How to tighten a 50mm SWA gland with no access to locknut

edexlab · Sep 2, 2018

Hello all I'm doing a Job in France for my company where we are installing SWA for power to our own control panels

The issue is the DB is a new modular Schneider panel with removable sides all busbars switchgear etc is at the front and the access is really limited it's bolted to the floor and has large singles already installed in the top for the supply and therefore can't be moved

The people who specified this job clearly don't know what they're doing and it's been left to me to sort it out and get it done

I can only install cables in a certain area along the back of the top panel to avoid internal fittings but you can only get one arm in, at best it's fingertips on a couple of locknuts and it's not possible to hold a pair of stilsons on locknut and gland at the same time even with two people

It may be possible to undo the top panel chock it up to get hands on but with some cables already in I won't know until I try
plus ceiling height is very low with cables coming off a tray in front of the panel so the bend radius is tight

Due to access hammer and screwdriver isn't possible either

I've already installed a bunch of 20/ 25 and a 32 mm glands and had to cut serrations on one side of the locknut to be able to tighten them from the top side

I'm going to try and do the same for the larger glands

Just wondered if anyone had been in a similarly badly designed situation and tried anything which worked well?

Nigel · Sep 2, 2018

At a guess I would imagine you are using the wrong area to take cables into. Are you 100% sure you have the right area?

edexlab · Sep 2, 2018

There is no other available space the sides could have been glanded into customer says they won't permit this
usually on a DB like this they dedicate an area for cables away from internal busbars etc

A TÜV company is testing this install so it may be they'll snag this job for this very reason, and for the way the contractor has installed his cables which he says isn't a problem as the glands he's used are "anti magnetic"?
I have already discussed this with our project manager and been told to carry on

I think the French contractor who installed the DB didn't care about what we were going to gland into and basicly used this area badly glanding in the singles through separate glands in steel plate !

Making it impossible for me to gland in the same area

I have already had to take 2x 50mm 5 core over the DB above ceiling height then drop down and gland into the plinth at the bottom on lhs to ensure I'll have enough room on top

As I said it's been specc'd by people who don't have experience but nice shiny degree diplomas

sinewove · Sep 2, 2018

edexlab said:
Hello all I'm doing a Job in France for my company where we are installing SWA for power to our own control panels

The issue is the DB is a new modular Schneider panel with removable sides all busbars switchgear etc is at the front and the access is really limited it's bolted to the floor and has large singles already installed in the top for the supply and therefore can't be moved

The people who specified this job clearly don't know what they're doing and it's been left to me to sort it out and get it done

I can only install cables in a certain area along the back of the top panel to avoid internal fittings but you can only get one arm in, at best it's fingertips on a couple of locknuts and it's not possible to hold a pair of stilsons on locknut and gland at the same time even with two people

It may be possible to undo the top panel chock it up to get hands on but with some cables already in I won't know until I try
plus ceiling height is very low with cables coming off a tray in front of the panel so the bend radius is tight

Due to access hammer and screwdriver isn't possible either

I've already installed a bunch of 20/ 25 and a 32 mm glands and had to cut serrations on one side of the locknut to be able to tighten them from the top side

I'm going to try and do the same for the larger glands

Just wondered if anyone had been in a similarly badly designed situation and tried anything which worked well?

Is it possible to fit a large coupling onto the gland and then a bush inside?Just a thought.S.

Des 56 · Sep 2, 2018

Is it possible to gland onto a steel plate external, then rivet that plate to the panel

Devonchris · Sep 2, 2018

You could try drilling the hole for the gland closer to the back so the lock nut is flat against the back so it won't turn. Fit the gland without the cable by screwing down onto lock nut then fit the cable.

westward10 · Sep 2, 2018

If you can tighten from the top side get some large serrated washers and fit them under the lock nut, this should eventually hold the nut whilst you tighten.

