Bathroom Fan

2011

Par1 wrote: »

Regardless of anything (other examples are irrelevant)...the wires inside the shower pullcord are electrically linked to 2 appliances therefore not complying with the regulation.

To put this simple a shower pull cord can only be used to isolate the shower- one pullcord one shower. If you adapt any other element into this setup by addition of any other appliance direct or indirect, you are then not complying with regulation 555.1.2 (In my opinion)

You could take that view. I wouldn't.
This would mean that almost every vendor skid in industry does not comply

Here is another way to look at it:

Take a plant with 50 motors that are controlled by a single PLC.
When the PLC logic generates a start request a digital output from the PLC sends 24VDC to the coil of a relay, this in turn energises a contactor causing the corrisponding motor to run. In this example let us assume that the PLC has all 50 motors running.

If I turn off the isolator to the PLC's 24V power supply unit all 50 motors will immediately stop.

Would it be your position that all 50 motors have been isolated by one isolator?

Or would it be more accurate to state that all start signals are no longer present?

Par1

2011 wrote: »

Here is another way to look at it:

Take a plant with 50 motors that are controlled by a single PLC.
When the PLC logic generates a start request a digital output from the PLC sends 24VDC to the coil of a relay, this in turn energises a contactor causing the corrisponding motor to run. In this example let us assume that the PLC has all 50 motors running.

If I turn off the isolator to the PLC's 24V power supply unit all 50 motors will immediately stop.

Would it be your position that all 50 motors have been isolated by one isolator?

Or would it be more accurate to state that all start signals are no longer present?

Again that's irrelevant we are discussing a domestic installation consisting of 1 pullcord, 1 shower and 1 fan = (whatever way you look at it) 1 isolator, 2 appliances

2011

Par1 wrote: »

Again that's irrelevant we are discussing a domestic installation consisting of 1 pullcord, 1 shower and 1 fan = (whatever way you look at it) 1 isolator, 2 appliances

It is not two appliances according to the regulations.

If you accept that the electrical component of the fan is the motor then the regulations (as in ET101:2008) only apply to the motor. According to page 10 of ET101 the definition of "appliance" does not apply to a motor.

Therfore the regulation you quoted does not apply

Sir Arthur Daley

Will the jury reach a verdict tonight or will it be recessed for the night?

2011

ET101 applies to domestic & industrial installations. The rules applied to industrial installations are far more stringent.

Regardless there are plenty of examples that would apply to domestic installations. In this age of home automation many devices in a home for heating, lighting, security, electric gates etc. can all switch off by turning off a single isolator. The more common example is a separate hob and oven connected to a single cooker switch.

Ignoring all of that the fact remains that what we have is a signal interface between the shower isolator and a fan. If this was not permitted there would be many installations that would fail. One example that comes to mind is where a standby generator starts when a switch for a distribution board is operated.

Sir Arthur Daley wrote: »

Will the jury reach a verdict tonight or will it be recessed for the night?

You tell me

Part 2 of ET101:2008 , is "definitions"

Appliance: Any device that utilises electricity for a particular purpose, excluding a luminaire or an independent motor.

Sir Arthur Daley

I mentioned the hob and oven on switch earlier in a reply to mikeyjames, he pointed out that its a common supply to 2 items.
The can of worms we are dealing with is a pull cord switching a supply to the shower and supplying power to a coil on a contactor which is then switching on a fan.
So where is the problem, as you already pointed out if an electrician was to come to service the fan he/she should isolate the power to the fan using the triple pole switch rather than switching off the pull cord for the shower and assume its safe to work on.
You previously mentioned a worker with a careless thinking would be off the job and in that case totally agree.
So is my non practical nonsensical suggestion as its being rated electrically safe and compliant?

mikeyjames9

Sir Arthur Daley wrote: »

I mentioned the hob and oven on switch earlier in a reply to mikeyjames, he pointed out that its a common supply to 2 items.
The can of worms we are dealing with is a pull cord switching a supply to the shower and supplying power to a coil on a contactor which is then switching on a fan.
So where is the problem, as you already pointed out if an electrician was to come to service the fan he/she should isolate the power to the fan using the triple pole switch rather than switching off the pull cord for the shower and assume its safe to work on.
You previously mentioned a worker with a careless thinking would be off the job and in that case totally agree.
So is my non practical nonsensical suggestion as its being rated electrically safe and compliant?

the oven and hob is isolation only using cooker switch


your shower/fan suggestion is isolation of shower and control/switching of a fan using same pull-cord



different ball-game

Sir Arthur Daley

mikeyjames9 wrote: »

the oven and hob is isolation only using cooker switch


your shower/fan suggestion is isolation of shower and control/switching of a fan using same pull-cord



different ball-game

Im agreeing with you on that one, i just want an answer am i suggesting an idea for the op that is electrically compliant or not?

