Electrical code Compliance - NFPA 79 Ground testing

Author

NFPA 79 Ground testing

kstl

2005-09-28, 3:21 pm

Please excuse any improprieties as this is my first post to any
newsgroup.

I just read NFPA 79 19.1 and 19.2,about testing the ground circuit. I
have not done this in the past. How do people usually do this? It seams
the easiest way is to test the impedence but how? I can't use a normal
ohmmeter I assume. Any suggestions as to inexpensive equipment I could
purchase to adaquatly do this test?

Thanks

billb@abc.net

2006-01-28, 7:21 pm

Clause 19.2 sets the following requirements:-
(1) Use an impedance measuring device, take into account any impedance in
the measuring circuit. The measured impedance shall be 0.1 ohm or less.
(2) Apply a current of at least 10 amperes, 50 Hz or 60 Hz, derived from a
SELV source. The tests are to be made between the equipment grounding (PE)
terminal and relevant points that are part of the equipment grounding
(protective bonding) circuit; the measured voltage between the equipment
grounding (PE) terminal and the points of test is not to exceed the values
given in Table 19.2.

To meet these requirements you need a purpose made tester, due to the
requirement for 10A minimum current and 0.1 ohms.
These should be readily available in the USA.

BillB

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