warm up lose wire

[tom1]

not done this start to finish befor,

got the insulation boards down and prob putting the wiring down tomorrow.

just need a few pointers

got the main feed in to 35mm back box for the stat, then was planning to run twin and earth to a back box at skirting level and bring the 2 flex from the underfloor heating wires.

the floor probe should that run up along the twin to the thermostate?

and testing, i have the megger 1552, is that all i need,

any pointers would be apreciated thanks

 

[sparkytim]

Hi

I take it this is electric under floor heating then?

The 2 heating circuit wires are normally long enough to reach right up to the thermostat if it not to far away, and yes the Temp sensor wire has to go straight up to the Thermostat.

Yes 1552 is all you need

Measure resistence of circuit L-N when you have got it fitted to prove continuity, instruction sheet should tell you what resistence should be, and megger out L+N to CPC

Must be earth screened heating core OR earthed covering to comply with REGS and RCD protected of course.

 

[green-hornet]

Another tip if the wires are going down tommoro make sure the flooring is laid as soon as you finish to prevent damage.

Test continuity before and after the floor is laid. Make sure the client is shown the test results for the continuity before the floor is laid otherwise they may blame you for any damage to the cables.

 

[tom1]

HiI take it this is electric under floor heating then?

The 2 heating circuit wires are normally long enough to reach right up to the thermostat if it not to far away, and yes the Temp sensor wire has to go straight up to the Thermostat.

it is electric mate,

so the stat will be able to accommodate both flex, if they are long enough to reach the stat.

dose the floor probe need to be in capping or trunking?

 

[tom1]

Another tip if the wires are going down tommoro make sure the flooring is laid as soon as you finish to prevent damage.Test continuity before and after the floor is laid. Make sure the client is shown the test results for the continuity before the floor is laid otherwise they may blame you for any damage to the cables.

yer if the floor cant be laid tommorrow i will not do it,

 

[sparkytim]

It can run with other cores in what ever you have used.

 

[steptoe]

it is electric mate, so the stat will be able to accommodate both flex, if they are long enough to reach the stat.

dose the floor probe need to be in capping or trunking?

usually comes with some small bore flexi conduit to allow it to be replaced if necessary

 

[NozSpark]

I've found the best way to do these type of kit is to use small bore flexi conduit for the stat into a KO box just above skirting (bring in heating cold tail also), then up some trunking or conduit to the stat..

This should make for easier replacement of the stat in future years.

 

[batty]

You will need low resistance meter also to test thermostat wire mft will not get low enough.

 

[tom1]

I've found the best way to do these type of kit is to use small bore flexi conduit for the stat into a KO box just above skirting (bring in heating cold tail also), then up some trunking or conduit to the stat..This should make for easier replacement of the stat in future years.

so condiut from skirting to floor level then trunking up to stat

You will need low resistance meter also to test thermostat wire mft will not get low enough.

can you recomend one mate

 

[NozSpark]

Yep,

flexi from floor to skirting box and then oval or conduit to stat.

and a MFT will do the job quite well... I've used my 1502 on every one I've done.

 

[tom1]

Yep,flexi from floor to skirting box and then oval or conduit to stat.

and a MFT will do the job quite well... I've used my 1502 on every one I've done.

got the 1552 will that do then, says in instructions ues a multi meter set at 200 ohms to test the resistance on the heaters to make sure there is a circuit

it also says do not use a continuity tester to test heaters

 

[NozSpark]

Like I say I've used my 1502 to check all the heating mat's that I've done and it is easily capable of checking the heating element and floor stat

The heating element is usually somewhere between 100ohms and 300ohms,,, but this depends on the size of the mat.

The floor stat is nearly always 16.5kohms (or there abouts) - dependant on the temperature

 

[tom1]

just opened up the stat and its got a watchdog alarm, i take it you wire up while its being tiled and the alarm goes of if you cut it

 

[tom1]

Like I say I've used my 1502 to check all the heating mat's that I've done and it is easily capable of checking the heating element and floor statThe heating element is usually somewhere between 100ohms and 300ohms,,, but this depends on the size of the mat.

The floor stat is nearly always 16.5kohms (or there abouts) - dependant on the temperature

got 2 dsw800 book says 64 ohms

 

[green-hornet]

just opened up the stat and its got a watchdog alarm, i take it you wire up while its being tiled and the alarm goes of if you cut it

This is a very usefull devise, tilers will not be as carefull as you are when installing the wires, any cut/damage should be easy to find if regular checks are done during the tiling stage the watchdog alarm will sound if the circuit goes open ie cut, but I would double check with the tester anyway.

 

[NozSpark]

I did one for someone who bought it with a watchdog alarm..

IMO it's more a DIY thing to sort of test the mat,,

you've got a meter so use that instead.

and like I said, the readings will depend on the size of the mat that you are installing.. check your measurements against what they say in the book..

Test the heater..

While still rolled up in pack

after taping to floor,

and then if you are not tiling the floor, self level over the mat and test again

write down your measurements at all stages and take photo's of the install with a tape measure in if you need to show where there are gaps..

The worst one that I did was fitting a 14m loose wire kit in a 0.9m sq room

 

[tom1]

I did one for someone who bought it with a watchdog alarm..IMO it's more a DIY thing to sort of test the mat,,

you've got a meter so use that instead.

and like I said, the readings will depend on the size of the mat that you are installing.. check your measurements against what they say in the book..

Test the heater..

While still rolled up in pack

after taping to floor,

and then if you are not tiling the floor, self level over the mat and test again

write down your measurements at all stages and take photo's of the install with a tape measure in if you need to show where there are gaps..

The worst one that I did was fitting a 14m loose wire kit in a 0.9m sq room

nice and tight then.

so just loads of testing, continuity with the 1552 should be around 64 ohms

 

[tom1]

got the stuff down now, it warms up and readings match up with the book,

bit annoyed it did not come with any pipe for the floor prob like steps mentioned, ended up useing oval conduit and learnt that they dont do elbows and it does not bend to well,

thanks for all the advise

 

[steptoe]

got the stuff down now, it warms up and readings match up with the book,bit annoyed it did not come with any pipe for the floor prob like steps mentioned, ended up useing oval conduit and learnt that they dont do elbows and it does not bend to well,

thanks for all the advise

and NOZ

its not a must have,

just makes it easier in years to come(if needed) for someone to change stat if need be.