2011

Sir Arthur Daley wrote: »

I mentioned the hob and oven on switch earlier in a reply to mikeyjames, he pointed out that its a common supply to 2 items.

Why would that make a difference?

So is my non practical nonsensical suggestion as its being rated electrically safe and compliant?

In my opinion (for what it is worth) it is safe and compliant as well as being a bonkers

Sir Arthur Daley

2011 wrote: »

Why would that make a difference?

The single switch provides direct power to the 2 appliances, in my case the main shower supply supplies a contactor which has seperate supply so to speak from a lighting circuit. I dont agree that this is against regulation though. One cannot assume the shower pull cord is the main isolation for tha fan also which is has been debated earlier.

In my opinion (for what it is worth) it is safe and compliant as well as being a bonkers

That hurts what about my other suggestion any thought?

2011

mikeyjames9 wrote: »

the oven and hob is isolation only using cooker switch

My point exactly.
One isolator for two appliances.

your shower/fan suggestion is isolation of shower and control/switching of a fan using same pull-cord

Precisely, the shower isolator only isolates one device: the shower
The fact that it provides a control interface with the fan is irrelevant.

2011

Sir Arthur Daley wrote: »

That hurts what about my other suggestion any thought?

Sorry, but when it comes to over engineered expensive impractical solutions I like my current relay best.

I have used this solution with great success (and a large budget) for run feedback signals to control systems in the past.

Sir Arthur Daley

2011 wrote: »

Sorry, but when it comes to over engineered expensive impractical solutions I like my current relay best.

I have used this solution with great success (and a large budget) for run feedback signals to control systems in the past.

We are all going to have our own personal best for the op, my second idea came from stanley cookers where a forced flue motor fan is linked to the range, initially it was an after thought to splice into the ranges electrics to power a fan where an installation had a bad draught.
Only ever wired one of them, never came across a situation where this fan needed fitting since.

Par1

Guys the story is getting twisted and away from the original post. I am commentating on the option of 1 shower pullcord feeding 1 shower and 1 fan (controls irrelevant). Lets state some simple facts.

There is 1 shower pullcord - The Isolator
The shower is an electrical appliance - 1 appliance
The fan is another electrical appliance - 1 appliance

1 appliance + 1 appliance = 2 appliances

The shower isolator is electrically supplying both the shower and the fan as they are both wired into the same terminal on the switched/load side of the switch therefore they are both directly (electrically) linked to the pullcord isolation switch.



The regulation clearly states "Every appliance shall be provided with a SEPARATE isolating switch complying with 537.2 and capable of interrupting the load current "

It is my opinion that the appliances are not separated as they both share a common isolator switch therefore not compiling with regulation 555.1.2 - (Every appliance shall be provided with a SEPARATE isolating switch)

2011

Par1 wrote: »

The regulation clearly states "Every appliance shall be provided with a SEPARATE isolating switch complying with 537.2 and capable of interrupting the load current "

It is my opinion that the appliances are not separated as they both share a common isolator switch therefore not compiling with regulation 555.1.2 - (Every appliance shall be provided with a SEPARATE isolating switch)

See post 64, the fan is not considered an appliance by the ETCI (who wrote the regulations).
Therefore 555.1.2 simply does not apply.

Par1

2011 wrote: »

See post 64, the fan is not considered an appliance by the ETCI (who wrote the regulations).
Therefore 555.1.2 simply does not apply.

I do not agree with post 64 as I do not accept that the only electrical component of the fan is the motor as the fan has a PCB and propeller also which makes it an electrical appliance in my view.
You have mis read that definition and used only a part that suits your opinion. The definition actually states:

Appliance - "Any device that utilises electricity for a particular purpose, excluding a luminaire or an independent motor".

May i inform you that a fan utilises electricity for a particular purpose (ventilation). Also a fan is not an independent motor.

Also the ETCI completion certificates for electrical installations require contractors to list a bathroom fan as a 'fixed appliance' therefore they obviously deem a fan to be an electrical appliance.

2011

I just noticed that you have misunderstood how the fan is wired.

Par1 wrote: »

The shower isolator is electrically supplying both the shower and the fan as they are both wired into the same terminal on the switched/load side of the switch therefore they are both directly (electrically) linked to the pullcord isolation switch.

This is not correct.
The fan is supplied from an entirely different circuit than the shower.

The suggestion is:
The fan is supplied from a 10A RCBO in the distribution board.
The shower is supplied from a 40A RCBO located in the same distribution board.

This is explained in post 55.

It is my opinion that the appliances are not separated as they both share a common isolator switch therefore not compiling with regulation 555.1.2 - (Every appliance shall be provided with a SEPARATE isolating switch)

They do not share a common isolation switch. They would if the fan was fed from the shower isolator, it is not.

