Query on Relay rating

[cherry2000]

We are planning to use Phoenix SIL 3 rated relay for SIS shutdowns to the motor starters. Now the Phoenix relay shows some figures as "Maximum safe shutdown power" in watts at different voltages.The model no of the relay is PSR-SCP- 24DC/ESP4/2X1/1X2.
Can somebody explain the definition of Max.Safe shutdown power

 

[7anoter4]

Hi cherry2000
I don't know this kind of SIL 3 switch ,but in my opinion the Max. Safe shutdown power is related to the maximum current intensity permitted to be interrupted.
So, if you intent to use it with a solenoid [valve] or switchgear, the coil has, let say, a resistance of 4 ohm and the inductance [L] about 165 miliH the division L/R will be
40 ms.
If no coil is involved the circuit will be resistive, more or less, so this kind of switch
will permit up to 6 A to be shutdown for 24 and 48 V.
The maximum current is limited by the corrosion phenomenon due to arc flash and the metal migration. So the voltage too is important.
The arc is supported by L and reduced by C[capacity].
If the supplied power should be alternative current no solenoid would to be permitted[resistive devices only].
Best regards