Armouring for earth

[tigerpaul]

Hello Fellas,

I think I might have dropped a ------- (never a good feeling)
All my SWA cables turned up for a job I'm about to start.
I've got 10mm 2 cores and 4 cores, for SP&N and TP&N DB's
Also 16mm 2 cores and 4 cores, for SP&N and TP%N DB's

Now I'm thinking about whether the armouring will suffice for the earth. I have no information on the design of the job so I'm unaware of any Ze or pfc values.

I know I can always strap a G&Y cpc to the cable later but it looks untidy and I'll have to go back to the gaffer saying I miscalculated on cable (and look like a muppet)

I know I should have got 3 and 5 cores in the first place!

 

[tigerpaul]

Okay I've just found the "sticky" on this subject, and am reading hoping for the best.

Would still appreciate anyones comments though...

 

[Welchyboy]

there is a guide on here i have seen before about values of SWA sheath as a cpc that i stuck in my regs book, and im pretty sure as long as your using PVC/SWA/PVC and not XLPE cable your fine until you start getting into the big boy sizes of around 95mm+

 

[micknew]

Agree with Welchyboy.
We always calculate swa sizes with Amtech software and have never had a failure flagged up for the armour as cpc. We specialise in industrial works in foundry's etc so have done hundreds of calcs for swa's.

 

[Richard Burns]

These are the values I have for the armour copper equivalent csa for
10mm2
2 core PVC 17.7mm2
4 core PVC 20.3mm2
2 core XLPE 8.36 mm2
4 core XLPE 13.5mm2
16mm2
2 core PVC 20.3mm2
4 core PVC 31.9mm2
2 core XLPE 13.5mm2
4 core XLPE 16.0mm2

But might be best to check the cable manufacturers information.

 

[tigerpaul]

Thanks chaps,

It is XLPE cable we're using, only short runs indoors. I'm going to try and get manufacturers details tomorrow and hopefully I'll be alright.

 

[BruceB]

There is a table on the earthingnuts website:
http://www.earthingnuts.co.uk/pdf/pvc_xlpe.pdf

 

[Darkwood]

Shouldnt be a problem at those small sizes but XPLE would need confirming i always use pvc also freindly word of caution Tiger! Watch your P's and Q's its a public forum and the Mods dont appreciate swearing on any level as it lowers the value of the site :38:

 

[Engineer54]

Here you go, The figure in brackets are those cable that DON'T comply!! As you can see your fine all the way up to 95mm, on 2 core SWA cables...



Table for 90[SUP]0[/SUP]C Thermosetting SWA cables operating at 70[SUP]0[/SUP]C.

[TABLE="class: yiv1034213597MsoTableGrid"]
[TR]
[TD="width: 118"]

Conductor CSA​

[/TD]
[TD="width: 118"]

Minimum CSA of SWA to meet 54G​

[/TD]
[TD="width: 118"]

CSA of armour 2 core​

[/TD]
[TD="width: 118"]

CSA of armour 3 core​

[/TD]
[TD="width: 118"]

CSA of armour 4 core
​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

1.5​

[/TD]
[TD="width: 118"]

3.4​

[/TD]
[TD="width: 118"]

16​

[/TD]
[TD="width: 118"]

17​

[/TD]
[TD="width: 118"]

18​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

2.5​

[/TD]
[TD="width: 118"]

5.7​

[/TD]
[TD="width: 118"]

17​

[/TD]
[TD="width: 118"]

19​

[/TD]
[TD="width: 118"]

20​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

4​

[/TD]
[TD="width: 118"]

9.0​

[/TD]
[TD="width: 118"]

19​

[/TD]
[TD="width: 118"]

21​

[/TD]
[TD="width: 118"]

23​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

6​

[/TD]
[TD="width: 118"]

13.6​

[/TD]
[TD="width: 118"]

22​

[/TD]
[TD="width: 118"]