Par1

What are you talking about post 55? the original comment was made in post 11 - which we are debating. If we were to just run a new supply then there is no issue. You are just trying to backtrack from the fact that you are wrong about the posts you made in regards to regulations etc...


Please answer 2 questions:

1. Do you believe a fan is an electrical appliance or not?
2. Do you believe 1 shower isolator switch may be used to switch 2 electrical appliances - where the appliances are an electrical shower and an electrical fan?

2011

Par1 wrote: »

What are you talking about post 55?

Post 55 is how I always imagined it wired. When I saw Sir Arthur's post, this is how I read it (it would seem that I was incorrect). I see now that his intention (in post 11) may have been different. It is not entirely clear from that post.

Either way I was never a fan of the idea (pun intended ), my first comment on this suggestion states this clearly (post 21) and you agreed with my post.

the original comment was made in post 11 - which we are debating. If we were to just run a new supply then there is no issue.

I am glad we agree on that

You are just trying to backtrack from the fact that you are wrong about the posts you made in regards to regulations etc...

No, I am far too old for that.

I have wrong before and I am wrong now for not looking closer at post 11 and realising that perhaps the intention was to supply both from the same circuit.

In my defence I did state that the extra load on the shower circuit would only be the load of the contractor coil (3W) and I did clearly spell out the circuit arrangement. I also described it as a "signal interface".

Your remarks about prospective short circuit current completely threw me

Please answer 2 questions:

Sure why not?

1. Do you believe a fan is an electrical appliance or not?

My honest answer: In normal everyday life I would regard a fan as an electrical appliance.

However that it does not align with the definition that the ETCI provide.
Connect power to the fan and it will run "independently". It is an independent motor. I can't change the fact that as far as the regulations are concerned it is not an appliance.

Yes it may have a PCB, but this is a component part of the motor. Yes it has a purpose, but all motors do, if not we would not install them. Yes it has a propellor, but the function of all motors is to drive something and the propellor is not an electrical device.

2. Do you believe 1 shower isolator switch may be used to switch 2 electrical appliances - where the appliances are an electrical shower and an electrical fan?

I would not do it, I do not like it but I can not see any danger whatsoever (assuming all cables are sized correctly and have suitable protective devices).

Would it comply with the regulations? Hard to say. If I was a betting man I would say it does, but I admit I would not be 100% confident.

Would I recommend that someone do this? No, I can't see the point.

As I said very early in this thread:

1) Feed a fan with an overrun timer from the light switch
2) Buy a quality humidity sensor and feed the fan from it.

Par1

Cheers for reply 2011, i think we have enlightened people with our comments/debates and hopefully people have taken advise from it as yourself, myself and others have given a lot of good info. At this stage i think the thread is exhausted...like meself!!

I would like to ask you one more question which is and isnt directly related but anyways:

In relation to this debate (especially the later posts!) would you agree that the regulations can be confusing in a way as for every answer there seems to be a contradiction (for most things) if we look hard enough. I personally believe the current regulations are not very clear in some circumstances. I acknowledge that every situation can not be specifically addressed but the regulations in general, could be a lot clearer. I would also be of the opinion that if one regulation contradicts another then it should be clarified.

I appreciate that there would be a cost and that there are amendments but the amendments don't go far enough in my opinion.

I personally don't think the regs will ever change as they are written to give you a guide but never point you to an answer. I believe this is wrong because the electrical industry is regulated but a lot of the rules are unclear i.e ET101 so how is an individual meant to clarify a position if multiple answers exist. Or in some cases - no direct answer

I do admit the tables of values are fairly good though as they have been tested and the results make up the tables.

Finally do you think the regs will ever improve by clarifying more for the electrical contractor?

mikeyjames9

the isolation of 2 "appliances" is not the issue for me

obviously the fan will have it's own isolator anyhow so it's irrelevant


it is the switching/control of a second item using the isolator


i originally envisaged the isolator direct switching the fan which i was unhappy with

but 2011s idea of an isolator providing a "signal interface" makes some sense i suppose

2011

Par1 wrote: »

Cheers for reply 2011, i think we have enlightened people with our comments/debates and hopefully people have taken advise from it as yourself, myself and others have given a lot of good info.

In relation to this debate (especially the later posts!) would you agree that the regulations can be confusing in a way as for every answer there seems to be a contradiction (for most things) if we look hard enough.

There are a few things to consider. The ETCI are a voluntary organisation, so all of the people that sit on their various committees do so for free. When people complain about the cost of their publications I always point to this. In my opinion the intention of ET101 is not to provide a template for every electrical installation or to answer all of the questions that face an electrician or electrical engineer.

