor break or short circuit, failure of a component within the device, fault in the software, failure or impermissible value of the supply voltage, etc.) the STB 55 switches off immediately. The alarm contact is activated, the “ALARM” LED in the front panel and the background lighting of the display light up, and the cause of the alarm appears in the display in plain text. In addition, a 24 VDC signal for external alarm signalling is available.
Benefits & Features
- Certified to EN 61508 SIL2 and EN 14597
- Input from Pt 100 in 3-wire connection, or dual thermocouples type J, K, N and S
- Programmable temperature limit and switching hysteresis
- Basic error <0,5 %, ±2 digits
- Response time 0,5s
- 1 SPDT relay for alarm output
- Memory function for error signalling
- Operator lock (password protection)
- Clips onto top-hat DIN rail
- Convenient 4-key operation