HRC Fuse Assemblies – A Cloud of Confusion?
With the update of the NSW Service and Installation Rules in July 2018, many electrical contractors and suppliers are uncertain as to what to look for in Service Protection and Meter Protection Device products between brands to ensure compliance with the latest rules.
For single domestic installations there are two options:
- Installing an SPD rated a maximum of 100A and an MPD rated at a maximum of 80A, or
- Installing an SPD and MPD as one device, however it must be rated at the lower current carrying capacity of 80A being the maximum rating for an MPD HRC fuse, of course the amperage rating may be reduced for installations with a lower maximum demand.
When opting for option 2, does that mean that the HRC Fuse carrier is now labelled with a rating of 80A equal to the rating of the fusible link installed? – NO. The Fuse assembly must still be rated and labelled 100A in order to comply with the rules. This may seem confusing, as it has long been the normal and compliant process to label an electrical product with the appropriate maximum rating which in this case would be 80A the maximum rating of the fusible link installed.
So, if it is a requirement to label the HRC fuse carrier 100A then considering the variety of current capacity ratings of fusible links that come installed in HRC type fuse assemblies, how does the installer know the rating of the fusible link installed in the fuse carrier? Simply by the manufacturers identifying product code. The rules do not preclude labeling the product with the manufacturers product code.
It must be noted that the Service and Installation Rules state that the rating of the fusible link installed in the fuse carrier of the fuse assembly must be labelled beneath the device within the electrical enclosure it is installed in.
CSG range of HRC type Fuse Assemblies are fully compliant.
Check out our range of HRC Fuse Holders and Main Fuses today!