Adding fuses or a CB in a pad mount transformer secondary

Hi All.

I know I’ve seen a picture or two of your typical oil filled pad mounted transformer that had fuses or a breaker installed right off the paddles on the secondary compartment. I tried googling it and could not find any.

I’ve asked our ABB and Cooper reps if they offer and factory installed breakers or fuses and they both said “no”.

Has anyone come across anything like this? I realize on the bigger sizes it may be very difficult to do and be able to get several sets of parallel 500’s landed due to limited room but there would be some instances where it could be an advantage to “move the problem” from the line side of the switchboard main out to the transformer. READ MORE


Need some TCC curves for two fuses – can’t find them

Hi all. I have a pad mounted transformer with internal primary side 15KV rated fuses. There are two types in series. One is an expulsion fuse GE# 9F54WLD303 and one is an oil submersible protector (OSP) GE # 9F59TCD150.

I don’t have them in my SKM library. I asked SKM for them and they sent me new .lib files for these but would not guarantee them. After merging them into my library and adding them to the model I don’t think the curves are correct. I questioned SKM about them and they said they did not have the curves to double check against and that the file they sent me was one someone put together a long time ago and they said they did not know if they were accurate or not.

I’ve searched the web but cannot find the data sheets or curves on these fuses. I did find one reference to one of the fuse types in ETAP but don’t know if maybe ETAP has them in their library.

I have attempted to upload a little info on these fuses from 1986 when we bought this transformer. It is 2 pages, one file. READ MORE