Personally I think that ET101 are excellent. Why? When you think about it it is very hard to have a unsafe installation that complies with the fully with the rules. Yet they offer a lot of flexibility to a someone that is designing an electrical installation (I spend most of my time doing this).

According to the ETCI the 4th edition of the rules

..lays down the requirements for the design, erection and proper functioning of electrical installations so as to ensure safety of persons, livestock and property against dangers and damage that may arise in the reasonable use of electrical installations.

I am also very impressed with other work from the ETCI such as ET105 (National Rules for Electrical Installations in Potentially Explosive Atmospheres).

Compared to other countries in general our regulations are miles ahead. I worked in the Netherlands and was truly shocked. In Italy (France and Spain to a lesser extent) in general they just don't believe in earths. I also did some electrical work in Haiti. I can honestly say that my apprentice know far more about voodoo than electrical work. All of the phases and neutral were green and we had no earths at all, what an eye opener!

I personally believe the current regulations are not very clear in some circumstances. I acknowledge that every situation can not be specifically addressed but the regulations in general, could be a lot clearer. I would also be of the opinion that if one regulation contradicts another then it should be clarified.

When writing technical documents being too specific can tie you in knots. If a rule or regulation is very specific and something goes wrong then the designer has a "way out". From the ETCI's perspective it is good to ensure that the person that designs the electrical installation is entirely responsible for the design. So a large installation such as a generating station will comply with ET101 but key decisions have to be made by the design team.

I appreciate that there would be a cost and that there are amendments but the amendments don't go far enough in my opinion.

In general domestic installations are straight forward, there is very little ambiguity. You could say that this thread highlighted that things are not always that clear, but on the other hand we all knew what the sensible solutions were:
1) Feed the fan from the light switch.
2) Fit a quality humidity sensor.
Basically all of the answers are there.

In industrial installations once electrical installation is complex engineers are employed to do the design work, sign off on it and carry the can if anything goes wrong.

I personally don't think the regs will ever change as they are written to give you a guide but never point you to an answer. I believe this is wrong because the electrical industry is regulated but a lot of the rules are unclear i.e ET101 so how is an individual meant to clarify a position if multiple answers exist. Or in some cases - no direct answer

The 3rd edition of ET101 could be used until 30 of september 2009. From that point on the 4th edition had to be used, so they do change.

Finally do you think the regs will ever improve by clarifying more for the electrical contractor?

I think that they will move with the times, but it terms of becoming more specific, I doubt it.

The real issue that I have is not a lack of regulations it is enforcement of the regulations that we have. I have seen inspectors from RECI ignore very clear fundamental regulations to protect their customer (the contractor).

Par1

2011 wrote: »

There are a few things to consider. The ETCI are a voluntary organisation, so all of the people that sit on their various committees do so for free. When people complain about the cost of their publications I always point to this. In my opinion the intention of ET101 is not to provide a template for every electrical installation or to answer all of the questions that face an electrician or electrical engineer.

Personally I think that ET101 are excellent. Why? When you think about it it is very hard to have a unsafe installation that complies with the fully with the rules. Yet they offer a lot of flexibility to a someone that is designing an electrical installation (I spend most of my time doing this).

According to the ETCI the 4th edition of the rules


I am also very impressed with other work from the ETCI such as ET105 (National Rules for Electrical Installations in Potentially Explosive Atmospheres).

Compared to other countries in general our regulations are miles ahead. I worked in the Netherlands and was truly shocked. In Italy (France and Spain to a lesser extent) in general they just don't believe in earths. I also did some electrical work in Haiti. I can honestly say that my apprentice know far more about voodoo than electrical work. All of the phases and neutral were green and we had no earths at all, what an eye opener!



When writing technical documents being too specific can tie you in knots. If a rule or regulation is very specific and something goes wrong then the designer has a "way out". From the ETCI's perspective it is good to ensure that the person that designs the electrical installation is entirely responsible for the design. So a large installation such as a generating station will comply with ET101 but key decisions have to be made by the design team.



In general domestic installations are straight forward, there is very little ambiguity. You could say that this thread highlighted that things are not always that clear, but on the other hand we all knew what the sensible solutions were:
1) Feed the fan from the light switch.
2) Fit a quality humidity sensor.
Basically all of the answers are there.

In industrial installations once jot is anyway complicated engineers are employed to do the design work, sign off on it and carry the can if anything goes wrong.



The 3rd edition of ET101could be used until 30 of september 2009. From that point on the 4th edition had to be used, so they do change.




I think that they will move with the times, but it terms of becoming more specific, I doubt it.

The real issue that I have is not a lack of regulations it is enforcement of the regulations that we have. I have seen inspectors from RECI ignore very clear fundamental regulations to protect their customer (the contractor).

Well worded, great reading and very interesting views, i learned a few new bits from that... thanks for reply.

2011

Thanks