Metal Flex Conduit vs EMT Conduit


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Old 02-21-20, 05:44 AM
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Metal Flex Conduit vs EMT Conduit

Seeing electric installations on this can be confusing to me. Can someone give me the basics on when wire should be in regular conduit vs when flex BX type conduit/cable can be used? Should BX conduit be used in an exterior wall?
 
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Old 02-21-20, 08:10 AM
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Basically EMT in open accessible areas where installation is easy and you want a clean looking install. FMC on tough areas to place EMT. MC cable where circuit needs to be fished due to lack of accessibility. They all have there own installation requirements under the NEC. Regular MC cable can go in an exterior wall as long as it's not subject to getting wet, otherwise it needs to be jacketed MC or listed for wet areas.
 
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Old 02-21-20, 08:19 AM
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Hi, it depends on the installation, What are you trying to accomplish? BX type conduit or (flexible metal conduit ) is for flexibility at motors etc. typically not longer than 6í, metal type can not be used outside, Non metallic flexible conduit must be used.
Geo
 
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Old 02-21-20, 09:49 AM
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The 6' rule on Flexible Metal Conduit (FMC) is if the FMC is being used as the ground. If a ground conductor is run in the circuit the 6' doesn't apply.
 
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Old 02-21-20, 10:44 AM
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Got it! Thanks for that clarification.
Geo
 
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Old 02-21-20, 12:09 PM
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BX is not a conduit. It is a cable.
 
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Old 02-22-20, 09:57 AM
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Non metallic flexible conduit must be used.

Outside I generally always specified Liquidtight Flexible Conduit and liked the type with the copper bonding strip.
 
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Old 02-24-20, 04:30 PM
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BX, AC, MC, MC are all cables that come from the manufacturer as an assembly with wires included. FMC aka "Flex" or "Flexible Metal Conduit" is a raceway that is required to be installed and then wires pulled inside it.
 
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