23​

[/TD]
[TD="width: 118"]

36​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

10​

[/TD]
[TD="width: 118"]

22.6​

[/TD]
[TD="width: 118"]

26​

[/TD]
[TD="width: 118"]

39​

[/TD]
[TD="width: 118"]

43​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

16​

[/TD]
[TD="width: 118"]

36.1​

[/TD]
[TD="width: 118"]

41​

[/TD]
[TD="width: 118"]

44​

[/TD]
[TD="width: 118"]

49​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

25​

[/TD]
[TD="width: 118"]

36.1​

[/TD]
[TD="width: 118"]

42​

[/TD]
[TD="width: 118"]

62​

[/TD]
[TD="width: 118"]

70​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

35​

[/TD]
[TD="width: 118"]

36.1​

[/TD]
[TD="width: 118"]

62​

[/TD]
[TD="width: 118"]

70​

[/TD]
[TD="width: 118"]

80​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

50​

[/TD]
[TD="width: 118"]

56.4​

[/TD]
[TD="width: 118"]

68​

[/TD]
[TD="width: 118"]

78​

[/TD]
[TD="width: 118"]

90​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

70​

[/TD]
[TD="width: 118"]

79.0​

[/TD]
[TD="width: 118"]

80​

[/TD]
[TD="width: 118"]

90​

[/TD]
[TD="width: 118"]

131​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

95​

[/TD]
[TD="width: 118"]

107.2​

[/TD]
[TD="width: 118"]

113​

[/TD]
[TD="width: 118"]

128​

[/TD]
[TD="width: 118"]

147​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

120​

[/TD]
[TD="width: 118"]

135.3​

[/TD]
[TD="width: 118"]

(125)
​

[/TD]
[TD="width: 118"]

141​

[/TD]
[TD="width: 118"]

206​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

150​

[/TD]
[TD="width: 118"]

169.2​

[/TD]
[TD="width: 118"]

(138​

[/TD]
[TD="width: 118"]

201​

[/TD]
[TD="width: 118"]

230​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

185​

[/TD]
[TD="width: 118"]

208.6​

[/TD]
[TD="width: 118"]

(191) ​

[/TD]
[TD="width: 118"]

220​

[/TD]
[TD="width: 118"]

255​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

240​

[/TD]
[TD="width: 118"]

270.6​

[/TD]
[TD="width: 118"]

(215) ​

[/TD]
[TD="width: 118"]

(250)​

[/TD]
[TD="width: 118"]

289​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

300​

[/TD]
[TD="width: 118"]

338.3​

[/TD]
[TD="width: 118"]

(235) ​

[/TD]
[TD="width: 118"]

(269)​

[/TD]
[TD="width: 118"]

(319)​

[/TD]
[/TR]
[TR]
[TD="width: 118"]

400​

[/TD]
[TD="width: 118"]

451.0​

[/TD]
[TD="width: 118"]

(265) ​

[/TD]
[TD="width: 118"]

(304)​

[/TD]
[TD="width: 118"]

(452)​

[/TD]
[/TR]
[/TABLE]

 

[tigerpaul]

Thanks chaps, gonna get on the case today.

 

[tigerpaul]

Looks like PVC cables would have been okay but as were using XLPE they are not... Typical!
Hopefully if I get moe info then the adiabatic equation might get me out of a hole..

 

[Engineer54]

Looks like PVC cables would have been okay but as were using XLPE they are not... Typical!
Hopefully if I get moe info then the adiabatic equation might get me out of a hole..

I've got 10mm 2 cores and 4 cores, for SP&N and TP&N DB's
Also 16mm 2 cores and 4 cores, for SP&N and TP%N DB's

What are you talking about?? Look at the table i posted again!!. ....The cables you mentioned above ALL conform with the minimal CSA required for your CPC!!!

 

[Amp David]

Happy days!!:1eye:

Do they still manufacture PVC SWA?