MICC/softskin cable mix

[Rosjes]

Can anyone advise whether or not it would be acceptable to extend an existing, mineral cable FA installation using a soft skin cable such as FP200. The existing building is to be materially altered, most of the devices are to remain, some require moving and others are new. It would seem prudent to make use of what is there and extend in a soft skin.

[Graeme]

depends on what size of building

i.e you might need enhanced

[Rosjes]

Doesn't need to be enhanced Graeme. My query more specifically is whether or not there is guidance why I can't mix cable types.

[Thomas Brookes]

Not as far as Im aware, as long as Graeme said you dont require enhanced.

My only advice would be make sure you fully test all the cables before committing yourself to using it and then put in a clause in your quote that if the cable is found to be unsuitable you can charge extra. With some of the older installations they had panels that did not fault monitor and what often happens (and this is from experience) is that there will be spurs off some devices sharing negs and alsorts of other strange things.
In my very early days I committed to a supposed easy job swapping like for like all the devices and panel in a small hotel. I had been assured the cable had been checked by ADT and was all well. Because I had not been self employed long and very eager to gain new business and basicly needing to pay my mortgage etc I took on this job with out much investigation or testing, just competing on price with the others.
Biggest mistake of my career, I ended up replacing at least 90% of the cable at my expense and the stress involved was a nightmare because the hotel needed to be open.

[Allen Higginson]

Doesn't need to be enhanced Graeme. My query more specifically is whether or not there is guidance why I can't mix cable types.

Unless required to be MICC (by customer policy or the need for enhanced) then it isn't an issue.

[Galeon]

The enhanced business is due to the fire/water spray tests that soft skinned cables did not meet . To my knowledge certain soft skinned cables have now met this , you would have to check with the manufacturer .
There are still some areas that you need to watch on the soft skinned cable side , ie drops to call points need to be mechanically protected is there is a risk to be damaged , obviously the mineral can take a knock.
We had problems in the early days on addressable due to capacitance on mineral , but that has long since gone.
Buzz's comment is spot on as this one usually is not forthcoming , you need to quantify this as a must.
I would factor a sum in because I have seen numerous cross polarities and identify phase tape lost on change overs , additions so be careful when you start breaking in.

[Rosjes]

Thanks all for your input. Will proceed with caution!

[Wiz]

Can anyone advise whether or not it would be acceptable to extend an existing, mineral cable FA installation using a soft skin cable such as FP200. The existing building is to be materially altered, most of the devices are to remain, some require moving and others are new. It would seem prudent to make use of what is there and extend in a soft skin.

The simple answer is yes. As long as both cables meet the fire resistance requirements then BS has nothing to say about mixing cable types.

I concur with the points made by others:

Cable characteristics such as resistance and capacitance can affect the data transmitted in addressable systems. Most panel manufacturers will test using both MICC and soft-skinned fire resistant cables but watch out for moisture affecting these characteristics, especially in MICC.

Any project involving the use of existing cables requires care in checking their condition before use and all of the problems of not knowing if they are already installed correctly and without 'tees' and spurs' (where these would be unacceptable) etc. etc.

'Enhanced' grade cable only needs to be used in those specific situations recommended by BS 5839 part 1 2002.