BS3036 device designation

[PrenticeBoyofDerry]

How do you tell the difference between a BS3036 S1A, S2A and S4A?

 

[Chri5]

T didn't know, but found this:-

you ought to get yourself a micrometer - or at least a good Vernier Gauge for general use, and particularly for this exercise.

However, as this is a company fuse, the heavy odds are that it's 60 Amp (1.53mm dia - assuming it's an authorised fuse element).

80A (1.8mm) and 100A (2mm) sizes are extremely rare in domestic installations.

If you have good eyesight but no micrometer you could compare the fuse element to a sample of 1.5mm cpc ripped from a 2.5mm T&E cable - not very 'scientific', I know, but a useful guide.

Regarding the S1A to S4A rating, this will depend on the type of enclosure around the element on the fuseholder: If the element is entirely open then assume S1A. If it's within a partial surrounding medium of 'asbestos tube' or ceramic guard then you may assume the higher figure(s).

It's a 2008 post from another forum via Lucia.

 

[PrenticeBoyofDerry]

This is the situation:
Old type wylex fuse box, wood and plastic thing (with BS5419 isolator?)
The main fuse is a 1361 80A
The circuits are protected by;
A type 2 BS3871 for the lights
then the remaining circuits are protected by the semi-enclosed rewirables BS3036.
I am trying to figure out what should be the documented rated short-circuit capacity.
The PFC is coming in at 1.54.
The table 7.4 is not that helpful.

 

[Adam_151]

I'm never sure if the wylex standard ones are S1A or S2A (they are certainly not S4A) you could phone wylex technical, or you could rely on the fact that BS5486 part 13 allows it to be conditionally rated to 16ka assuming BS1361 type II service fuse...

Time to recommend replacement anyway, so probably somewhat unimportant anyway!

 

[PrenticeBoyofDerry]

A replacement has been recommended but they don't want to spend the extra money.
But wanted PIR done, not done one for a while, so a bit rusty on the old wylex.
So if it's a type II BS1361 service fuse (which it is), 16Ka is an acceptable entry.

 

[Adam_151]

A replacement has been recommended but they don't want to spend the extra money.
But wanted PIR done, not done one for a while, so a bit rusty on the old wylex.
So if it's a type II BS1361 service fuse (which it is), 16Ka is an acceptable entry.

I'd probably still quote 1ka as the device breaking capacity (as thats what it is), but I'd made a comment in the report about it, allocate it no code and explain that the consumer unit as a whole is conditionally rated to 16ka when installed in a domestic setting and protected by 1361 type II service fuse of max 100A and all devices are correct for the board (remember the 16ka is as a result of tests it passes as an assembly, not individual items)

 

[PrenticeBoyofDerry]

Cheers Adam_151, you have been a great help.