2391 question paper help!

[spark 68]

you mention it is forbidden to prform Zs tests from a motor terminal? Is this a regulation in Bs7671?
Not familiar with motors and such as most of my work is domestic and light commercial premises.

It is outside the scope of BS7671, and not covered in GN3, which is why I gave you the heads up.

On the 2391 practical you need to calculate the Zs, that means a dead test, by doing 2X (R1+R2) tests, one on each cable, ie. from DB to starter, and one from Starter to motor, and then add to your Ze.
You end up with something like this: Ze+((R1+R2 supply to starter)+(R1+R2 cable from starter to motor))

Iam only giving you this info. as it is not covered in either the OSG, BS7671 or GN3.

 

[Nik_lamb]

12 Week course all the way for me! much more time to understand and let the info sink in, Also having the 12 weeks gives you plenty of revison time, If there are areas you struggle with you have plenty of time to talk to your teacher and work on weak areas. You want to truly understand what you are learning.