PC Electrics

I have a copy of pages 136 & 137 of the 13th edition regs (defo from 1966, so I think it's 13th or 14th ed). These pages have the tabulated ratings for imperial cables (table 3).

Above the table in bold print it says:
"The ratings tabulated apply where the cable is provided with coarse excess-current protection. For close excess-current protection see rating factor below"

In the rating factors below the table it says:
"The ratings tabulated may be multiplied by 1.33 where close excess-current protection can be assured (see item 2(b) on page 127)"

Does anyone out in Leccyforumland have a copy of 13th edition and can either reproduce the text of item 2(b) from page 127 in this thread or post a scan on a photo host site?

I want to know what is meant by close and course excess-current protection. My current interpretation is that course is 3036 rewirable and close is 1361 fuses or MCBs. This would certainly make sense as the 1.33 multiplication factor applied to table 3 would be the same as the 0.75 factor applied to 16th ed'n ratings for 3036 rewirables.

My ultimate goal here is to understand imperial cable ratings better as I come across a fair bit of it during CU changes.

Thanks

PCE

ian.settle1

If I can remember from when I was at college when the 14th was going they where classed as the following:

Coarse was rewireble fuses

Close was cartridge fuses

PC Electrics

Thanks Ian, that pretty much confirms what I thought. 14th was before my time and I was a little confused that the ratings seemed lower than the metric equivalents, but really it's just the way the figures and rating factors are presented compared to 16th.

rumrunner

Hi,
All the cable ratings etc in the 13 edition are metric. and to confirm ians answer course excess current protection is rewireable fuse,close was for rcd or cartridge fuse ,as far as i can remember.
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