Rigid metal conduit (RMC), intermediate metal conduit (IMC) and electrical metallic tubing (EMT) are permitted per 250.118(2), (3) and (4) respectively as an Equipment Grounding Conductor. RMC, IMC and EMT are widely used in secondary power distribution systems, indoors and outdoors.
Does conduit act as a ground?
In some installations using metal conduit, the raceway—the conduit, boxes, and connectors—serve as the ground for the circuit. In this way, the metal raceway acts in place of the grounding wire that is found in NM cable (this is also the main reason why only metal boxes may be used with metal conduit).
Where is EMT conduit not allowed?
EMT shall not be used under the following conditions: Where subject to severe physical damage. For the support of luminaires or other equipment except conduit bodies no larger than the largest trade size of the tubing.
Can flexible conduit be used as a ground?
Flexible metal conduit shall be permitted as an equipment grounding conductor where all of the following conditions are met: … The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less. The size of the conduit does not exceed trade size 11/4.
What is the difference between IMC and EMT conduit?
EMT is commonly used for branch circuit wiring in homes (where the wiring runs are exposed) and in commercial buildings. … In residential wiring, IMC is usually limited to service entrance assemblies and exposed runs to and from exterior service panels. Otherwise, EMT is the standard for household installations.
How many bends are allowed in conduit?
No section of conduit shall contain more than two 90-degree bends, or equivalent between pull points. For conduits with an internal diameter of 2 inches or less, the inside radius of a bend in conduit shall be at least 6 times the internal diameter.
Does outdoor wiring need to be in conduit?
Generally speaking, yes, outdoor wiring needs to be in conduit to protect it from physical damage. Type UF cable needs conduit when exposed, no need for conduit on the buried sections.
What if outlet is not grounded?
Yes, absolutely. Ungrounded outlets increase the chance of: Electrical fire. Without the ground present, errors that occur with your outlet may cause arcing, sparks and electrical charge that can spawn fire along walls, or on nearby furniture and fixtures.
What size conduit do I need for 12 2 wire?
For two 12/2 NM cable, you need at least 1″ conduit (by calculations below) but it’ll still be a difficult pull. For two 12/2 UF, you’ll need at least 1-1/4″ conduit.