MICC Cable

[RF Lighting]

Slightly OT, but is there another sort of material used to fill the pots when pyro is used in explosion proof installations such as spray booths etc?

Seem to remember hearing that something else is used? I'm not sure as I don't do explosion proof / petrol work.

 

[tim west]

Another tip, after filling the pot with compound and fitted the seal before crimping it test with a megger in case there are any stray slivers of copper trying to short out the cores, pull the cores lightly to get them dead straight inside the pot.

 

[Pensdown]

Slightly OT, but is there another sort of material used to fill the pots when pyro is used in explosion proof installations such as spray booths etc?

Seem to remember hearing that something else is used? I'm not sure as I don't do explosion proof / petrol work.

I don't remember any special compound but to stop the explosive gases entering boxes/fittings etc the gland thread was about 10mm longer.

Anyone remember the heat shrink seals?

 

[tim west]

When I was being taught at college (ok it was a long time ago) the onus wasn't on stopping explosive gases entering switches/equipment but these were of such a design as to contain any explosion internally (big cast bodied switches etc)

 

[Pensdown]

It's both and you're right, if the gases do get inside and are ignited the primary purpose of those huge cast switches is to contain the explosion.

 

[Lectrician]

Anyone remember the yellow two part pots with integrated seal? You litterally clamped in around the stripped end? They where on trial, and I remember a rep coming into college to demonstate. Never seen them since.

 

[tim west]

I remember when the rotary strippers first came out after having been used to the sardine can opener approach for many years, they took a bit of getting used to at first but once you got the hang of it it certainly speeded things up in my experience having terminated many hundreds of pyros in boiler houses around the place. remember the two screw clamps for crimping? took ages doing up the screws evenly in order to get an even flat crimp (three little indents).

 

[ample]

Another tip, after filling the pot with compound and fitted the seal before crimping it test with a megger in case there are any stray slivers of copper trying to short out the cores, pull the cores lightly to get them dead straight inside the pot.

This is quite often the cause of a core going down to earth. I always use a very thin driver to just push the offending sliver out of the way. This all but eliminates the problem.

 

[Pensdown]

The IR test should be done after the cores have been straightened and the seal has been positioned just above the pot, not after the pot has been filled with compound as tims typo suggests.

 

[tim west]

The IR test should be done after the cores have been straightened and the seal has been positioned just above the pot, not after the pot has been filled with compound as tims typo suggests.

I beg to differ the act of pressing in compound especially if done wrong could push the core over to the sheath, doing it the way i suggested has been extremely successful in making many hundreds of pyros off without failures.
as crimping is difficult to rectify without damage to the pot itis prudent to carry out the test before crimping.
Of course you should have wringed out the pyro after stripping back to make sure all dampness has been removed, but through experience you knew how far back to strip to ensure that the test would pass.
I wasn't giving a thorough guide to making off a pyro just a few tips so parts of what to do may have been missing, if you want to learn how to do it properly Pensdown then there are several good guides you can get hold of from MICC manufacturers.

 

[Adam_151]

One of the problems I have with it is that where I peel the sheath off to the line scored around it, it pulls the sheath outwards a little, meaning that while the end is nice and flat, its 'flared' outwards a little and getting the pot on involves a bit of wrestleing!

Not sure what if anything I'm doing wrong?

 

[Pensdown]

Another tip, after filling the pot with compound and fitted the seal before crimping it test with a megger in case there are any stray slivers of copper trying to short out the cores, pull the cores lightly to get them dead straight inside the pot.

Tim, I'm assuming the slivers you're talking about are at the base of the pot? If so, can you tell me how you remove these after the pot is filled with compound?

 

[Pensdown]

One of the problems I have with it is that where I peel the sheath off to the line scored around it, it pulls the sheath outwards a little, meaning that while the end is nice and flat, its 'flared' outwards a little and getting the pot on involves a bit of wrestleing!

Not sure what if anything I'm doing wrong?

If that happens try running the gland and olive over the end a few times that normally sorts it out. It's better to slightly under score and have it flare out than over score and have it flare in.

 

[tim west]

Tim, I'm assuming the slivers you're talking about are at the base of the pot? If so, can you tell me how you remove these after the pot is filled with compound?

not really as you would or should have checked after screwing the pot on, what i mean is any contaminants getting into the pot when filling better to check before you go the whole hog and crimp the seal in. As I was saying earlier there are good guides you can get from the manufacturers that will show you the correct procedures, but also experience is important, the more ends you make off thge better, faster you become.

 

[Pensdown]

Tim, I'm assuming the slivers you're talking about are at the base of the pot? If so, can you tell me how you remove these after the pot is filled with compound?

not really as you would or should have checked after screwing the pot on, what i mean is any contaminants getting into the pot when filling better to check before you go the whole hog and crimp the seal in.

If you contaminated the pot when you're filling it with compound your doing something badly wrong. And what are you going to do if you get a bad IR reading just before you crimp it up, try and dig the compound out?

As I was saying earlier there are good guides you can get from the manufacturers that will show you the correct procedures, but also experience is important, the more ends you make off thge better, faster you become