Dick DV did homework THANKS

leitmotif

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This is an offspring to another theread.

I and several others thought that almost all AC electrical systems were required by NEC to be grounded.

I am not referring to equipment enclosures or other non current carrying components of distribution or utilization equipment.

Did my studying and found to not be true.
Art 250 20 says "systems that must be grounded"

1. Systems where any conductor voltage to ground will be 150 or less.
2. 4 wire wye with neutral
3. 4 wire delta where one phase is centertapped.

Thank you Dick for pointing this out and causing me to do homework. Learn every day.

Dan Bentler
 
leitmotif said:
This is an offspring to another theread.

I and several others thought that almost all AC electrical systems were required by NEC to be grounded.

I am not referring to equipment enclosures or other non current carrying components of distribution or utilization equipment.

Did my studying and found to not be true.
Art 250 20 says "systems that must be grounded"

1. Systems where any conductor voltage to ground will be 150 or less.
2. 4 wire wye with neutral
3. 4 wire delta where one phase is centertapped.

Thank you Dick for pointing this out and causing me to do homework. Learn every day.

Dan Bentler
Click to expand...

The NEC requires all systems to have a GROUNDING conductor. The NEC does not require all systems to have a GROUNDED conductor. While the title of 250.20 uses the word grounded, electrically it is describing systems that must be bonded to the grounding system.
 
Jim Dungar said:
The NEC requires all systems to have a GROUNDING conductor. The NEC does not require all systems to have a GROUNDED conductor. While the title of 250.20 uses the word grounded, electrically it is describing systems that must be bonded to the grounding system.
Click to expand...

Jim
I like your wording better. That is what I was trying to say and why I excepted the equipment ground.

Dan
 
thats the problem with the way the code's are written...the difference between a grounded and grounding conductor is huge... we still have lots of 3 phase ungrounded systems here...used primararly in old plants...still see the ground fault lights in lots of older buldings
 

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