Student begging for advice again...

[Edtwozeronine]

In my design project it's asking me for an example of switching for mechanical maintenance "relating to devices which are not under effective control." What on earth does that mean?

If it's not something you can turn on and off with an isolator switch and lock, what are they talking about?

 

[Bobster]

Is that exactly how the whole question is worded?

 

[Edtwozeronine]

Everything from "switching" to "maintenance" I put in italics what I see as the odd part of the question.

 

[Bobster]

It will be talking about remote isolation, that needs locking off.

E.g. you're not in control of the isolation because the point of isolation is away from your immediate vicinity.

 

[Edtwozeronine]

The second part of the question I've chosen to answer with "A 2 pole enclosed non-fused isolator switch is probably used in the pool and pump equipment area so that one could safely isolate a pump in order to change or clean a water filter." The question being "Switching for mechanical maintenance relating to switching capability."

 

[Edtwozeronine]

I can't think of any examples on the imaginary hotel site where a sparky wouldn't have access to the isolation devices.

 

[Pete999]

In my design project it's asking me for an example of switching for mechanical maintenance "relating to devices which are not under effective control." What on earth does that mean?

If it's not something you can turn on and off with an isolator switch and lock, what are they talking about?

BS7671 Page 155 Regulation 537.3

 

[Bobster]

The second part of the question I've chosen to answer with "A 2 pole enclosed non-fused isolator switch is probably used in the pool and pump equipment area so that one could safely isolate a pump in order to change or clean a water filter." The question being "Switching for mechanical maintenance relating to switching capability."

Off load isolation only...

 

[Edtwozeronine]

Cheers both, i'll have a look around the enormous 7671 yellow pages.

 

[Edtwozeronine]

Off load isolation only...

You mean I'd have to turn off the main switch before the isolation lock off switch?

 

[Bobster]

You mean i'd have to turn off the main switch before the isolation lock off switch?

Most motor isolators when the motor gets to a sufficient size can't make or break the locked rotor current of a motor.

The handles for these should be grey/black, where as isolators capable of making/breaking the full locked rotor current safely should be coloured red/yellow

Edit: If you are currently a trainee, ask one of the mod's on here for access to the trainees lounge.

 

[Pete999]

You mean I'd have to turn off the main switch before the isolation lock off switch?

Depends on the type of switch, whether it can be operated on load, shut the machine down, carry out safe isolation, lock off, carry out maintenance on the machine, job done.

 

[Edtwozeronine]

You seem to have to give too many personal details to get access to the trainees/students lounge.

 

[Pete999]

Cheers both, i'll have a look around the enormous 7671 yellow pages.

No need page 155 says all you need

 

[Bobster]

You seem to have to give too many personal details to get access to the trainees/students lounge.

@Marvo @darkwood @GMES Might be able to look into it for you.