For full specification Click Here
Din rail mounted underspeed relays suitable for all kinds of machinery to detect loss of speed and pulse continuity. These units are useful when an output contact is required to alarm on jamming, loss of speed due to blunt cutting tools or as a "stationary" contact to allow the release of machine guards. Applications also include being used as "watchdog" relays.
The input is achieved from either a NAMUR proximity switch, PNP sensor or from a clean contact. Unlike the unit type YWRVL the YWRVL4 does not energise for approximately 8 seconds on the initial connection of the coil voltage, but will energise when the first leading edge of an input is seen. Thereon the operation is "time based" an input will reset the time delay, if an input is not seen within the set time the output relay will de-energise but not latch. Therefore the unit will re-energise if a new leading edge of an input is seen. Removal of the coil voltage, failure of the sensor, or a breakage in the cable between the unit and the PLC or sensor will also cause the output relay to de-energise if in an energised state. Hence the underspeed monitor is fail safe.
Watchdog Relay ywrvl4