Roping off wires in gear

[iwire]

I can't seem to find any info on the type of knot. We are using a lashing style that utilizes several wraps securing the working end.

I have never see gear that required lashing that did not very clearly spell out in great detail how to lash and knot the ropes.

Do you have the manufacturers instruction manual?

 

[ron]

Here is an example of manufacturers instructions for Schneider SWGR for reference.

http://static.schneider-electric.us...ow Voltage Switchgear/PZ4/80298-002-06_en.pdf

Section 4 page 29
Conductor Restraint for Short-Circuit Current Rating

The knot is on page 30

 

[GoldDigger]

Do you have to login or go through the main page to get to that document?

 

[templdl]

But in general the lashing prescribed by the manufacturer does not include any strain relief function and would not help in the situation you suggest.

Out may not have seen the damage that can be done to MCCBs when the weight of the cable on the lugs is sufficient enough to break the breaker molding. Lashing cable can reduce the flexing as a result of fault current but when the cable is also supported by the enclosure it can significantly reduce the stress from the weight of the cable on the breaker terminations.

 

[captainwireman]

Useful does not equate to conformance with the UL testing lab requirements but nice try!

 

[ron]

Do you have to login or go through the main page to get to that document?

The file is very large. Maybe just Google Schneider PZ4 Conductor Restraint for Short-Circuit Current Rating

 

[SceneryDriver]

Using any other rope other than what is specified by the manufacturer would be a violation and should cause a failed inspection.

I would say the chances of a manufacturer approving a different rope are absolutely zero unless you pay for the testing required to prove they would do the job.

In the Schneider manual posted in this thread, it does say "Wrap conductors using 1/2-inch (13 mm) diameter sisal rope or equivalent." I would argue that a low stretch synthetic rope with better moisture tolerance, and superior life would be at least equivalent, if not better. It would be an AHJ call.



SceneryDriver

 

[captainwireman]

I have never see gear that required lashing that did not very clearly spell out in great detail how to lash and knot the ropes.

Do you have the manufacturers instruction manual?

After reading Ron's info from Schneider mfg. I am going to address this knot application as I feel perhaps a non conformance issue is occurring. The tradesman who was installing the lashing told me it is how he was told to do it which leads me to believe there is a possible lack of understanding here. I am not allowed to go into specific details as to manufacturer as per customers request but in general, I certainly will investigate and acquire the necessary information.

 

[captainwireman]

The lashing and required turns around the conductors is clearly shown on a sticker in the gear but no info on the knot style is shown.

 

[GoldDigger]

The lashing and required turns around the conductors is clearly shown on a sticker in the gear but no info on the knot style is shown.

The most effective knot for a particular purpose will vary with the type of rope, although SD's suggested rope would probably be very close to sisal in terms if knotting characteristics.