Safety Timer
What are safety timer /safe time relays?
A safe time relay is a safety-oriented switching device that delays the switching on or off of an output by a defined period of time. It monitors hazardous processes within precise time frames and guarantees a safe state at all times, even in the event of internal defects. The SCB (time relay) is the physical implementation of this concept: an electronic, self-holding safety relay that only releases or stops critical processes after defined times have elapsed. It is typically used in safety-related applications, such as machines with dangerous follow-up movements.
What are the features and functions of safe time relays?
- Flexible switching logic: Depending on the configuration, the safe outputs can be delayed on, delayed off, or instantaneous.
- Precise parameterization: Time ranges from 0 to 99 seconds, minutes, or hours can be easily set using a push-button rotary switch and the integrated display.
- Comprehensive diagnostics: Detailed error messages on the display enable quick troubleshooting and offer the convenience of a modern safety control system.
- Compliance with standards: During modernization, the device ensures that outdated technology is replaced with state-of-the-art components that comply with current standards.
- Easy integration: New variants enable easy integration into existing, classic relay technology thanks to inverted signal outputs.
- Automatic re-triggering: Filtering out short-term fluctuations in limit value monitors effectively prevents unnecessary system downtime.
- Delayed reset: Delayed acknowledgment minimizes the risk of accidental system starts, thereby increasing overall process reliability.
- Safety standards and certifications: The SCB is certified according to EN ISO 13849-1, IEC 61508, EN 50156-1, and EN 746-2 and guarantees maximum fault tolerance thanks to its redundant design.
The safe mini timer SCB replaces obsolete pneumatic time relays
Previously used pneumatic time relays usually no longer meet the state of the art. A standard-compliant protection of the system is therefore no longer possible.
The SCB ensures the current state of the art both in the case of a retrofit and when new burner systems are installed, thus ensuring conformity with the applicable standards.
| Type |
Safety |
Auxilliary |
1 / 2 channel wiring | Width in mm |
Time Rage | Approvals | |
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Safety Timer
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4 | 2 | 1/2 | 22,5 | 0.1 sec - 99 h |  |
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3 | 2 | 1/2 | 22,5 | 0.1 sec - 99 h | |
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2 | 2 | 1/2 | 22,5 | 0.1 sec - 99 h | |
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Compact Safety
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3 | 6 | 1/2 | 45 |
0.1 sec - 990 sec / min / 99h 3 independend times in one TALOS |
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Safety Timer
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4 | - | 1/2 | 22,5 | 0.3 sec - 30 sec |  |
Non safe Timer |
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- | 22,5 | 0.1 sec - 168 h |  |
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22,5 | 0.3 sec - 10 min | |
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45 |
T1: 0.2 - 30 min T2: 0.3 - 20 sec |
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48 | 0.01 sec- 999 h | |
| Type | possible applications | ||||||
Accessories |
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e.g.: ZPower: Mains supply for 230V connection SK3D: Contact amplification galvanic outputs |
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e.g.: Safe contact reinforcement Safe contact duplication |
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e.g.: Safe contact reinforcement Safe contact duplication |
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EKLT4 push-in twin spring connector
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All these variants are available with the following adjustable delay times:
- up to 99 sec
- up to 99 min
- up to 99 h
The SCB-04 is a universally applicable safety timer, with which the moving parts of a machine or plant can be brought to a standstill quickly and safely. Ist has two safe relays contacts and two safe semiconductor outputs.
The SCB-03 has three semiconductor outputs. Depending upon the configuration (programm Pr 00 - Pr 06), the safety outputs connect on-delay, off-delay or without delay independent of one another.
The SCB-02 has two safe relay contacts. A simple and accurate time parametrization is possible with a push/rotary button and the built-in display.
SR4C is a safety relay, which combines the non-delayed and delayed contacts in an extremely compact housing. As a result, dangerous parts of a plant can be switched off quickly and safely during an emergency.
NEW:
New switching function of the auxiliary outputs ease the retrofit
With the new variants of the mini safety timer SCB (e.g. SCB-02-01) you have the possibility to integrate the auxiliary outputs, analogue to the classic relay technique, inverted to the control concept. Especially in the case of a retrofit, it ease the exchange of an old, not state of the art pneumatic time relay.
New function for an automatic re-triggering leads to less system downtime as well as less intervention through the operating personal
The switch-off delay parameterised on the SCB can be used to filter a brief triggering of a limit monitor so that brief triggering of limit monitors, e.g. temperature, pressure or flow rate, must not lead to a switch-off.
New SCB function for a delayed reset signal for preventing accidental confirmations
With the new "delayed resetting" function, the danger of an accidental reset of the safety system can be prevented.
