W, TL & T rated fuses [American?] cf. Canadian 'P' & 'D' rated fuses

[crshears]

Hello again all,

For the background to this post, please refer to:

http://www.eng-tips.com/viewthread.cfm?qid=356842

- Legacy Shipboard DC System Now Operating on AC.

I'm wrapping up the task of properly co-ordinating the 'hot' versus neutral fuses in all the old distribution panels.

Problem: since the old girl has spent time in both Canadian and US waters, there are quite a few different classes of plug fuse in use. For instance, there are many of the types W, TL, T and TC; as near as I can tell these are US designations. In addition to these, there are some that bear only the general and less-than-completely-helpful information 'time delay fuse ## amp...'

There are also numerous P and D fuses in use; Cooper/Bussmann describes these as 'rating for Canadian applications.'

To further complicate matters, virtually all of these come in 15, 20, 25 and 30 amp varieties.

What I'm looking to find out is where in the W / TL / T [/ TC?] continuum to sandwich 'P' and 'D' fuses...are the 'P' and 'D' ratings equivalent to specific US ratings, or do they fall somewhere in between, and if so, where? I've been doing Internet searches on the foregoing using evey term I can think of, but I'm still coming up short, no pun intended. Maybe it's that I don't exactly know what I'm looking at, but I've also tried to compare the various inverse current/time characteristics plotted out on the spec sheets provided by various manufacturers, but enlightenment has not come to pass.

H-E-L-P!

Carl

 

[crshears]

It might be of use to know why I'm asking...

I have placed fast-acting 15 ampere fuses in the hot side of all branch circuits aboard in order to provide as much conductor protection as possible; there isn't a lot of it, but the oldest wiring is cambric-covered, and to minimize the fire hazard I want to expedite the clearing of faults.

These fuses won't tolerate much in the way of motors, hovever, and I do know that the cleaning staff will be using powered floor vacuum cleaners on the carpets, and the tradesmen will be using table saws, grinders, and such...thus I will have to expand the protection envelope enough to safely accommodate these circumstances.

That being understood, I do not want to expand the circuit protection any more than absolutely necessary, hence the desire to know with a fair degree of precision the characteristics of the fuses under consideration.

Thanks for listening.

CR