Sprinkler Test Question

[George Stolz]

I must apologize in advance for the horrible way I am about to pose this question: May it torture you as it did me.

My friend just took (and passed) his master's exam, at the tender age of 24. :shock:

He secreted out one question in his head, to put to me, as he couldn't find the answer. Neither could I. My conclusion is that he's remembering the question incorrectly, as it makes absolutely no sense to me. But he claims he spent the remaining time of his test studying the question and trying in vain to find the answer, so the question should be well-recorded in his memory.

Q: A center-pivot sprinkler head has a ground ring (perhaps integral to the head?). What size grounding conductor must be connected to this ring?

A.) Sized according to 80% of the FLC of the motor
B.) Sized according to 90%...
C.) ...100%...
D.) ...125%...

Does this in any way sound remotely familiar to anyone?

1. The idea of jumping to a GEC size from a percentage of an FLC rating of a motor just does not make any sense to me. He said no motor spec's were given in the question, and no conductor sizes were given in the answers.

2. The idea of jumping to a EGC size (if the "ground ring" is an internal component of the sprinkler device) from a FLC doesn't jive with 250.122 either.

Any ideas?

 

[celtic]

I have a garden hose...we all have them here in the Garden State

 

[don_resqcapt19]

675.13....size not less than the supply conductors. I would say 100%.
Don

 

[jtester]

If you are referring to a jumper to a rotating ring, then 675.11 applies. It requires the ground to be sized at 125% of the flc of the largest device + the sum of the others. It is possible that 125% is the answer.

Jim T

 

[charlie b]

I agree with Don - 100%. Please note that 675.11 is talking about the rating of the ground ring (a component of the irrigation device). It is not talking about the conductor attached to the ring.

 

[jtester]

Please note that 675.11 is talking about the rating of the ground ring (a component of the irrigation device).

Good call, I stand corrected on my code reference. I'm not sure that 125% is incorrect though. 675.13 says 100% of the supply conductor size, but the question is based on percentage of flc. Would the supply conductor be sized at 100% of flc or 125%?

Jim T

 

[unimo]

I would say 125%. I bet if you saw the question it is worded like 675.22 (A), and they're simplifying it by omitting remaining motors.
It does refer specifically to "center pivot" also. usually in those tests, the question has specific wording that matches a certain part of the code book.

 

[George Stolz]

8) 8) You guys are the bomb!!! 8) 8)

I had no idea this article even existed!!!

It's gotta be 675.11(A). That's almost word for word what the question sounded like. Nate's gonna flip.

I could have swore I looked up "Irrigation" in the index, I guess I didn't!

Thanks so much Don, Jim, Charlie, and all. 8)

 

[unimo]

Yes that exact question was on my master's test, worded like 675.11 (A),
so it would be 125%. It didn't say center pivot on my test.

 

[George Stolz]

I just called him to tell him, he said he already knew. We had another guy find it on his R.W.

Looks like I need to be looking closer at the back half of the book!

What part of the state you from, Unimo?

 

[unimo]

What part of the state you from, Unimo?

Denver

 

[George Stolz]

I've been seeing more and more Colorado folks here lately, it's good to see.

In case I haven't said so already, welcome to the forum.