Douglas Krantz - Technical Writer - Describing How It Works
Get the Book
This website uses cookies. See Privacy for details.

What is a Ground Fault?

In a fire alarm system, a Ground Fault is an electrical leakage to ground. When it is installed, the system shouldn't have any ground faults. A ground fault occurs in a building, though, when something changes to the wiring: either from poor installation practices or from damage to the system.

Ground Fault Progression of a wire tied to a threaded rod
Example of a bad installation not showing up as a ground fault until years after being installed. A wire strapped to a threaded rod will only show small marks from the threads after a few days. The insulation will be part way penetrated after months. The insulation will be penetrated all the way through by the threads after years of being compressed by the wire tie. This becomes a ground fault and the ground fault is hard to find if it's above what is now a hard ceiling.


By Douglas Krantz

With the exception of the ground fault circuitry inside the fire alarm control panel (FACP) itself, the wiring for fire alarm systems has no connection to ground. Any connection conducting electricity to ground is causing a ground fault condition.

Ground faults are common; they can and do occur in almost any kind of fire alarm system. For the technician, fixing a ground fault is easy; finding it in the first place is the headache. Sometimes even following the wire is difficult.

Causes

Ground faults are the result of:

Single Ground Fault

Just to be factual, there is no problem with a single ground fault on any fire alarm system. It's just that the technician answering the phone off-site can't tell if it's only a single ground fault, more than one ground fault, or, in the near future, if more ground faults are imminent that will partially impair the system, completely disable the system, or cause false alarms. The ground fault light on the panel just doesn't say.

When to Fix a Ground Fault

Sooner or later, a ground fault has to be fixed. Some technicians might put off troubleshooting until the next business day if there are no other trouble conditions on the panel. However, depending on what causes the ground fault, waiting may be questionable. If any other troubles show on the panel, the troubles, and the ground fault, need to be fixed right away.

Douglas Krantz -- Fire Alarm Engineering Technician, Electronic Designer, Electronic Technician, Writer

See how Class A Wiring works

Share This With Friends:

Go to the Fire Alarm Description Map Page of Douglas Krantzs Technicians Corner
Go to the Residential Life Safety Map Page of Douglas Krantzs Technicians Corner
Go to the Residential Life Safety Map Page of Douglas Krantzs Technicians Corner
Go to the Fire Alarm Description Map Page of Douglas Krantzs Technicians Corner
Go to the General Electrical Map Page of Douglas Krantzs Technicians Corner
Go to the Fire Alarm Maintaining Map Page of Douglas Krantzs Technicians Corner
Go to the Fire Suppression Map Page of Douglas Krantzs Technicians Corner
Go to the Guest Writer's Guidelines of Douglas Krantzs Technicians Corner
See Trivia on Douglas Krantzs Technicians Corner
This website uses cookies. See Privacy for details.
Get the Book
Short Circuit

Uncomplicating Fire Alarm Systems - One Article at a Time

Keep up on the latest article!




No Charge - Unsubscribe Anytime