NEC 110.26 Working Clearance 2

[VTer]

Hi All,

Is anyone aware of equivalent IEC or other international code/standard that may include the equivalent requirements for working clearances similar to those found in NEC 110.26?

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic ù and this we know it is, for certain ù then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". û Nikola Tesla

 

[FacEngrPE]

These threads discussed the above question.

https://www.eng-tips.com/viewthread.cfm?qid=287852

and

https://www.eng-tips.com/viewthread.cfm?qid=193769

 

[VTer]

Thanks for the response FacEngrPE but it appears that neither thread really addresses my questions about the working clearances of electrical equipment below say 1000V or 600V.

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic ù and this we know it is, for certain ù then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". û Nikola Tesla

 

[FacEngrPE]

It has been a while since I needed to work with those standards. Here are some things to try BS:162. extends down to 415V

https://electricalnotes.wordpress.com/2011/04/22/minimum-electrical-clearance-2/,

but you probably are looking for clearance in front of a panel board.

This document from Siemens

https://new.siemens.com/global/en/markets/panel-building/eu-directives.html

indicates that the information you are looking for might be in IEC 60204-1, “Electrical equipment of machinery" or IEC 61439. I do not have access to these standards so there is some guessing here.

IEC design is a way to create safe electrical system, but is very different from NEC / NEMA design.

 

[che12345]

Dear Mr VTer (Electrical)(OP)4 Mar 21 16:31
V. "...Is anyone aware of equivalent IEC or other international code/standard that may include the equivalent requirements for working clearances similar to those found in NEC 110.26?..."
C1. There are German Standard per VDE 0100-Part 729 applicable for < = 1kV as follows:
cubicles with > = IP2X : (Refer IEC definition for IP )
1) between cubicle front to wall; 700mm,
1.1) between protrusion switching handle to wall ; 600mm,
2) between cubicles, cubicle front to front; 700mm,
2.1) between switching handle protrusion between front to front cubicle; 600mm.
C2. Please refer to VDE 0100-Part 729 for full detail.
Che Kuan Yau (Singapore)

 

[FacEngrPE]

I followed up Mr che12345's reference, and found reference to

IEC 60364-7-729 Low-voltage electrical installations - Part 7-729: Requirements for special installations or locations - Operating or maintenance gangways (IEC 60364-7-729:2007, modified); German implementation HD 60364-7-729:2009​

in a paper from a German panel board manufacturer Hensel (attached), and then found this discussion
Planning and installation of the low voltage switchgear – The devil is in the detail!
Fred

 

[che12345]

Dear Mr FacEngrPE (Mechanical)6 Mar 21 17:31
F. "....I followed .., and found reference to ...IEC 60364-7-729 Low-voltage electrical installations - Part 7-729: Requirements for special installations or locations - Operating or maintenance gangways (IEC 60364-7-729:2007, modified); German implementation HD 60364-7-729:2009..."
C1. Thank you very much for the learned advice, pointing out the IEC reference.
C2. I notice in the Hensel document in page 5 " switchgear assemblies must be set up so that the minimum aisle widths are not exceeded. ".
I think it could be a translation error? It "should be?" " switchgear assemblies must be set up so that the minimum aisle widths are not reduced. ". ?. Please advise. Note: English is not my mother tongue.
Che Kuan Yau (Singapore)

 

[FacEngrPE]

English is likely not the first language of the Germans that wrote the Hensel document.
On page 5 I find both of these statements adjacent to the illustration:

Installation site Switchgear assemblies must be set up so that the minimum aisle widths are not exceeded.
Aisle width The aisle width in front of switchgear assemblies with drives, e.g. switches, must be at least 600 mm.​

I agree with your opinion the first statement is an incorrect statement, I suspect the German in the original document has an awkward direct translation to English. I think the important point being made is that the handles and other protruding items can not obstruct the minimum isle width.

The other document I cited (the link) has some similar illustrations, and also agrees with your interpretation of the isle way. The second document also makes a point that the OEM may indicate that a minimum clearance is required to service the equipment, and the OEM minimum clearance can be wider then the isle way requirement.

Fred

 

[che12345]

FacEngrPE (Mechanical)7 Mar 21 03:03
F. " English is likely not the first language of the Germans that wrote the Hensel document.
On page 5 I find both of these statements .....Installation site Switchgear assemblies must be set up so that the minimum aisle widths are not exceeded*. ... Aisle width The aisle width in front of switchgear ...."
I agree with your opinion the first statement* is an incorrect statement, I suspect the German in the original document has an awkward direct translation to English. I think the important point being made is that the handles ..."..
C. Thank you very much for your learned clarification/advice. Case closed.
Che Kuan Yau (Singapore)