Marvo · Sep 2, 2018

I've got a bin full of home made spanners I've adapted or fabricated over many years to tighten awkward access gland nuts. Long tube spanners work well where you slide them over the wires inside the enclosure, also ring spanners bent to weird angles with wide slots cut in them and other tools custom fabricated from scratch.

Some glands are long enough to accomodate an extra nut on top as well as the nut inside in which case you finger tighten inside then fully tighten the last half turn with the nut outside.

As already mentioned you can install the gland first then the cable afterward but usually with larger cables you've got to put the gland on the cable first and work the cable into position so the gland sits straight in the gland plate, then loosen the cable to tighten the gland from the top then finally refit the cable again.

edexlab · Sep 2, 2018

Thanks for replies I've already thought about the above answers as at one point or another I've used the same ideas

Bush will make it harder as it reduces the height a little for the bend radius which is already very tight plus getting to hold the brass bush inside is the same issue as with the locknut

Keeping the locknut near the rear can't be done as there is an overhang ie the lid edge extends to the edge of the panel with 40 mm of internal frame inside, I was looking to see if I could lock against the frame in the same manner , so I might try this on the next cable see how it goes

Steel plate I've already done this on another panel into machine as the cable clamp already fitted meant I couldn't get the cable in, but on this panel I'm very short on space anyway so adding plates reduces the space I've got

Serrated washers work really well but I've asked for some and work are reluctant to buy them I think as they're saying they're difficult to source and lead times etc which is a load of rubbish it just makes them look bad that I'm adding materials to the job ie costs are going up

So I made my own serrations in the locknut which worked well as I have a time limit on the job and couldn't wait any longer

edexlab · Sep 2, 2018

2nd Locknut on top is a good idea not seen that before
Thanks for that
I'll get a couple extra ordered and try it

Yes I've a few fabricated spanners I've used before I've been eyeing up a bit of stainless pipe onsite plus there's a tig welder to add a few bits to grip the flats ie make a tubular wrench with Tommy bar but the issue is it's all at arms length so difficult to get any torque on it

Wilko · Sep 2, 2018

If you just can't get it - gland into trunking perhaps?

JK-Electrical · Sep 2, 2018

You might consider these ....

Piranha Earth Nuts - Discount Electrical - http://www.discount-electrical.co.uk/section.php/109701/1/piranha-earth-nuts

edexlab · Sep 2, 2018

I would have but the other contractor has cabling which prevents this

So with all the usual methods being impracticable I am down to just finding a way of tightening them up in situ

Deleted member 26818 · Sep 2, 2018

Sounds to me that your options are limited to making off into some trunking, then feeding the conductors through the trunking into the panel, or to removing the cables that are blocking access and then replacing them once your cables are installed.

edexlab · Sep 2, 2018

It's a crap job alright
as I said earlier trunking isn't an option as there will be panels either side , and contractor already has cables in situ effectively blocking the rhs ie he has large singles at the rear and at the front leaving a gap in the middle which makes it impossible to install my larger sized cables
I pointed out to the customers engineer that
a) he'd installed in such a way as to make things impossible for me
b) he'd installed singles into steel plate thru separate glands

So I just have a small area at the back into which I have put a 25mm on the LHS coming off tray on right
Contractors singles also on same tray
I have used a small area for 15 small cables crammed together where I can cable tie the inner cores in sheath to panel frame out of the way

I've left the area with a clear drop inside for my larger cables which will approach the panel overhead on tray I've installed

The "Engineers" thought I could put 4 x 50mm5c, 1 x 50mm 4c ,1 x25mm5c, 4 x 16 mm5 c, 17 x 2.5/4.0mm cables from the side with a low ceiling height

I'm confident I can get these cables into the panel now I've added tray at the front , it's just tightening the locknuts is the problem however I'm going to try the method I've already used cutting serrations into the locknut, but with Marvos idea of a second locknut on top to tighten

I'll try and upload pics

Thanks for all your help it's much appreciated