IEC regulations - earth power and earth signal separation
IEC regulations - earth power and earth signal separation
(OP)
LS,
We were confronted by a customer that IEC regulations (we don't have an answer about which one) require that distance between power earth (220 VAC) and signal earth (4-20 mA) should be at least 1 meter. Can somebody confirm that this regulation exists, or is there somewhere a misinterpretation.
Thanks,
DYV
We were confronted by a customer that IEC regulations (we don't have an answer about which one) require that distance between power earth (220 VAC) and signal earth (4-20 mA) should be at least 1 meter. Can somebody confirm that this regulation exists, or is there somewhere a misinterpretation.
Thanks,
DYV





RE: IEC regulations - earth power and earth signal separation
RE: IEC regulations - earth power and earth signal separation
NFPA Article 504.30 states that intrinsically safe wiring needs to be separated from non-intrinsically safe wiring by 2" (50 mm). I haven't seen any larger distances defined, so you can use that as a ballpark.
John D
RE: IEC regulations - earth power and earth signal separation
@zappedagain: thanks, and in my case it is even a non-hazardous location.
RE: IEC regulations - earth power and earth signal separation
Back in the real world, using very long wires to reach a single point common ground can cause their own problems during lightning strikes. Metal building can help reduce this effect.
RE: IEC regulations - earth power and earth signal separation
However, that should NOT be confused with or misinterpreted as a requirement to separate/isolate the power & signal grounding systems. It would be unsafe to do so and detrimental to the signals that he is presumably concerned about. Moreover, this would be a code violation in the US -- and I'm pretty sure in IEC-land too.
RE: IEC regulations - earth power and earth signal separation
Hope that helps.
RE: IEC regulations - earth power and earth signal separation
Keith Cress
kcress - http://www.flaminsystems.com