Types of current loop sensors

There are three common types of current loop sensors: 2-wire, 3-wire, and 4-wire, so named for the number of wiring connections required for each.  All three operate in the same way, but the wiring diagram varies slightly depending on type.

See the following articles for details of each type:

  • 2-wire (Loop-powered)
  • 3-wire
  • 4-wire