I'm hugely confused. I'm running a brushed universal motor with a PWM rectified AC supply, so 330V pk (from 240ACrms). I'm looking for a device to protect the output drivers from the voltage spikes caused by the brushes. I think I want a device with a clamping voltage ~350-400V. However the below device has a maximum DC/AC rating way below the quoted clamping voltage. Does anyone understand what these mean? I thought any voltage below 395V would see the MOV as a small capacitance. so why is the max DC voltage rating a mere 200V?
https://docs-emea.rs-online.com/webdocs/126d/0900766b8126db7d.pdf
https://docs-emea.rs-online.com/webdocs/126d/0900766b8126db7d.pdf