I don't think changing the voice cable that go to the stationswill help. You say when the system goes down it's just the lines, the sets remain operational since your are receiving a screen message.

You say the system removed works in another location, but do the trunk cards work in other systems after they've been removed?

You might want to try a ferrite bead on the CO cable to shield it from the RF burst caused by the arc.


Marv CCNA, CTUB
TeleMarv Services (Retired)
Providing telecommunication solutions in Ottawa Canada since 1990