This is my first time I have encountered a safety relay, and before I get flamed - it is not being used in a safety environment (bear with me...).
Due to an issue with test pulses, a relay is going to be put into a circuit to prevent test pulses from being detected as a true signal. A safety relay has been specified for me, on the basis that the dual contacts will reduce the risk of contact weld.
I have had a quick bench test of a Phoenix safety relay and I may have killed it. It appears that you cannot use external 24V as an input (there is a single input in the circuit, but a dual input is needed at the relay)?
The literature I have reviewed all show volt-free contacts at the stop functions and I can find nowhere that shows an external 24V input into a safety input. Has the role and design of the safety relay been misunderstood, or was my wiring incorrect (I managed to get a squeal and a spark from the relay) or was it a duff relay??
Essentially what I want to do is use a single PLC output (normally 24V, fail 0V) into a 'safety input'. Possible? (apologies for ramble...)
Due to an issue with test pulses, a relay is going to be put into a circuit to prevent test pulses from being detected as a true signal. A safety relay has been specified for me, on the basis that the dual contacts will reduce the risk of contact weld.
I have had a quick bench test of a Phoenix safety relay and I may have killed it. It appears that you cannot use external 24V as an input (there is a single input in the circuit, but a dual input is needed at the relay)?
The literature I have reviewed all show volt-free contacts at the stop functions and I can find nowhere that shows an external 24V input into a safety input. Has the role and design of the safety relay been misunderstood, or was my wiring incorrect (I managed to get a squeal and a spark from the relay) or was it a duff relay??
Essentially what I want to do is use a single PLC output (normally 24V, fail 0V) into a 'safety input'. Possible? (apologies for ramble...)