Difference between LS and LT - Extractor Fan

[wozza101]

Hello. Was wondering if anyone can help. Just had bathroom done and the fitter installed an inline Osily extractor which, quite frankly, is useless! So I've replaced it with a Manrose MF100T which is far better.

However, the Osily has a N, L and LT connection. The Manrose has a N, L and LS connection (see images). Are LS and LT the same thing (presuming switched live)? From what I found on Google, everything suggests they're probably the same, but I can't find a definite answer.

Thanks for your help!

 

[sparkwright]

LS and LT will be the same thing.

(switch/trigger)

 

[sparkwright]

Be aware someone has used a green and yellow wire as a live wire - which, until recently, wasn't a major problem if it had a brown sleeve over it.

 

[wozza101]

Thanks @sparkwright , really helpful. So am I right in thinking that green/yellow wire should have a brown sleeve on?

 

[sparkwright]

Ideally you should have a new cable, consisting of four wires. The fourth being an earth wire, which gets connected to the supply end, where should be an earth connection. At the fan, the earth wire will be placed into a connector block on it's own, as bathroom fans tend to be plastic and don't actually need an earth connection.

All a bit pointless, it would seem, but that's how it should be done, to satisfy all the rules.

Whether you go to all that trouble...

 

[ebee]

agreed, using a g/y conductor whether sleeved or not must never be used as a live conductor - note live includes both the line (phase) and neutral conductors. l,n,e in a plutop etc stands for line neutral and earth not live neutral and earth. yes it really should be done in 4 core and park the earthwire safely in a connector.

that picture is a prime example of why you must always test before touching, no matter what the colour code/diagrams etc says it is.

 

[wozza101]

Oh dear . A bit disappointing really when you hire an electrician to do a job and they do something like this. Thanks for the feedback.

 

[EFLImpudence]

Until recently - very recently - it was allowed to use the green and yellow insulated wire as a live conductor.
The regulations state that conductors shall be "identified" as to their purpose so it should have been sleeved - although being connected to LS might be considered to identify its purpose sufficiently well.

However - very recently; just now (English, not Scottish) - it has been decided that a green and yellow insulated conductor shall no longer be allowed to be used like this.


It will be decades, if ever, until there are no instances left and this is no longer encountered.

 

[sparkwright]

Until recently - very recently - it was allowed to use the green and yellow insulated wire as a live conductor.
The regulations state that conductors shall be "identified" as to their purpose so it should have been sleeved - although being connected to LS might be considered to identify its purpose sufficiently well.

However - very recently; just now (English, not Scottish) - it has been decided that a green and yellow insulated conductor shall no longer be allowed to be used like this.

Although - even though it being permissible to have an insulated green and yellow core over-sleeved as a live conductor, it was still expected that all accessories (except pendants) should have an earth connection - which is awkward, though not impossible, if someone has already borrowed thje earth core.

 

[EFLImpudence]

Although - even though it being permissible to have an insulated green and yellow core over-sleeved as a live conductor, it was still expected that all accessories (except pendants) should have an earth connection - which is awkward, though not impossible, if someone has already borrowed thje earth core.

"Borrowed" being the operative word.

It can always be reclaimed in the future if required.

All moot now.

 

[sparkwright]

"Borrowed" being the operative word.

It can always be reclaimed in the future if required.

All moot now.

The point I'm making - to use the earth core (over-sleeved) as a live conductor, the chances are you would probably have to run a separate earth wire to the accessory (often ending up in a connector all on its own).

 

[EFLImpudence]

The point I'm making - to use the earth core (over-sleeved) as a live conductor, the chances are you would probably have to run a separate earth wire to the accessory (often ending up in a connector all on its own).

Yes, I realised your point - but it depends what the regulators wanted.

Devil's Advocate:
Do you think having to run a "CPC" to all points in case of future need necessarily prohibits its use for another purpose until then when that use is specifically allowed in other circumstances.

Again; all moot now the regulation has been changed.

 

[RandomGrinch]

Again; all moot now the regulation has been changed.

Out of curiosity...

A lot of incidences of over-sleeving the green/yellow occur in C/H controller/thermostat installs.

I'm thinking of the Nest heatlink in particular (which has a completely enclosed case and proper cable grips) - could it be argued that the wiring regs end at the FCU; the Nest may be free to use over-sleeving to connect to the boiler, as it is purely a portable appliance?

 

[EFLImpudence]

A lot of incidences of over-sleeving the green/yellow occur in C/H controller/thermostat installs.

They do - plumbers.

I'm thinking of the Nest heatlink in particular (which has a completely enclosed case and proper cable grips)

I don't think that is relevant.

- could it be argued that the wiring regs end at the FCU;

I know what you mean; they certainly do end at sockets - but there can be lots of fixed wiring after the FCU; possibly more applicable to flex outlet plates.

the Nest may be free to use over-sleeving to connect to the boiler, as it is purely a portable appliance?

It may - but the new regulation specifically prohibits it.

 

[sparkwright]

Devil's Advocate:
Do you think having to run a "CPC" to all points in case of future need necessarily prohibits its use for another purpose until then when that use is specifically allowed in other circumstances.

No, I interpreted it that you could use use an insulated green and yellow core oversleeved in brown or red, and use either another core in a different colour sleeved with green or yellow, or use a separate earth wire, or cable containing an earth wire of some kind.