Chapter 6
Where the current is coming from, were you are standing and where and how is contact to the life conductor made. Are all important details in the process of caution due to that of an electric shock.
Hand to foot can be fatal, because the current is probably passing through the heart and lungs.
The wiring device manufacture is required to provide a safety yellow adhesive label over the GFCI receptacle load terminals, or it may be wrapped around the load wire leads.
"Attention, The load terminals under this label are for feeding additional receptacles. Miswriting can leave this outlet without ground fault protection, Read instructions prior to writing."
When a GFCI receptacle is installed, then only that receptacle is shut off when a ground fault greater than ma occurs.
A GFCI receptacle breaks both the ungrounded 'hot' and the grounded conductors
Nuisance Tripping
A GFCI will trip seemingly for no reason. This could be a leakage in very long runs of cable from a GFCI circuit breaker in a panel to the protected branch- circuit wiring. The maximum one way length is 250ft of 76.2m for the branch circuit.
One major defiantly of these testers is they were not designed to test for a false ground.
A false ground is created when a an installer accidently connects the equipment grounding conductor terminal to the neutral terminal.
A GFCI monitors the current balance between the ungrounded 'hot' and the grounded conductors .
As soon as the current flowing through the 'hot' conductor is in the range 4-6 ma more than the current flowing in the return grounded conductors the GFCI trips.
A wet hand coming in contact with a 120 volts.
Could be deadly. 120ma
GFCI protection is not required for receptacles that are obviously not intended to serve countertops.
Like a clock Or behind a fridge or range
Never ground a system neutral conductor except at the service equipment. A GFCI will be inoperative or trip unnecessarily.
Never connect the neutral conductor of one circuit to the neutral conductor of another circuit.
What about multi-wire branch circuits?
Some AFCI and GFCI devices are listed for use on mulit- wire branch circuits. Others are not. Those that are not listed for use on mulit-wire branch circuits have clear instructions warning "Never share a neutral"
The effect of electric current running through the body depends on the circuit characteristics.
Such as current of frequency. 60 Hz is the worst. Voltage, body contact resistance, internal body resistance, the path of current, duration of current flow, and environmental conditions.
When a GFCI circuit breaker is installed, a ground fault at any point in the circuit would shut off everything supplied by the branch circuit.
The GFCI circuit breakers break only the ungrounded "hot" conductor.
The GFCI is required to be installed in a readily accessible location.
This insures that the devices that provides the GFCI can be safely and checked regularly.
GFCI's are require to be self-testing.
This means that the internal electronic circuitry tests the units for the required protection features. This test occurs several times a minute. If the unit fails, it is required to go into fails mode.
A dry hand coming in contact with a 120 volts
Would cause a little tingle. 1.2ma
