bobby ocampo
Senior Member
What do you think is the purpose of Equipment Grounding conductor EGC) for UNGROUNDED SYSTEM? Is it exactly the same as the solidy grounded system?
EQUIPMENT GROUNDING CONDUCTOR FOR UNGROUNDED SYSTEM
- Thread starter bobby ocampo
- Start date
- Status
- Location
- Bremerton, Washington
No. It’s to prevent arcing from induced voltages from lightning. See 250.4
- Location
- Bremerton, Washington
In an ungrounded system a line to ground fault won’t clear. When you get a second line to ground fault then you have a line to line short circuit, which is why GF detection is required
bobby ocampo
Senior Member
What do you mean by prevent arcing from induced voltage from lighting? Can you show us illustration please?
bobby ocampo
Senior Member
What does the EGC accomplish for preventing electric shock if it will not clear the fault?
Will it cause electric shock if there is no EGC in an UNGROUNDED SYSTEM?
Do you mean that in ungrounded system you need two line to ground fault before it will trip the OCPD?
On the first ground fault it will continue to function for UNGROUNDED SYSTEM?
bobby ocampo
Senior Member
What happens to a person touching a metal part of the panel in an UNGROUNDED SYSTEM if one of the current carrying conductor touched the panel and there is no EQUIPMENT GROUNDING CONDUCTOR?
- Location
- Bremerton, Washington
Hold on a bit need to answer your first questions
- Location
- Bremerton, Washington
bobby ocampo
Senior Member
What then does EGC accomplish in preventing shock or electrocution if it will not disconnect the OCPD in a single line to ground fault?
Wil EGC have the same effect in High Resistance Grounded system?
- Location
- Bremerton, Washington
You can think thru the first question yourself.
HRG is not an ungrounded system. Do you understand how an HRG works?
HRG is not an ungrounded system. Do you understand how an HRG works?
- Location
- Illinois
- Occupation
- retired electrician
What hazard is created by a single line to ground fault on an ungrounded system?
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
Section 250.24 (E)
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
What does that have to do with Don's question?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
1. To allow fault detectors to work
2. To allow 2nd faults to clear.
3. To bond all non-current caring metal parts together to reduce touch potential from things like capacitive effects.
4. To connect all non-current caring metal parts to Earth to provide equi-potential during normal operation.
- Location
- Bremerton, Washington
I can later. Too many questions in a short time period
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
In an ungrounded system without a grounding conductor connected to the grounding electrode and connected to a metal enclosure of the service conductors you don't have a low impedance path to trip the breaker. In case of a phase to ground fault.
- Location
- Bremerton, Washington
To the original poster, you would benefit from getting a copy of Mike Holts bonding vs grounding DVD and watching it
- Location
- Bremerton, Washington
The ungrounded system does not have bonding jumper, other than that is the same as a grounded system
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
Correct ... No bonding jumper is required. But an equipment grounding bus is advisable to make the connections easily.
Almost.
It’s line-ground-line. Usually the extra impedance won’t trip overcurrent protection.
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