Open and Short Circuits
Equipment can fail for two basic reasons: the equipment may not get the proper electrical signal to operate or it fails to operate even though it gets the proper electrical signal.
There are many mechanical types of faults that could cause the equipment to fail or operate improperly. A mechanism could be out of adjustment or jammed, bearings could be seized, linkages could be broken, etc. In many cases, an inspection of the equipment will reveal the cause of the failure.
Electrical faults can generally be categorized into either open circuits or short circuits:
- Open circuits occur when there is a break in the circuitry, preventing current from flowing. This could be a broken wire, loose connection, burned out component, etc.
- Short circuits occur when two or more components, which should be isolated come into contact with one another. For example, the insulation or wiring could decay, causing the conductors to short together or short to ground.
Faults can also be a combination of the above. For example, if a wire was to short to ground, the resulting current flow to ground could cause the wire to melt, causing the wire to open as well as still touching ground.
Using a test instrument, such as a multimeter, will allow you to find the cause of the electrical faults you are experiencing.