[Amps] 3-500z Plate voltage...

[Dennis OConnor]

 If you have one arcing you have one going - probably gassy, though it could be a warped grid... A time delay will not change things...

The 3-500  is used in tens of thousands of amps just like yours without problems...
Now many amps do have a limiter relay for the inrush on the primary line, but that is not for the purpose of delaying HV to the anode - they are protecting the filament and, perhaps, the HV rectifiers...

denny / k8do