J
we are changing a control panel. currently there is a marshaling cabinet where all instrument gets connected to (LH side). cabling from that TB strip (RH side) is then brought to the controller.
what we are proposing, is to maintain the existing marshaling TBs, and install another control panel that will be connected to the RH side. as of now, the existing instruments DO NOT have their shield connected at the devices end, but the shield is connected to an instrument ground at the marshaling end.
so far so good.
our proposal, is to leave the new cable's shield, the one between RH side and the new control panel, connected only in our panel, unconnected at the marshaling end.
That way, we avoid any ground loop.
the client's engineer rather wants us to leave unconnected, both end of the new cable. His argument, is that a shield should never be connected at 2 places, to which we agree. but we are indeed dealing with 2 cables, not a continuous one... (and there is no TB for the shield, that we could have used to "create" a continuous cable)
in our case, the way we want to do it, each cable involved, will only have one end connected, leaving the other end unconnected. we explained to the client, that this will prevent any ground loop.
we also believe that having no end of the shield unconnected, could potentially create issues, as there is no way to "dissipate" any noise or garbage that could be picked up by the cable ...
I'm out of arguments for the client...it's common/recommended practice to have your shield connected to one end...not both, not none!
Am I wrong in my conclusion?
what we are proposing, is to maintain the existing marshaling TBs, and install another control panel that will be connected to the RH side. as of now, the existing instruments DO NOT have their shield connected at the devices end, but the shield is connected to an instrument ground at the marshaling end.
so far so good.
our proposal, is to leave the new cable's shield, the one between RH side and the new control panel, connected only in our panel, unconnected at the marshaling end.
That way, we avoid any ground loop.
the client's engineer rather wants us to leave unconnected, both end of the new cable. His argument, is that a shield should never be connected at 2 places, to which we agree. but we are indeed dealing with 2 cables, not a continuous one... (and there is no TB for the shield, that we could have used to "create" a continuous cable)
in our case, the way we want to do it, each cable involved, will only have one end connected, leaving the other end unconnected. we explained to the client, that this will prevent any ground loop.
we also believe that having no end of the shield unconnected, could potentially create issues, as there is no way to "dissipate" any noise or garbage that could be picked up by the cable ...
I'm out of arguments for the client...it's common/recommended practice to have your shield connected to one end...not both, not none!
Am I wrong in my conclusion?