Crimping 6mm T+E

[sjm]

Hi Guys.

So as the title says I recently had to crimp some 6mm T+E using yellow pre-insulated butt crimps. I have a pair of Engex ratchet crimping pliers, which work very well with red and blue crimps, but when I tried to crimp the 6mm the crimps could be easily pulled from the cable. I eventually (after several attempts) managed to get a firm crimp by using the yellow setting first then using the blue die to about half way, then releasing the jaws from the ratchet.

Has anyone else had this problem? Am I using cheap butt crimps, should I get a better crimping tool?
Any suggestions or advice would be greatly appreciated.

Thanks in advance.
Steve.

 

[Darkwood]

When did you last have your crimper calibrated.... also the tug test is not an indication of a good crimp... it may seem tight but under short circuit when possibly many thousands of amps will flow for a split second that is what decides a good and a bad crimp..... cheap ratchet crimper result in poor crimp....also the quality of the crimps also is to be put into question.
I assume being 6mm it is stranded which is ok for your standard ratchet crimper and butt crimps.

 

[Marvo]

Rather use the uninsulated crimps and heat shrink to insulate if necessary. I find the insulated blue / yellow crimps are hit and miss at best, the uninsulated are much more consistent.

 

[RmBo_0]

I had some blue crimps from screwfix once and they where absolutely dreadful. Got some more from TLC and they where some much better.

 

[MDJ]

Wago do a red 40 amp push in and it can handle a 6mm2, I use them and have a box on the van, no good using them though unless you have a decent enclosure, they are bulky.

 

[bigbaddave]

Good quality crimp in my opinion.. And if you think a crimp is a crimp well your wrong. Bought a batch from screwfix and then a batch a week later (No im not using a lot of crimps but a van is a skip and its easier to buy new then look) and they were totally diffrerant..

 

[Knobhead]

When did you last have your crimper calibrated.... also the tug test is not an indication of a good crimp... it may seem tight but under short circuit when possibly many thousands of amps will flow for a split second that is what decides a good and a bad crimp..... cheap ratchet crimper result in poor crimp....also the quality of the crimps also is to be put into question.
I assume being 6mm it is stranded which is ok for your standard ratchet crimper and butt crimps.

Crimpers calibrated?

Get serious, if you can’t tell by the pressure you apply to the crimper then you’ve no right being an electrician.

All crimp manufacturers are slightly different, do you have a set of crimpers for each crimp size and manufacturer also the cable manufacturers? It’s the only way they could be calibrated.

I want to see someone calibrate a BICC crimper. Sorry DW but due to the mechanics of the crimping tool it's impossible!

 

[Ducksy]

Had the same issue a while ago crimping earth for unused 6mm core in SWA, stupid cheap ratchet crimper of ebay, yellow crimp just slipped strait off....so I stupidly tried the blue size on the crimper and got it stuck, cut the cable back and threw the whole thing in the bin.

Just used the non ratchet type one that came in the assorted lug it box worked fine...but wouldn't use it for live cables.

I like the idea of solder/braze cables then heat shrinking them does anyone here do that ?

 

[Spudnik]

I have recently had this issue, and eventually found that the wall thickness of the metal inside the crimp varies a lot between good quality and cheap crimps. Basically, the diameter was the same on both, but on the cheapies, the wall was thinner, and the crimpers only crimp so far.

From now on, i will only use "SWA" branded crimps, and they work fine.

Also, some ratchet crimpers have an adjustment.

Mine is a star shaped disc which has a screw that can be loosed off, the "star" turned and then screwed tight.

Although, this still didnt work on the cheap crimps.

 

[Jay Sparks]

I have recently had this issue, and eventually found that the wall thickness of the metal inside the crimp varies a lot between good quality and cheap crimps. Basically, the diameter was the same on both, but on the cheapies, the wall was thinner, and the crimpers only crimp so far.

From now on, i will only use "SWA" branded crimps, and they work fine.

Also, some ratchet crimpers have an adjustment.

Mine is a star shaped disc which has a screw that can be loosed off, the "star" turned and then screwed tight.

Although, this still didnt work on the cheap crimps.

I have the same sort of crimpers, with the adjustable "star" shaped thingy!!lol But I always double crimp and not in the same spot!!! this is a common mistake.....I crimp in the middle of the crimp, then at the top of the crimp, this ensure a sound connection. As for tug testing, I used the wago's the other day for the first time and Im not convinced they are maintenance free!!! I tugged them all and most seemed fairly loose.....some even came off after I decent tug..lol But the push fit ones seemed to spin around on the cable????? WTF????

I think they need to test the wago's for a few more years yet, before they can be classed as maintenance free!!. As for the crimpers, the "star" shaped thingy that JASON mentioned can be used to tighten or slacken the pressure of the tool.

 

[Outspoken]

Jason has hit the nail on the head, the quality of the crimp as well as the crimper is key to a decent connection.

SWA crimp terminals are the best quality for the insulated type, in fact even their CT crimps are likely the best quality on the market.

Crimpers, you get what you pay for, it never ceases to amaze me when you see sparks that have spent £30-£40 on a set of decent VDE rated sidecutters or pliers, normally both, and yet object to spending decent money on a decent crimper and get a cheap £10 jobby from B&Q or Maplin.

I use one of THESE for crimping up to 6mm² insulated connectors/terminals and one of THESE for the uninsulated crimps

People often make the mistake of using the ones designed for one type of terminal for both types, and this is always creates a bad termination.

 

[MDJ]

use a pair of pliers haha

 

[Outspoken]

use a pair of pliers haha

Don't forget to bang them hard with the 2Ib club hammer to be sure of a firm crimp though..

 

[ipf]

Use the incisors to cut and the molars to crimp, personally

 

[Knobhead]

I just looked at the spec for the first set of crimpers OS put up.
No specific conductor sizes given for a coloured crimp size, so how much do you crimp a 1.5 compared to a 1mm. Both go in a red crimp.

DW, calibrating a set of crimpers, don’t make me laugh!

 

[ipf]

Get my teeth calibrated every 6 months, it's all about the pain threshold.

 

[Geordie Spark]

Solder and heat shrink and be done with it !!!!

 

[sjm]

Thanks for all the replies guys.
Looks like I'd better get some SWA crimps and a better pair of crimping pliers.

 

[Engineer54]

Think i've said this a few times on here when crimping matters come up,. ...I don't like and never have liked the PVC Butt crimps, the heat shrink pre-insulated butt crimps are not too bad, but i still prefer bare crimping with 2 layers of heat shrink tube cover. One to cover the actual bare metal joint and an overall cover. As everyone has stated it's all very much down to the quality of both the crimps and crimping tool being used as to whether your finished crimp joint is going to be any good or not!!

As for calibrating crimp pliers, Yes it can be done, but only with those crimping tools that have the facility, and they normally come in at around £100+ or more and will be the type, say manufactures and the MOD use. Though maybe now day's the throw away philosophy has taken over!! lol!!

 

[Darkwood]

Hammer and cold chisel works fine for me.... no calibration needed just a good aim ;
)