iec 60364-5-52

[Chunkie]

Hi all,

I was wondering if anyone was familiar with IEC 60364-5-52, Table B.52-20, method of installation E32 (using Cable ladder/tray) and de-rating cable as a result of stacking multiple levels of tray vertically.

The standard clearly states that the tray shall be greater than or equal to 300mm from ladder rung to ladder rung, and the table then specifies the de-rate factor for the cables as more and more trays/ladders are stacked vertically. The table illustrates the de-rate factor to apply to a cable based on a 1, 2, 3 and 6 tray stack, again with the 300mm minimum spacing.

the question is, if my vrtical trays are 1m apart can i use a positive detating factor. And how far before the trays are condidered individaully spaced.

thanks

 

[7anoter4]

My edition of IEC 60364-5-52 standard it is from 2001 In this edition Annex B is for information, only.
Also, in the last edition [of 2024?] as I saw, Annex B it is informative only.
So, the actually normative part is still A.
On A 20 it is written:
NOTE 3 Values are given for vertical spacings between trays of 300 mm and at least 20 mm between trays and wall.
For closer spacing the factors should be reduced.
No recommendation for more than 300 mm vertical spacing.
That means these values are the limits.
This table is an extract from VDE 276-1000 which is extracted from
CENELEC Report R064.001 re HD 384,5.523:1991