Multiple Fuses protecting one circuit

[roukel01]

Hello All

I came accross a 3 phase sub main the other day which was protected as follows:

50mm SWA Cable. From the main distribution board, a 200A MCCB. From there into a switch fuse isolator 200Amp general rated fuses.
From there clipped direct through a large storage shed into another iswitch fuse isolator , this time labled up to use 160Amp fuses. It then went into a busbar chamber, connected to a 3 phase kWh meter and then into another switch fuse isolator labeled to use 125amp fuses.

The sub main feeds nothing else along its run and is then terminated into a contol panel.
Although a little strange set up, is it ok? does it break any reg rules?

Cheers all

 

[ian.settle1]

Hello All

I came accross a 3 phase sub main the other day which was protected as follows:

50mm SWA Cable. From the main distribution board, a 200A MCCB. From there into a switch fuse isolator 200Amp general rated fuses.
From there clipped direct through a large storage shed into another iswitch fuse isolator , this time labled up to use 160Amp fuses. It then went into a busbar chamber, connected to a 3 phase kWh meter and then into another switch fuse isolator labeled to use 125amp fuses.

The sub main feeds nothing else along its run and is then terminated into a contol panel.
Although a little strange set up, is it ok? does it break any reg rules?

Cheers all

Easier to isolate and lock off a 200A switch fuse than a MCCB.

Was it that the busbar chamber location a seperate company at one time who was leasing a portion off the site from the main site owner so the 200A switch fuse was the main site owners point of isolation and the 160A switch fuse the person leasing the building point off isolation

 

[roukel01]

Basically one company is buying their electricity from another because they do not have their own supply. It just seemed a little strange having 4 lots of protection for one circuit.

 

[swparksey]

Basically one company is buying their electricity from another because they do not have their own supply. It just seemed a little strange having 4 lots of protection for one circuit.

In my book you can never have too much protection, (If had has heeded this advice I wouldn't have spent the last 16years paying child support)

Does seem a bit OTT, bet it was put in phases by different people, we see this allot, nothing really wrong though in my book.