Test Help

[smileyboy]

Just now getting to my Colorado master Electrician Renewal test.
This question is stumping me.

The grounded conductor of a 277/480 volt 3-phase wye service shall be: (a) isolated from each service disconnecting means. (b) run to and bonded to each service disconnecting means. (c) not larger than 12 ? % of the area of the largest service-entrance phase conductor. (d) sized based on the total circular mil area of the parallel conductors and installed in each parallel raceway.

Can any one help?

 

[chris kennedy]

Whats your guess?

 

[smileyboy]

My guess was C

 

[walkerj]

My guess was C

I believe c) is a trick and reference to the size of the grounding conductor

 

[smileyboy]

Ok thaks,.

On a side note. i can't believe how hard the test is this time. I don't think it took me even 1 hour 2 years ago.

 

[smileyboy]

Ok, I have another one

Each motor-winding connection of a part-winding start induction motor shall have branch-circuit short-circuit and ground-fault protection rated at not more than: (a) 200% for nontime delay fuse. (b) 400% for instantaneous trip breaker. (c) 125% for dual element (time-delay) fuse. (d) 150% for inverse time breaker.

I picked C. But in the code book it says 150% for dual element ..... and there is no option of that one.

 

[JohnJ0906]

Just now getting to my Colorado master Electrician Renewal test.
This question is stumping me.

The grounded conductor of a 277/480 volt 3-phase wye service shall be: (a) isolated from each service disconnecting means. (b) run to and bonded to each service disconnecting means. (c) not larger than 12 ? % of the area of the largest service-entrance phase conductor. (d) sized based on the total circular mil area of the parallel conductors and installed in each parallel raceway.

Can any one help?

B. ............

 

[David C. Adkins]

Ok, I'm waiting, the first answer was b. and the second answer was c.

 

[iwire]

The grounded conductor of a 277/480 volt 3-phase wye service shall be:

(a) isolated from each service disconnecting means.

(b) run to and bonded to each service disconnecting means.

(c) not larger than 12 ? % of the area of the largest service-entrance phase conductor.

(d) sized based on the total circular mil area of the parallel conductors and installed in each parallel raceway.

I go with b.

 

[peter d]

I go with b.

I'll go with "B" as well because Bob's a code genius.

 

[xman1970]

Run to and bonded to each service disconnecting means. 250.24 (C) Good luck with your test.