Conduits, Circuits, & Wiring


Electrical conduit surrounds electrical wiring to protect from impact, moisture and chemical vapors. There are many different kinds and sizes of conduit and it can be used by an electrician for many purposes. Conduit simplifies a wiring installation by providing an unobstructed path for the wiring to run through. Conduit systems can be made waterproof or can protect sensitive circuits from electromagnetic interference.

Special types of conduit can be made to protect wiring from flammable gases and vapors to protect from fire and explosion. Other types of conduit are made to be directly encased in concrete, allowing for specialized installation of outlets and networking/phone ports and ease of running the wires through the floor.

Metal Conduit

  • Rigid Metal Conduit (RMC) - thick threaded tubing, usually made of coated steel
  • Galvanized Rigid Conduit (GRC) - galvanized steel tubing that has walls thick enough to be threaded
  • Intermediate Metal Conduit (IMC) - threadable steel tubing that is lighter than RMC and heavier than EMT
  • Electrical Metallic Tubing (EMT) - commonly used in place of GRC because it is lighter and more cost-effective. EMT is thin walled and cannot be threaded, but can have threaded fitting clamped to it.

Non-Metal Conduit

  • PVC - three wall thicknesses available; thin for embedded use in concrete and heavier grades for burial and exposed work. Various fittings are available
  • Rigid Nonmetallic Conduit (RNMC) - a non-metallic unthreaded tubing

Flexible Conduit

  • Flexible Metallic Conduit (FMC) - AKA greenfield or flex
  • Liquidtight Flexible Metal Conduit (LFMC) - flexible metallic conduit that is covered by a plastic coating that is waterproof.
  • Flexible Metallic Tubing (FMT) - is a raceway NOT a conduit
  • Liquidtight Flexible Nonmetallic Conduit (LFNC) - AKA FNMC flame resistant non-metallic tubing. Interior available smooth or corrugated

Electrical Circuits

Circuits and Wiring

The closed path that a current follows is called an electrical circuit. There three terms commonly used to describe the parts of an electrical circuit, the "source" where the current enters the circuit; the "return" where the current exits the circuit; and the "load" which is the areas between the source and return.

In most cases, electrical circuits use alternating current (AC). Electrical circuit loads can include things as simple as the wiring for a house that included outlet boxes for loads like appliances and electronics; or they can include extremely complex loads for the output of hydroelectric power generating stations.

Wiring Methods

Methods and materials for wiring interior electrical systems differ depending on a variety of factors including:

  • Type, purpose, and size of the building
  • Regulations, both local and national
  • Proposed power demand on circuit

Frequent changes to the wiring systems of light commercial structures are common due to installation of large equipment or the need for specialized systems to handle extreme heat or moisture conditions. Industrial structures often have even more demanding requirements for large currents and high voltage; corrosive, damp, or volatile environments; or frequently changing layout of installed apparatuses. In addition, hazardous areas and conditions may require specialized electrical wiring.

Hartland Electric has the skills, training, and experience to expertly handle all of your conduit, circuit, and electrical wiring needs. Contact us today to discuss all your wiring solutions.