.svg)
The NICEIC takes us through the regulatory requirements for selecting the right protective equipment.
This Q & A is one of the thousands posted in our Technical Expertise area and answered by our Voltimum Experts.
Question:
Can a switch fuse be the same size as the main incoming one, or would the switch fuse need to be lower rated than the main incoming fuse?
Example:
Main incoming fuse 100 amp
Switch fuse 100 amp
25mm tails
Answer:
NICEIC Technical Expert
Regulation 536.3 requires the co-ordination of equipment by selecting OCPD’s in series so that they provide safety and continuity of service.
The selectivity of OCPD’s for overload are covered in regulation 56.4.1.2 and for short circuit protection, regulation 536.4.1.3.
To meet this requirement we would recommend a lower rating OCPD in the switch fuse.