xara
Member
- Location
- minneapolis, mn
In what situations is a separately derived system needed? list some examples
separately derived system
- Thread starter xara
- Start date
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chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
System required other than that supplied by utility.
xara
Member
- Location
- minneapolis, mn
such as what? Please give an example of a situation
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
Industrial facility has a 208y/120V system and owner buys a 480V piece of equipment.
...what do you think it is? If 480v, 3 phases system feeds building, and you have 120v lights, how do you supply power to lights?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Are these homework questions?
- Location
- Massachusetts
xara, it seems you want us to do your homework for you. That is not going to happen.
However if you put some effort in by trying to answer these questions yourself and posting those answers the members here will be happy to help you.
- Location
- Illinois
- Occupation
- retired electrician
Start with the definition of that term in Article 100.
Carultch
Senior Member
- Location
- Massachusetts
Think of it as a fancy word for the secondary circuits from a transformer that the customer owns at the facility, instead of the utility's main service transformer for the facility.
What is "separately derived" about a separately derived system is that its voltages relative to ground are isolated from the primary side voltages, and therefore the neutral voltage reference to ground would need to be re-established where a grounded neutral is needed.
I think it is more common to see it the other way around. If industrial equipment is the majority of the KVA, I'd certainly start with a 480V service.
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