MV RMU using Time lag Fuse conforming to ESI 12.6 standard

[matwong]

Dear all,
Any idea how well is the MV RMU (especially 11kV) using LV TLF performing in the industrial/utility company worldwide ? Our company has recently attempted to use this type of RMUs but somehow we have difficulties in sourcing for the fuse-link. It appears that only GE can produce this type of fuse-link and there is not much saving in term of fuse-link cost as compared to MV fuse-link. Are this type of RMUs getting phase-out? Your comment & experience is highly appreciated.

 

[emeryn]

The company I work for manufactures in excess of 500 ring main units a month that use TLF fuses in the protection system, so they are not being phased out. Although we do have options that use a relay.

The fuses that are generally used are an XF type (not sure of the make)but they are readily available and I would expect them to be significantly cheaper than a MV fuse.