Getting USB cable through cable gland

[DanielRehak]

Hello,

at the moment I face a problem where I need to run USB cable through cable gland similar to picture below. First of all I need the cable to be be according to USB 3.2 Gen1 specification (formerly known as USB 3.0, speed 5 Gbit/sec). I would like to avoid cutting connector off, then passing cable through cable hole and then reattaching connector - as I understand this is not something you can do without professional machines for USB 3.2 Gen1 cable.



USB cable has USB-A male connector from both sides. I have trouble guiding USB-A connector through inner gasket of cable glands - gasket is too small for connector. If I use bigger cable gland with bigger gasket diameter, then the gasket is too big for cable diameter.

I cannot use cable gland with split gasket as well. By split gasket I mean gasket which is split in one section, see image below.



The reason is because I need cable gland to have one particular certification. And cable gland with split gasket which has such a certification does not exist. Cable glands without inner gasket which use filling compound instead all seems to have a similar issue - you cannot get the connector part through the cable gland and at the same part end up with cable diameter bigger than minimum allowed cable diameter.

I also tried finding USB extender via CAT 5E or CAT 6 cable such as this one https://www.amazon.com/Monoprice-Extender-CAT5E-Connection-150ft/dp/B003L14ZTC main issue with this is that there is simply no USB 3.2 Gen1 version that would not be big, high power consumption and expensive. If I found one it would be very simple because crimping CAT5 / 6 cable is something anyone can do with simple tools.

So it appears all roads lead to cutting off USB wire, passing it through cable gland and then resoldering cable ends back together.

Now I would like to ask:

Do you have any tips on how to solve this other than soldering USB cables?
Do you have any experience with soldering USB 3.2 Gen1 cables? I am interested mainly in how to reconnect all the shields so the cable is as robust as it can be to EMC.

Cheers,
Dan

[themadhippy]

use a bigger gland and fill it with silicone or would  a usb  bulkhead connector work?

[squadchannel]

considered these USB integrated circular connectors?
look for it, various companies make similar products.

https://www.amphenolltw.com/product-info/USB/TypeA3.2Gen1/?

[DanielRehak]

I need it to pass ATEX directive. It says the device is safe to use in areas with explosion risk. In this certification it is very good for you to use cable glands which are already ATEX certified by cable glands manufacturer. And I did not manage to find any fillable cable glands which meets following requirements:

1] connetor can be passed through
2] cable diameter >= minimal cable diameter found in datasheet

[DanielRehak]

Yes, we did.

Problem is there does not exist a variant with ATEX certification which support USB 5Gbit/sec.

Amphenol makes only 1 variant which is only USB 2.0 compatible which is too slow for my application.

Otherwise this would have been a perfect solution.

[squadchannel]

hmmm.... necessarily have to use a USB connector to make the connection?
What about using ATEX compliant circular connectors and soldering/crimping the USB connector?
Seems better than cutting and passing a cabe gland.

Or can get a cable and USB connector and make your own. There should be a male female connector for soldering.

[DanielRehak]

hmmm.... necessarily have to use a USB connector to make the connection?
(Attachment Link)

The information must be passed over USB protocol as the device does not support any other bus. Most suited for that is USB cable but I suppose CAT 6 cable could also work.

What about using ATEX compliant circular connectors and soldering/crimping the USB connector?
Seems better than cutting and passing a cabe gland.
(Attachment Link)

You would need to buy a cable with male circular connector. Those cables are never twisted pair and dont have the shielding that USB 3.2 Gen2 cables use. I doubt it would work.

Or can get a cable and USB connector and make your own. There should be a male female connector for soldering.

(Attachment Link)

This would be good but I dont think there are any DIY USB 3.2 Gen1 crimping kits. It appears you need professional tools and machines for that.

[voltsandjolts]

You need to be very careful due to ATEX certification requirements.

Some ATEX rated devices have communication interfaces which are only to be used in a safe area, e.g. for configuration before deployment, or data transfer after deployment.

I suggest you take professional advice from someone with ATEX engineering experience before deploying anything in a potentially explosive atmosphere. Perhaps you have already done that.

Edit:

Beware that it is the combination of gland AND cable which make for a safe entry, with a pressure rated explosion pressure containment. You can't fit a random cable to a certified gland and call it safe. You must abide by gland manufacturer guidelines for cables.

[DanielRehak]

Or can get a cable and USB connector and make your own. There should be a male female connector for soldering.

(Attachment Link)

The picture looks interesting. Maybe the solution will be easier then I first thought. Before I was looking only at USB-C and didnt realize you could crimp USB-A. Do you have any experience with soldering and crimping this? I dont know if there are some crimping pliers for this that can be bought.

