What are personal protective grounds?
Personal protective grounding (grounds). Cable connected to de-energized lines and equipment by jumpering and bonding with appropriate clamps, to limit the voltage difference between accessible points at a worksite to safe values if the lines or equipment are accidentally re-energized.
What is a personal ground?
Personal protective grounds go by several names in the industry: “temporary protective grounds,” “ground sets,” “ground clusters,” or just plain “grounds.” Personal protective grounds are used whenever workers perform tasks on electrical power systems that may become reenergized for some reason, possibly by the …
What is the smallest conductor size allowed for temporary protective grounds?
Grounding cables — Grounding cables are responsible for providing a low-impedance path for fault current to flow on a properly grounded circuit. The conductors must be made of multi-stranded copper and can be no smaller than 2 AWG.
What size cable would you expect to find on ASTM grade 3 personal protective grounds?
2/0 cable
If relying on this basic method for ground selection, a crew might select a Grade 3 ground with a 2/0 cable, rated at 27,000 amps.
How do you test personal protective grounds?
Protective grounds should be tested with the use of a high current source and a multi-range voltmeter. All test equipment leads should be clean and tight. Volt-meter connection leads must be attached correctly to minimize reading errors due to the lead and connection resistances as well as induced voltages.
When applying protective grounds What is the first connection should always be?
Always connect to the ground source first and then connect to the conductor or equipment with a live-line tool. OSHA requires the use of a live-line tool to install and remove personal protective grounds. 15.
How often must a personal protective ground cable set be inspected?
1.2. 2 All Temporary Protective Grounds shall be tested prior to initial use. 1.2. 3 All Temporary Protective Grounds shall be tested every two years or when any major component (e.g., clamp, ferrule, or cable) of the assembly is repaired, replaced, or suspect.
How often do personal protective grounds need to be tested?
The majority of electric utilities test ground sets every 12 months.
What two types of grounds are required by OSHA?
Grounding
- System or Service Ground: In this type of ground, a wire called “the neutral conductor” is grounded at the transformer, and again at the service entrance to the building.
- Equipment Ground: This is intended to offer enhanced protection to the workers themselves.
How often should protective grounds be tested?
every two years
3 All Temporary Protective Grounds shall be tested every two years or when any major component (e.g., clamp, ferrule, or cable) of the assembly is repaired, replaced, or suspect.
What are the two types of grounds that are required by OSHA?
Do three wire DC systems require grounding?
(1) All 3-wire DC systems must have their neutral conductor grounded. (2) Two-wire DC systems operating at 50-300 volts between conductors must be grounded.