AM2- Clipping cables to tray with P clips?

[ManchesterKirchoff]

This might come across as a really daft question to people who work with cable tray quite often but as part of my AM2, I am to clip FP200 to the tray using:

• P Clip
• Nut
• Washer

I’m just a bit confused about how this should look and which parts should be on the “inside” where the cable runs on the tray and the outside (if that makes sense)?

Just don’t want to drop marks or even fail because I’ve in correctly used P clips as I’d find that quite embarrassing to say the least.

If anyone could please explain how this should look or even any pics I’d be really grateful, AM2’s on Monday and I have enough to worry about as is other than P clips.

 

[ipf]

Not aiming this at any one respondent, but Dave makes a valid point.

AM2 can be daunting for trainees and when this guy posts a question two days prior to his test, the majority of reponses have been arguing over irrelevant details.

Whatever the AM2 spec states is exactly what candidates are expected to do - opinions to the contrary don't matter and deviations from spec may result in a candidate failing that section. Failure rates are high.

With the amount of help given over the last fifteen years or so, can the odd casual remark not be taken with pinch of salt?
I can't see many jumping out of their seats to offer help....or comment, even.

It didn't used to be unusual to use pyro fixed with P clips to tray. Hence the nuts and washers, with brass screws. P clips opened and formed into U clips to fix rows of two or three cables or solid copper band for multi cables, cut, formed and drilled for fixings.

At least this was an effort to explain regarding clipping on tray.

 

[nicebutdim]

With the amount of help given over the last fifteen years or so, can the odd casual remark not be taken with pinch of salt?
I can't see many jumping out of their seats to offer help....or comment, even.

At least this was an effort to explain regarding clipping on tray.

As I stated, the comment wasn't aimed at any particular person and you did go on to provide an explanation. I'm not the forum police and people are free to post as they please, but it was worth pointing out that the guy is heading for his AM2 tomorrow and may well be stressed about it.

I've found it strange having to use P clips in this situation, but there's no reason why it shouldn't be done if called for in a spec.

 

[ipf]

As I stated, the comment wasn't aimed at any particular person and you did go on to provide an explanation. I'm not the forum police and people are free to post as they please, but it was worth pointing out that the guy is heading for his AM2 tomorrow and may well be stressed about it.

I've found it strange having to use P clips in this situation, but there's no reason why it shouldn't be done if called for in a spec.

No problem and nothing aimed at your comments.
Hope he stays cool and passes......and doesn't get a question regarding P clipping.

 

[mainline]

This might come across as a really daft question to people who work with cable tray quite often but as part of my AM2, I am to clip FP200 to the tray using:

• P Clip
• Nut
• Washer

It is bit daft if you have no screws to help fit them all.

It is bit daft if you have no screws to help fit them all.

Screws ? Or did you mean bolts

 

[nicebutdim]

It is bit daft if you have no screws to help fit them all.


Screws ? Or did you mean bolts

Most likely supplied with M4 screws.

 

[ipf]

Screws ? Or did you mean bolts

Screws......as in brass 4mm or 2BA, as used to be used.

I hope you're not talking roofers

 

[brianmoooore]

It is bit daft if you have no screws to help fit them all.


Screws ? Or did you mean bolts

I've never seen a 4mm brass bolt - all have been screws. Bolts have an unthreaded section part way along the shaft, starting from the head.
The only brass bolts I've commonly come across are supplied with clamps for earth rods.

 

[mainline]

I've never seen a 4mm brass bolt - all have been screws. Bolts have an unthreaded section part way along the shaft, starting from the head.
The only brass bolts I've commonly come across are supplied with clamps for earth rods.

M4 x 30mm Hex Bolt Full Thread in solid Brass - DIN 933 - Westfield Fasteners Ltd

M4 x 30mm Hex Bolt Full Thread in solid Brass - DIN 933. Also know as a Set Screw or simply a Bolt. Purchase in box or sachet quantity | Next day Delivery.

www.westfieldfasteners.co.uk

 

[brianmoooore]

M4 x 30mm Hex Bolt Full Thread in solid Brass - DIN 933 - Westfield Fasteners Ltd

M4 x 30mm Hex Bolt Full Thread in solid Brass - DIN 933. Also know as a Set Screw or simply a Bolt. Purchase in box or sachet quantity | Next day Delivery.

www.westfieldfasteners.co.uk

That's a type of screw, not a bolt, as the first line of the description alludes to.

 

[ipf]

What’s wrong with 6mm brass nuts and bolts for banjos?
For me, a bolt doesn’t have a screw driver head. It’s the way you interpret, same as umpteen other items.

 

[nicebutdim]

What’s wrong with 6mm brass nuts and bolts for banjos?
For me, a bolt doesn’t have a screw driver head. It’s the way you interpret, same as umpteen other items.

Don't you go spoiling a potential 3 day argument

 

[ipf]

Don't you go spoiling a potential 3 day argument

OK, I’ll bolt off.
I’m sure MK didn’t know what he was starting.
How’s it gone today by the way, MK?

 

[mainline]

That's a type of screw, not a bolt, as the first line of the description alludes to.

Its actually listed as a bolt
M4 x 30mm Hex Bolt Full Thread in solid Brass - DIN 933



The defining distinction, per Machinery's Handbook is in their intended purpose: Bolts are for the assembly of two unthreaded components, with the aid of a nut. Screws in contrast are used in components which contain their own thread, and the screw may even cut its own internal thread into them. Many threaded fasteners can be described as either screws or bolts, depending on how they are used.

 

[brianmoooore]

A correctly specified bolt used to join two accurately machined components together will allow minimal lateral movement. Substitute a screw, lateral movement can occur and the stresses in the fixing will increase, sometimes to the point of failure.
Hex bolt Full Thread is an oxymoron.

 

[pc1966]

A correctly specified bolt used to join two accurately machined components together will allow minimal lateral movement. Substitute a screw, lateral movement can occur and the stresses in the fixing will increase, sometimes to the point of failure.
Hex bolt Full Thread is an oxymoron.

I always used the definition that a bolt was only part-threaded, while a machine screw was fully threaded.

Normally a bolted fixing is held under compression so the threaded/un-threaded aspect ought not to alter lateral movement. If accurate alignment is needed you could attempt to use the un-threaded portion but really at that point a properly fitted dowel is going to do a much better job.

While it is tenuous to call it "electrical work", you see some microwave parts with dowels fitted as the active part is so small and needs such accurate alignment that typical screw/bolt arrangement is just not good enough. For example:

W-Band Waveguide Straight Sections 75-110GHz

Mi-Wave’s 690 Series flanged waveguide sections & bends are available in standard waveguide sizes from 8 to 500 GHz.

www.miwv.com