[mikeselectricstuff]

Could you stretch the grommet over a USB-C plug? Maybe  with the plastic overmoulding stripped off?

[mikeselectricstuff]

If the plug will fit through the panel hole, maybe talk to a cable assembler about supplying cables with the gland already fitted as part of their assembly process

[DanielRehak]

You need to be very careful due to ATEX certification requirements.

Some ATEX rated devices have communication interfaces which are only to be used in a safe area, e.g. for configuration before deployment, or data transfer after deployment.

OK but I need data transfer even after deployment, so this does not help.

I suggest you take professional advice from someone with ATEX engineering experience before deploying anything in a potentially explosive atmosphere. Perhaps you have already done that.

This is development phase, nothing is deployed. I would go to jail if I deployed any product without ATEX certification into ATEX zones. I have read all the norms and consult with institutions which are responsible for ATEX certification in my country.

[langwadt]

https://buttkereit.co.uk/news/atex-certified-cable-entry

[DanielRehak]

Could you stretch the grommet over a USB-C plug? Maybe  with the plastic overmoulding stripped off?

This can be done but you risk stretching the grommet so much it will no longer seal properly. You would need to find a grommet that fulfills following:

1) maximum cable diameter that can fit inside grommet >= maximum USB connector width
2) minimum cable diameter that can fit inside grommet <= USB cable diameter

And there does not exist anything like that. 

[DanielRehak]

If the plug will fit through the panel hole, maybe talk to a cable assembler about supplying cables with the gland already fitted as part of their assembly process

That is good idea, will try that, thank you!

[voltsandjolts]

https://www.mouser.co.uk/new/amphenol/amphenol-pcd-usbftvx-atex-connectors/?srsltid=AfmBOoqUQ-w8mp_KX6o6PhzyUyE3q222iCnPVpHCnl6VlgkNs_NZb1vu

[DanielRehak]

https://buttkereit.co.uk/news/atex-certified-cable-entry

I know these but their certification is "too weak" to make them usable in our application.

[DanielRehak]

https://www.mouser.co.uk/new/amphenol/amphenol-pcd-usbftvx-atex-connectors/?srsltid=AfmBOoqUQ-w8mp_KX6o6PhzyUyE3q222iCnPVpHCnl6VlgkNs_NZb1vu

Thats USB 2.0, not usable.

[voltsandjolts]

Go fibre? ATEX connector solutions for fibre are commercially available.

[rteodor]

Can you go with PG25 and use certified tube or pipe ?
And/or maybe use USB-A to USB-C adapters of some sort ?

I could pass an USB-C connector on a PG9 gasket but it needs just a few mm for the gland parts. The USB-C connector is about 10mm wide, it should go thru PG13 with ease.

[DanielRehak]

Go fibre? ATEX connector solutions for fibre are commercially available.

Would be good. Do you know of some way to convert USB into optical fiber easily? Would have to be some compact solution.

[DanielRehak]

Can you go with PG25 and use certified tube or pipe ?
And/or maybe use USB-A to USB-C adapters of some sort ?

I could pass an USB-C connector on a PG9 gasket but it needs just a few mm for the gland parts. The USB-C connector is about 10mm wide, it should go thru PG13 with ease.

Unfortunately this solution is not suitable for our solution. Thank you for suggestion though!

[voltsandjolts]

Go fibre? ATEX connector solutions for fibre are commercially available.

Would be good. Do you know of some way to convert USB into optical fiber easily? Would have to be some compact solution.

https://www.lindy.co.uk/usb-c4/200m-fibre-optic-usb-3-0-extender-p9144
...and others

[mikeselectricstuff]

Could you stretch the grommet over a USB-C plug? Maybe  with the plastic overmoulding stripped off?

This can be done but you risk stretching the grommet so much it will no longer seal properly. You would need to find a grommet that fulfills following:

1) maximum cable diameter that can fit inside grommet >= maximum USB connector width
2) minimum cable diameter that can fit inside grommet <= USB cable diameter

And there does not exist anything like that.

Warm it up if necessary. Max specced dia when used in the gland isn't the same as what you can stretch it to when taken out of the gland.

[DanielRehak]

Go fibre? ATEX connector solutions for fibre are commercially available.

Would be good. Do you know of some way to convert USB into optical fiber easily? Would have to be some compact solution.

https://www.lindy.co.uk/usb-c4/200m-fibre-optic-usb-3-0-extender-p9144
...and others

This looks interesting. It is definitely the smallest one i ever saw. But its pretty expensive and mainly it needs 5V 3A power supply which could be solved but would be high effort.

For now I decided to buy USB 3.0 male header and solder it back onto cable after cutting and passing it through cable gland.