Right now I have a power cable that has positive and neutral conductors, with the shield connected to earth. Would it be worthwhile to upgrade it to a 3-conductor cable (+,neutral,earth) with floating shield?
If so, any tips on budget friendly 3 conductor shielded cable?
Thanks! v
RE: 2 vs 3 conductor power cable, posted on September 21, 2016 at 17:32:16
Posts: 1505 Location: Ontario Joined: March 20, 2006
As long as the shield in your present cable is the equivalent of the proper gauge there should be no difference from safety standpoint. Whether there will be a sound difference is open to debate. If you do go to a 3 wire plus shield, floating the shield does nothing. Grounding the shield at the wall plug end only will allow the shield to actually shield noise without adding anything.
Posts: 17117 Location: Pacific Northwest Joined: August 25, 2002
If you are using an ungrounded power cord that only has live and neutral conductors (without a ground conductor), but features a grounded shield for a component that only requires a 2-conductor ungrounded power cord, adding a ground conductor to a 2-conductor power cord will be pointless. When folks ask if it's a good idea to add a ground wire to a component with a 2-conductor power cord, the answer is always if a manufacturer did not design a component to be used with a 3-conductor power cord, never modify a component in order add a ground conductor.
As for grounding the shield, there is no hard rule as to which end to ground it, or to float the shield at both ends for that matter. Some power cords feature a foil shield that floats at both ends, while others feature a shield that's floated at either the AC plug or the IEC connector end. However, when a component is designed to use an ungrounded 2-conductor power cord, and if the shield is to be connected to ground, it should be connected at the AC plug end, since there is no path to ground at the IEC connector end of a 2-conductor power cord.