Mi cable question

[shputnik]

When installing mi cable it is common practice to use hose clamps, metal clips....but wouldn't the dissimilar metals create electrolysis and induce an objectable voltage?


installing mi cable in the top of an enclosure you would have to use the plate (see image) as opposed to drilling directly into the top of the Ferris metal panel and installing the mi cable connectors?

 

[gadfly56]

When installing mi cable it is common practice to use hose clamps, metal clips....but wouldn't the dissimilar metals create electrolysis and induce an objectable voltage?


installing mi cable in the top of an enclosure you would have to use the plate (see image) as opposed to drilling directly into the top of the Ferris metal panel and installing the mi cable connectors?

I don't think dissimilar metals will cause objectionable current, at least as the NEC deals with. It can cause galvanic corrosion. They do make clips and hangers that have a copper wash on them so that would reduce the problem. I'm sure there are clips, clamps, and hangers with plastic liners for this kind of installation out there some where.

 

[LarryFine]

installing mi cable in the top of an enclosure you would have to use the plate (see image) as opposed to drilling directly into the top of the Ferris metal panel and installing the mi cable connectors?

Ferrous is magnetic.

Ferris is Bueller.

 

[infinity]

When installing mi cable it is common practice to use hose clamps, metal clips....but wouldn't the dissimilar metals create electrolysis and induce an objectable voltage?


installing mi cable in the top of an enclosure you would have to use the plate (see image) as opposed to drilling directly into the top of the Ferris metal panel and installing the mi cable connectors?

You can use an aluminum plate like in your photo or cut slots between the KO's.

 

[shputnik]

I don't think dissimilar metals will cause objectionable current, at least as the NEC deals with. It can cause galvanic corrosion. They do make clips and hangers that have a copper wash on them so that would reduce the problem. I'm sure there are clips, clamps, and hangers with plastic liners for this kind of installation out there some where.

I read an article by e&s grounding solutions.

"Scientists have indexed materials based on the nobilities of the metals. This index is called the “Anodic Index” and provides a Voltage for each material. A voltage differential greater than 0.15 Volts is considered corrosive. Copper has a Anodic Index of 0.35 and steel is 0.85. This is a 0.50 volt differential, and can certainly be a source of galvanic corrosion as the earth will surely act as an electrolyte. But there are other concerns in regards to corrosion beyond simple nobility issues, and that is induced AC currents."

 

[gadfly56]

I read an article by e&s grounding solutions.

"Scientists have indexed materials based on the nobilities of the metals. This index is called the “Anodic Index” and provides a Voltage for each material. A voltage differential greater than 0.15 Volts is considered corrosive. Copper has a Anodic Index of 0.35 and steel is 0.85. This is a 0.50 volt differential, and can certainly be a source of galvanic corrosion as the earth will surely act as an electrolyte. But there are other concerns in regards to corrosion beyond simple nobility issues, and that is induced AC currents."

I believe that is referring to AC currents induced on the copper or steel from current flowing in the conductors inside the MI cable assembly or inside the rigid metallic conduit. Galvanic corrosion is DC only.