[Trainee] Needs help from someone experienced.

[Adam_92]

I have a question on an assignment that I could do with some help

Desribe, for each of the following symptoms, the most likely electrical fault.

A) A fault has occurred on a lighting circuit when the lights are operated the RCBO protecting the circuit operates.

B) The outside lights when the protective device is turned off.

My answers for both are.

A) A line to earth fault on the switch live which is causing the rcbo to trip when the switch is operated

B)The switch line and common have been mixed up which is a polarity fault.

Thanks for any help in advance

 

[The Ghost]

I agree with A but B I struggle to understand the scenario. The outside lights, light up? when the protective device is off?

 

[Deleted member 9648]

I'm struggling with B as well, but if it is as it sounds then the likely cause is a faulty protective device, as the 'switch line and common' are on the load side of the device they should both be dead when the device is off. And mixing up the 'switch line and common' is not a polarity fault, they are same polarity.

 

[Leesparkykent]

A. Line to earth fault
B. Neutral to earth fault

 

[Deleted member 9648]

How will a N-E fault light up outside with the protective device off? I must be missing something in question B!

Edit re-reading this I assume B is a poorly worded way of saying with the mcb off the RCD trips, hence the N-E suggestion....but only an RCBO is mentioned.

 

[Leesparkykent]

How will a N-E fault light up outside with the protective device off? I must be missing something in question B!

I take it as the RCBO operates when the light switch is in the off position.

 

[buzzlightyear]

A) A fault has occurred on a lighting circuit when the lights are operated the RCBO protecting the circuit operates.

answer A

B) The outside lights when the protective device is turned off.

answer ,no current will flow to the switch line .

 

[Des 56]

Quest B is a tough one to solve,I am still on the question bit

 

[buzzlightyear]

The outside lights when the protective device is turned off.

by who?

 

[Deleted member 9648]

I've lost interest anyway.

 

[Pete999]

I have a question on an assignment that I could do with some help

Desribe, for each of the following symptoms, the most likely electrical fault.

A) A fault has occurred on a lighting circuit when the lights are operated the RCBO protecting the circuit operates.

B) The outside lights when the protective device is turned off.

My answers for both are.

A) A line to earth fault on the switch live which is causing the rcbo to trip when the switch is operated

B)The switch line and common have been mixed up which is a polarity fault.

Thanks for any help in advance

A L/E Fault
B outside light on another circuit

 

[Adam_92]

My apologise reading this back it doesn't make sense! Was a late night last night.

A) A fault has occurred on a lighting circuit when the lights are turned on the RCBO protecting the circuit trips

B) The outside lights only turn off when the protective device is turned off.

 

[telectrix]

for B then. the switch is knackered, stuck in closed position, or customer's brats have superglued it.

 

[Richard Burns]

My apologise reading this back it doesn't make sense! Was a late night last night.

A) A fault has occurred on a lighting circuit when the lights are turned on the RCBO protecting the circuit trips

B) The outside lights only turn off when the protective device is turned off.

A: an earth fault on the switched part of the lighting circuit
B: a non operational or missing functional switch

 

[rolyberkin]

Adam , Join the trainee section of this site, you will get some good advice over there, was invaluable to me when a trainee. You can search through some of the questions you will come across and they have probably been answered before.

 

[DPG]

This is the problem when people who create these questions (not the OP, the training provider) don't put enough effort into them to ensure there is enough clear information to work with. Seen quite a few lately where it is one very short sentence with very little info and is nearly impossible to get a 'proper' correct answer.