My "Line/Wago" Products experience...

[telectrix]

aren't K9 clamps dog muzzles?

 

[specs]

Any tried k9 clamps by Hylec

Just been looking them up, they look interesting , no stripping or screws they just clamp on to cable. not sure if they will be any good for what I want to use them for but they do look interesting. I am sending off for a free sample to get a closer look.

 

[Andy78]

Didn't some mention k9 clamps this week and they got slated as a fire hazard ?

EDIT: found the thread http://www.electriciansforums.co.uk...al-regulations/79899-kwik-wire-connector.html

 

[specs]

Didn't some mention k9 clamps this week and they got slated as a fire hazard ?

EDIT: found the thread http://www.electriciansforums.co.uk...al-regulations/79899-kwik-wire-connector.html

think I will give them a miss then

 

[LineProducts]

just placed my orders (2), I note that your L324L are from 0.75mm flex size, that's ok for me at the moment as i still have stock of this size. However in the future i feel that 0.05 would be a little cheaper as we only use LED. I could probably run all of the lighting on bell wire. Will you be introducing a 0.05 mm version.

Sorry about the slow reply.
There are some products out there for thinner sections but most are more expensive that the ranges we do. I will do some research and if anything interesting comes up will let you know.

 

[davethsparky]

I have a few questions regarding these line jobbies.

Why do the connectors have to be derated when used as a maintenance free connection? Does this mean that they can't actually be relied on to work at their rated current?

How does a cable tie with writing on it make the enclosure maintainance free? what is special about this cable tie in relation to any other cable tie?

I like the look of the inline 2 port connector, but could you create a simillar thing that has a lug at one end? like a push fit version of the blue/red lugs?

 

[Richard Burns]

I have a few questions regarding these line jobbies.

Why do the connectors have to be derated when used as a maintenance free connection? Does this mean that they can't actually be relied on to work at their rated current?

How does a cable tie with writing on it make the enclosure maintainance free? what is special about this cable tie in relation to any other cable tie?

I like the look of the inline 2 port connector, but could you create a simillar thing that has a lug at one end? like a push fit version of the blue/red lugs?

I forgot I was going to say something on this one.

The testing required for the maintenance free side of things must ensure that the connections do not get above certain temperatures which are lower than for accessible locations, this means that the derating of the connectors ensures that the connections are not subject to thermal stress and so will last long enough to not require maintenance.

Maintenance free junction boxes must have the MF logo and possibly the BS number to which they are compliant. Since the line boxes do not have this marking on the body, in order to meet BS7671 the cable ties have this marking and since the maintenance free requirements are for the enclosure as a whole unit this complies.

 

[davethsparky]

That's ridiculous! why aren't these connectors designed to not require maintainence full stop. This sounds to me like sub-standard parts are being produced. The connectors should be rated such that they don't suffer thermal stress anyway regardless of where they are installed. Does this mean that the connectors are likely to suffer from thermal stress when used in non MF situations and therefore will have a reduced lifespan?
Do we need to oversize the cable to avoid it placing thermal stress on the connector? surely a cable which operates at 70 degrees will still operate at 70 degrees even if the connector is down-rated? For example a line 32 amp connector de-rated to 20 amps but used to join a 1.0mm t+e running at 70 degrees will still get heated to 70degrees won't it?
This just sounds like a bodge it and scarper method of getting over cut price manufacturing.

I still don't understand why a maintenance free enclosure needs to have these special cable ties with writing on it? You use a maintenance free joint in situations where the joint is inaccessible therefore nobody will see it to read the writing?

 

[Andy78]

That's ridiculous! why aren't these connectors designed to not require maintainence full stop. This sounds to me like sub-standard parts are being produced. The connectors should be rated such that they don't suffer thermal stress anyway regardless of where they are installed. Does this mean that the connectors are likely to suffer from thermal stress when used in non MF situations and therefore will have a reduced lifespan?
Do we need to oversize the cable to avoid it placing thermal stress on the connector? surely a cable which operates at 70 degrees will still operate at 70 degrees even if the connector is down-rated? For example a line 32 amp connector de-rated to 20 amps but used to join a 1.0mm t+e running at 70 degrees will still get heated to 70degrees won't it?
This just sounds like a bodge it and scarper method of getting over cut price manufacturing.

I still don't understand why a maintenance free enclosure needs to have these special cable ties with writing on it? You use a maintenance free joint in situations where the joint is inaccessible therefore nobody will see it to read the writing?

They wont suffer a reduced lifespan in normal use, they will gain an extended lifespan by downrating for MF use. Any accessible joint should be subject to periodic inspection and test anyway.

MF markings are required for an inaccessible enclosure by BS7671 526.3(vi), and that is why the tie wraps are there to mark up a LINE enclosure should you be using it for MF purposes.

 

[davethsparky]

Which leads nicely on to the question of what the rated lifespan of the connectors is? It doesn't appear to be on their website anywhere. And what is the lifespan of the downrated connector? I assume it will be unlimited as otherwise it will not be maintenance free? And what about the conductor operating temperature? that hasn't changed so how is the connector going to experience less thermal stress by being downrated? You can still join that 1.0mm t+e in one of these MF joints with the 32A connector downrated to 20A and still working at 70degrees, how has the thermal stress on the connector been reduced by the downrating?


If the joint is inaccessible then who on earth is going to read it? If it is accessible to be read then it is accessible and therefore the label is not necessary as it is not inaccessible. Is it just there to give the rats something to read as they nibble on it?

