28
STB55
2 Product description
The STB55 safety temperature limiter is used wherever thermal processes must be
monitored and the system must be switched to a safe operating state in case of a
fault. If the permissible temperature limit value is reached or an error occurs in the
monitoring device (probe break, probe short-circuit, failure of a component in the
device, error in the software, failure or impermissible value of the supply voltage,
etc.) within the permissible temperature range, the STB55 switches off immediately.
The alarm contact is confirmed, the front-side ALARM LED and the background
lighting of the display illuminate, and the cause of error is shown on the display in
plain text.
A 24 V DC signal for an external alarm is also connected to terminals 17-18.
2.1 Scope of delivery
•
Safety temperature limiter STB55 with packaging
This operating manual
2.2 Features
•
Can be used as
STB Safety temperature limiter
ASTB Exhaust gas safety temperature limiter
STW Safety temperature monitor
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Certified according to EN 61508 SIL2
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Pt100 input, 3-wire connection or double thermocouple J, K, N and S
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Programmable temperature limit value and switching hysteresis
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Basic accuracy <0.5 %, ±2 digit
•
Reaction time
≤
0.5 s
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Alarm output 1 relay, SPDT
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Pre-alarm output 1 relay, SPDT
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Analog output 0/4 ... 20mA, 0/2 ... 10V
•
Memory function for error message
•
Operator lockout (password-protected)
•
Case for TS35 DIN rail mounting