|
|
Ground DetectorHome Electrical Safety Electrical Theory Electrician Practice Exams 2005 NEC Search Term IndexGround DetectorThe ground detector is an instrument which is used to detect conductor insulation resistance to ground. An ohm meter, or a series of lights, can be used to detect the insulation strength of an ungrounded distribution system. Most power distribution systems in use today are of the grounded variety; however, some ungrounded systems still exist.In the ground detector lamp method a set of three lamps connected through transformers to the system is used. To check for grounds, the switch is closed and the brilliance of the lamps is observed. If the lamps are equally bright, no ground exists and all the lamps receive the same voltage. If any one lamp is dark, and the other two lamps are brighter, the phase in which the darkened lamp is in is grounded. In this case, the primary winding of the transformer is shorted to ground and receives no voltage. This may seem like an antiquated method but it works.There are many manufacturers of ground detector instruments. Click HERE to see a list of them from Google.
Use this Google search box if you were unable to find what you seek:
|
|