More Stupid Questions

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erickench

Senior Member
Location
Brooklyn, NY
Alright here's a few more ridiculous questions.

What instruments are required for the proper operation of two or more units in parallel?

A. voltmeter, ammeter and synchroscope
B. wattmeter, power factor meter, and frequency indicator
C. voltage regulator and protective relays
D. multimeter
 

jumper

Senior Member
E. none of the above

I have installed hundreds of lighting units and receptacle units in parallel and never needed any of that stuff for them to operate.

What a POS book! What exactly are "units" ?
 

erickench

Senior Member
Location
Brooklyn, NY
Okay, here's another one:

Which of the following is NOT a factor in the selection of feeder conductor sizes?

A. Load power factor
B. Voltage drop
C. Connected load amperes
D. Branch-circuit protection
 

erickench

Senior Member
Location
Brooklyn, NY
Well a synchroscope is used for that purpose. That's why I would've chosen 'A'. But then again these instruments are meant for monitoring operation and not testing. Maybe 'B' is the answer after all.
 

jeremysterling

Senior Member
Location
Austin, TX
I would have picked "A" on the units in parallel question.

On the second question, there appears to be two non-factors listed, but if I had to pick ONE, I'd toss the branch circuit protection.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Yes the answer key gives 'D' the branch circuit protection as the answer. What I don't understand is how is the load power factor used to size the feeder?
Load power factor affects voltage drop, which they already listed as a choice.
 

erickench

Senior Member
Location
Brooklyn, NY
Here's another:

The insulation resistance of a 100-hp, 440-volt a-c motor is found to be 0.6 megohm. This resistance is

A. satisfactory
B. unsatisfactory
C. borderline
D. unreasonable
 

RichB

Senior Member
Location
Tacoma, Wa
Occupation
Electrician/Electrical Inspector
Well none of them really fit--at least going by how we did it in the Navy back in the 70 and 80s--we used the synchro to bring the units in paralel and then the volt and amp meters to keep the load balanced--which entailed adjusting the frequency via the govenor
 

iaov

Senior Member
Location
Rhinelander WI
The "units" in this question must be alternators. Otherwise the question makes no sense. I personaly have installed thousands of outlets, lights, etc. in paralell and have never seen the need for a syncro-scope, although properly located might just beautify a kitchen install.;)
 
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