 

[Andy78]

The lifespan really is a "how long is string" question. You seem well aware of the myriad factors that would affect this, and the decision of what to use is down to the electrician that installs them. Have you ever questioned the lifespan or thermal stress capability of a choc strip connector, a 20A junction box, or an insulated butt crimp ?

The MF logo is required by the regs to prove the enclosure has fulfilled the requirements of BS5377. It is to aid initial selection of the enclosure, or for identification of the enclosure if discovered at a later date.

 

[davethsparky]

So they are making these connectors without a rated lifetime. Then de-rating them for use in a MF situation so as to extend the lifespan, but they cannot tell us what the original lifespan was or what it will extend to when de-rated? How do they know that de-rating it is going to extend the lifespan? Why are they not producing connectors which will stand the test of time?

As far as connectors which already exist go they have bee around for a long time and we can all see from existing installations how they stand the test of time when properly installed.


What will that cable tie achieve though? Looking at the picture of them on the website you can see that the writing has already started to rub off of the cable ties, and that's the stock photo from the website! Really doesn't inspire any confidence in its longevity does it?
If discovered at a later date it is likely to have developed a layer of dust or whatever which will have covered the cable tie, and who is going to know what it all means? "instructions must be followed" isn't going to mean jack to anyone other than an electrician who wouldn't need to be told that anyway.

 

[brman]

So they are making these connectors without a rated lifetime. Then de-rating them for use in a MF situation so as to extend the lifespan, but they cannot tell us what the original lifespan was or what it will extend to when de-rated? How do they know that de-rating it is going to extend the lifespan? Why are they not producing connectors which will stand the test of time?

As far as connectors which already exist go they have bee around for a long time and we can all see from existing installations how they stand the test of time when properly installed.


What will that cable tie achieve though? Looking at the picture of them on the website you can see that the writing has already started to rub off of the cable ties, and that's the stock photo from the website! Really doesn't inspire any confidence in its longevity does it?
If discovered at a later date it is likely to have developed a layer of dust or whatever which will have covered the cable tie, and who is going to know what it all means? "instructions must be followed" isn't going to mean jack to anyone other than an electrician who wouldn't need to be told that anyway.

You do appear to have a bit of a downer on these connectors. Do you ask the same questions about crimps, solder connections etc etc before you use them for MF?
because all types of connectors have basically the same issues........

I don't have direct experience of the testing of these connectors but from my product testing experience I would say the following:

]So they are making these connectors without a rated lifetime. Then de-rating them for use in a MF situation so as to extend the lifespan, but they cannot tell us what the original lifespan was or what it will extend to when de-rated? How do they know that de-rating it is going to extend the lifespan?

They will originally have been designed for an expected lifetime. Then samples will have going through excellerated testing (temperature, humidity and vibration cycling while under maximum rated load probably) to prove that they meet the expected lifetime. I suspect the pass/fail criteria for this testing is the increase in resistance measured. That is for non-mf use.

Then they will have been considered for MF use. To pass the BS standard for MF use they would need to pass more rigorous testing. This will probably be a more extreme test cycle with a lower resistance increase limit to ensure that they will last long enough to be buried in the fabric of the building.
Obviously in the wago/line case (they are both the same spec I think) this additional testing found that the maximum current had to be reduced to meet the BS standard.

Why are they not producing connectors which will stand the test of time?

They are, they will have been proved to meet the requirement at the specified (i.e. derated) current.

As far as connectors which already exist go they have bee around for a long time and we can all see from existing installations how they stand the test of time when properly installed.

yes, badly from my experience :lol:
Nothing is perfect, not even a bit of cable will last for ever so the MF stamp doesn't say it is perfect, just acceptable for a specified lifetime. So what would you use that you think is better? Even crimps and soldering is not guaranteed for ever and I have examples of both failing in use.

What will that cable tie achieve though?

All it achieves is ensuring the electrician that fitted it is meeting the regs. BS5733 and BS7671 (reg 526.3 vi) say that it must be MF marked. Other than that you are right, no-one will see it again so who cares.
I suspect line products introduced them just to get round the "but it isn't MF marked so is it really ok to be used?" type questions from customers.

hth. I should stress I have no connection with line or wago other than as a user of their products so all this is assumptions based on my experience of reliability testing products.

 

[gutterball]

the cable ties are to meet the requirements of having the MF marking and to need a tool to open the joint.

 

[Andy78]

So they are making these connectors without a rated lifetime. Are they ? where did you get this from ? Then de-rating them for use in a MF situation so as to extend the lifespan, but they cannot tell us what the original lifespan was or what it will extend to when de-rated? What's the exact lifespan of any other electrcial connector according to the manufacturer ? How do they know that de-rating it is going to extend the lifespan? Why are they not producing connectors which will stand the test of time?

As far as connectors which already exist go they have bee around for a long time and we can all see from existing installations how they stand the test of time when properly installed. Then if the test of time is the only test you value, we will have to wait and see won't we ? Despite these connectors passing relevant standards before sale, the same as any other connector.


What will that cable tie achieve though? Looking at the picture of them on the website you can see that the writing has already started to rub off of the cable ties, and that's the stock photo from the website! Really doesn't inspire any confidence in its longevity does it?
If discovered at a later date it is likely to have developed a layer of dust or whatever which will have covered the cable tie, and who is going to know what it all means? "instructions must be followed" isn't going to mean jack to anyone other than an electrician who wouldn't need to be told that anyway. This applies to all MF marked enclosures then doesnt it ?

Sure you're not trolling ?