lighting circuit

[robertoj]

Hi guys I have questions .What is the most likely electrical fault?
A fault has occurred on a lighting circuit so that when is is switched on the protective device operates
In my option somewhere is short circuit I'm right? Please any comments

 

[Rockingit]

Switch wire has been wired across L-N. Someone decided to put all the reds together, then all the blacks. Was it you??

 

[robertoj]

No I'm working on assignment and need to answer some questions

 

[robertoj]

And next The mounted pillar drill is running at a reduced speed even when it is not under load conditions
I think it is overload?

 

[Richard Burns]

You are correct on the first one and not correct on the second one. Overload would only occur if the drill were under load and it specifically states that it is not under load, although the gearing, etc. could be providing a lot of friction if it is not lubricated.
Are there any more details on the pillar drill?

 

[robertoj]

No Richard just mounted pillar drill

 

[Richard Burns]

If it were three phase then it could have lost a phase, or if single phase the voltage may be too low from a long circuit or a high resistance joint.
But really without further information it would be impossible to say for sure.

 

[robertoj]

This is just questions paper so don't give me more information

 

[Simonslimline]

No Richard just mounted pillar drill

Its 3 phase, and my answer was it is single phasing. My tutor was happy with this.

 

[Simonslimline]

This is just questions paper so don't give me more information

I am sure the paper says it is a 400v drill.