Mike Dolt Enterprises
Mike Dolt Enterprises
User: M. D., Location: Roanoke, VA.
Asked on: Tuesday, April 5, 2011 at 6:46 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:49 am EDT
Question: Blk , red , white = 4/0 ,.. bare = 2/0 What is the purpose of such a large bare conductor ? Am I not seeing something here??.. Main disconnect is a pole mount 200 amp meter/main combo .. Main feeder to the single family dwelling = pipe underground with 3- 4/0 dual rated USE/ RHW and 1 copper #6 thhn to a big ol'e PVC J-box then changes over to the above mentioned SER cable . The grounding electrode is 3 5/8 x 8' ground rods at the pole.. # 6 thhn loops the 3 of them.???? was the # 6 equipment grounding conductor sized correctly for the feeder????? when does it make sense to have a 2/0 bare conductor ? three phase service I guess , and the bare as a grounded?
Purpose of Large Bare Conductor
The 2/0 bare conductor is likely used as a ground wire. It is not uncommon to use a larger bare conductor than the phase conductors in certain situations, such as when the ground wire is required to carry a significant amount of current. In this case, the 2/0 bare conductor may be sized to handle the maximum fault current that could flow through the grounding system.
Grounding Electrode Conductor Sizing
The #6 THHN conductor used to connect the three 5/8" x 8' ground rods is likely not the correct size. According to the NEC, the grounding electrode conductor (GEC) must be sized based on the size of the overcurrent device protecting the circuit. For a 200-amp main disconnect, the GEC should be at least #2 AWG copper.
When to Have a 2/0 Bare Conductor
In addition to three-phase service, there are other situations where it may make sense to have a 2/0 bare conductor: Lightning protection
A bare conductor can be used as a lightning protection conductor.
Equipment grounding
In certain industrial or commercial applications, a 2/0 bare conductor may be used to provide a low-impedance path for equipment grounding.*
Temporary installations: 2/0 bare conductors are often used in temporary electrical installations, such as at construction sites or festivals. Flag for review