Decrease font size
Increase font size
Topic Title: BS 7671, IEC - Breaker and Cable Sizing
Topic Summary: IEC MCCB
Created On: 16 May 2018 11:58 AM
Status: Read Only
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 16 May 2018 11:58 AM
User is offline View Users Profile Print this message


Posts: 20
Joined: 21 April 2018

How to size the conductor & breaker for group of motors/mixed loads using IEC standards. (for example in NEC, the article 430.24 & 430.62 is used); I did a google search and all I could find is to use a type -2 co-ordination chart for single motors and I could not find anything for breaker sizing of feeders
 16 May 2018 12:50 PM
User is offline View Users Profile Print this message


Posts: 17623
Joined: 13 August 2003

BS 7671 doesn't specify any particular method for sizing distribution circuits - rather it's up to the designer to consider the design load (possibly thermal equivalent current), starting currents and duty cycles, diversity on so on - all according to the particular conditions of the installation. I'm sure some here could give you some rules of thumb, and some guidance documents provide some (often conservative) diversity values for some common domestic and commercial situations, but ultimately it's down to the designer's understanding of the installation, the load equipment and now it's likely to be used.
- Andy.

New here?

See Also:

FuseTalk Standard Edition v3.2 - © 1999-2019 FuseTalk Inc. All rights reserved.