Recent content by RAVWARD

Thanks Everybody. I recall reading this thread, I guess I should have remembered that. Could you advise me, I always come across E type fuse. Why cannot we use K type or T Type fuse. I beleive K type is a fast acting fuse. Could you advise me in what situation I would use a k type fuse. Thanks

Thanks DPC. Here is the SLF http://img141.imageshack.us/my.php?image=fuseuq6.jpg The fuse I selected is 50 amp from Ferraz Shawmut. All of their fuses are current limiting(General Purpose= Current Limiting + Over Load). The transformer damage curve should be on the right hand side of the fuse...

Dpc agreed, That means my so called "Intermediate engineer" is not right. What options do I have. I make it 45 or you could advise me a transformer fusing protection philospohy. I read that it has to do with the transfomer over load chr. also .This bothers me that how to get in to the Over...

Actually, what I am trying to do here is: Selection of a fuse for 1000 KVA, 15.5 KV . The FLA is 37 Amp. Cutler Hammer 40 C was suggested but no reasoning given. I am sure, you guys could advise, what is the criteria for selection of fuse for transformer protection, I beleive overload of...

Hi, How do we decide, if need a HRC fuse for a particular application. I spoke to one of the ferraz shawmut application engineer and he advised me that all of their fuses are HRC. Is there any other type also? Thanks

The fault current depends upon percentage impedance and that depends upon loading. If I am right, then fault current should change. Physical impedance is in ohms. You are right but then why percenatge impedance comes in to play when fault current needs to be calculated. Thanks

Hi, IF case of a 20/26 MVA Oil natural fan cooled transformer, if the base impedance is %z =7 on 20 MVA, and when the loading is 26 MVA, will the percenatage impedance change and so will the fault contribution of Transformer. I mean, will a transformer generate different fault current depending...

I forgot to mention that it is required for mining applications.Mines which are located in arctic locations.

Hi, If any body has come across any guidelines in grounding in rocks and permafrost(A place where soil temp. is below 0 degree cent.). Any ideas to investigate or start an issue like this. Thanks

Thanks. It is a bit confusing though. It says that you can run two cables of differnt voltage levels in case (1)" They are seprated by metal armour or metal sheath or cable assembly listed in Table 19." or(2) seprated by a barrier of sheet steel not less that 1.34 mm thick or flam retardent...

Hi, I am trying to find a code in CSA that states that in a cable tray, No two different voltages level cables can not be laid togather. For example, a 1 KV and a 5 KV cable can not be in the same cable tray. If any body has come across a rule like that. Thanks

Thanks DavidBeach, After reading your post, I called another application engineer and he gave me an answer but it was not that satisfying. I guess, he was close: Here is what he told me, Sheath are normally used in low volatage cables and concentric neutral is used in distribution cables rated...

This is an interesting post but it confused me in my concepts and I called a application engineer in a cable company to clarify what I was misssing here. But he advised me to speak to in Medium Voltage cable specialist. I guess, if some body is here in this forum might be able to put a word to...

Hi Guys, Sorry for pitching in here: To DPC comments: "What continous rating has to do with 3rd harmonic currents". I would appreciate a word, looks like my concept is a little astry. Thanks

Hi This is an interesting post. I did some emerg. gen. installations as a jr. engg. consultant but that confined to 600 V only. But some time, if I come across a transformer connected to a MV generator: I can use the Moral of this story. Please advise me, if I am right. As per Rubulsara...