Electrical Tuition / Installation Critique Thread.

[Sparky Ninja]

I'm going to post some videos from you tube that are driving me mad.
As a lecturer, I concentrate on delivering material clearly and effectively. I watched a couple of videos last night and I was just getting more and more annoyed with them. Either by content, inaccuracy or simply just bad delivery for the viewer..


I have no personal vendetta with any of the companies/individuals and the opinions I post are my own . Some will be electricians, some will be tutors, even a bit of Chris Kitcher, Tony Cable and Dave Austin might crop up


I'll post a video and keep editing my post with my opinion, but I'll give you guys an opportunity to point some things out first..

Each video I will post with a number (Video 1, Video 2 and so on..) so if you post just put the video number in your post so we don't get completely messy in the thread.


If any of you are the creator of these videos, this is just a bit of fun. Please feel free to use it for your own benefit improving the advise you offer..

The order I post these up will be completely random.

 

[Sparky Ninja]

I'm going to start with this one..

VIDEO 1

[video=youtube;-jr4fvLDoiM]http://www.youtube.com/watch?v=-jr4fvLDoiM&feature=related[/video]​

The description with this video on you tube is as follows:

While it is clear there is much to comprehend about the Impedance of a circuit, beginning with understanding the equation: Zs= Ze + (r1 + r2)

The actual Testing of Zs is much more straight forward than it may seem...

My observations are as follows:

• Clearly the (r1&r2) is incorrect. I would go as far to say this is a SIN for a 'technical college' to put forward. It's not explained at all in the video and isn't put down well in the description.. useless! also picked up by IQ Electrical & Lenny
• No reasoning as to 'why' 80% of the figure should be obtained, nor is there a mention about ambient temperatures?
• There is a socket adaptor plugged in above the socket under test. Now it may or may not be live, however that is bad illustration for a test rig. If that was live and a student left it in, it would be an immediate fail.
• No illustration of the reading obtained, he just blurs it out. Visual media is one of the best tools to deliver material, bloomin well use it!!
• An RCBO is installed. So we would assume he carried out the test on the 'no trip' setting? There is no explanation of the High Loop/No Trip options and when they apply?? Maybe even explaining how a 'no trip' test works?also picked up by IQ Electrical
• Bad interpretation of the calculation. Although it seems daft, saying 'point eight' instead of 'zero point eight' is still bad delivery.
• Most importantly of all.. What is a Zs test? What does it prove? Why is it done? This should be understood before a tester is picked up.also picked up by Lenny

Further observations by IQ Electrical:

• No mention of the 'two lead test method'.
• No mention that on a Ring Final (as could be the case on the rig he has, he doesn't tell us), the reading should be taken at all points and the highest reading taken.
• He has an RCBO, but doesn't introduce the potential max Zs of 1667ohms that now can be considered.

 

[IQ Electrical]

Well before watching, it should state (R1+R2)

 

[Guest123]

Obviously doesn't know the difference between r1, r2, & R1+R2!!


Edit - IQ on the ball too!

 

[IQ Electrical]

It would be nice if he mentioned 2 lead testers and the fact that he needed to use a 'no trip' test because of the RCBO.

Also, he could have mentioned the theoretical max Zs of 1667 Ohms for a 30mA device.

 

[IQ Electrical]

Also, he mentions 'the socket circuit' which in many cases will be a ring, the reading should be taken at each outlet and the highest reading recorded as measured Zs.

 

[Guest123]

It might be me but, I would explain what earth fault loop impedance is, why we measure it and what may (or may not) happen if the reading was higher than the maximum permitted value.

 

[IQ Electrical]

Yes, his video is 2 minutes long, mine would be 20!

 

[Guest123]

Well, if you're going to the trouble of making one, might aswell make it a good un!

 

[Sparky Ninja]

VIDEO 2

[video=youtube;3-XG2erpfqw]http://www.youtube.com/watch?v=3-XG2erpfqw&feature=youtube_gdata_player[/video]​

 

[johnboy6083]

no mention of locking off, or warning label! for vid 2. also the bloke needs more practice at presenting. also the mention of illegal, although part p uses bs7671 as its method of acheiving compliance, and part p is a building reg, and i beleive that that is law.

 

[Mr Mike]

Thank you, widdler, for sharing this video.
Oh for the use of correct terminology. I wounder why the distribution board was not shown.
In the back ground there was a couple of downlighters illuminating the top of the wall cupboards-wonderfull.
Regards
Mike.

 

[Sparky Ninja]

Thank you, widdler, for sharing this video.
Oh for the use of correct terminology. I wounder why the distribution board was not shown.
In the back ground there was a couple of downlighters illuminating the top of the wall cupboards-wonderfull.
Regards
Mike.

That's another video

 

[WDMDL]

Prove, Test, Prove?

The rest of the safe isolation procedure?

Terminology? That was painful!

You need to make certain the circuit is powerless of course

Simon.

 

[gutterball]

I'm thinking English isn't his 1st language.