Forcibly guided type B
This patented kind of forcibly guided contact realizes a switching construction that fulfills the requirements of SUVA. (Assume: both redundant contacts connected in series in the safety circuit weld simultaneously.) NC 5-6 should generally be used to monitor all 4 NO contacts.
Double contact guarantees high duty ratio
The theoretical increase in contact reliability by the patented double contacts has been verified in practice by this relay’s predecessor, the SFD safety relay. Extremely small total power loss ..
.. is realized if the circuit pathways are properly dimensioned as a result of:
- small coil power loss, due to the polarized magnet system
- small contact resistance, due to a favorable 12R relationship
The 14.5 mm profile ..
.. enables the PC board to have components mounted on both sides, which can then be integrated in slender 22.5 mm safety modules.
Increased isolation according to EN50178
The SFN relay exhibits creepage distance and clearance of 5.5mm and can hence withstand a surge withstand voltage of 6kV, which is required at a switching voltage of 230 / 400V by overvoltage category III and pollution degree 2.