Medium Voltage Fuses in Fuse Switch RMUs 1

[nightfox1925]

Hello Friends,

We are conducting an evaluation on the existing electrical protection system of a major Oil Company. The downstream feeders consist of 11kV (nominal) RMUs connected as a ring network. We are having difficulty in identifying the make of the fuses being used on these RMUs (Fused Switch Feeders). These Fused Switch feeders are catering power to individual step-down transformers (11/0.415kV). The following are the make of the RMUs in question:
-Yorkshire Switchgear type Tyke II
-Long and Crawford Type GF3F
-Brush Switchgear Type HFU

These are obsolete RMUs. Does anybody have an idea on the typical type and make of the fuses being employed on the fused switch feeders on these RMUs?

 

[ScottyUK]

Brush used to have an in-house fuse manufacturing capacity born out of the Hawker-Siddely fusegear operation.

From the manufacturers involved I will guess that these RMU's are not young. There is a strong possibility that the fuses are to the old BS 2962 standard. Fuselinks to the BS 2962 dimensions and characteristics are made by Cooper Bussmann, among others. The other possibility - less likely in my opinion - is that the fuses are to the DIN pattern. These are readily available from most of the HV fusegear suppliers.

http://www.bussmann.co.uk/New HV/Air section New HV.pdf

There are numerous designs of bolting lug within BS 2962, and some are more common than others. We had a fairly long wait for some 15.5kV fuses to this standard because of the unusual lug type. We bought them through Parmley Graham at Newcastle tel (0191) 478 6222. We have no commercial association with P-G - they just happened to give us a good price and the best delivery we were quoted.

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I don't suffer from insanity. I enjoy it...

 

[nightfox1925]

Thanks ScottyUK. The fuse information will be of help if we fail to get the actual information. Does anybody have a piece for both Long and Crawford and Yorkshire RMUs?

Unfortunately, we are having a very difficult time with our proponent's representative in acquiring these information due to very very nasty bureaucracy they have down here.

 

[nightfox1925]

Hi folks. Here are the fuse details we have based from the nameplate readings we got from site for the two items above:

Yorshire RMU Type Tyke II: Fuse as per ESI 12-8, S.C.
Rating=18.4kA at 12kV

Long and Crawford Type GF3F: Fuse as per BS 2692 and IEC
282, S.C. 350MVA @11kV

Anyone???

 

[andybro]

We use Bussman OHGMA fuses in our Long and Crawford GF3's. I am afraid that I cannot help with the Yorkshire Switchgear units.
Andybr

 

[nightfox1925]

Thank you very much andybro and scottyUK. I actually downloaded the fuse information you have shared via cooper-bussman website. I will try to hunt down for the Yorkshire Units.

Anyone for the Yorkshire Units (two down...one to go).

GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata

 

[ScottyUK]

I must be going daft in my old age. If the RMU fuses are in the oil, the Bussmann link should be:

http://www.bussmann.co.uk/New HV/Oil section New HV.pdf

Page 3 of 10 lists ESI 12-8 fuses: there are five sizes listed.

Apologies for overlooking the obvious - we don't have any oil switchgear at our plant, and it never occurred to me to ask.

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I don't suffer from insanity. I enjoy it...

 

[nightfox1925]

Thanks scottyUK for the link. I am having a strong impression that our proponent is utilizing one type of fuse in all their fused oil switches (GEC, Long and Crawford, Yorkshire, Brush)as per this link:

http://www.defence-estates.mod.uk/p...02/hswn_02-10.pdf#search='reyrolle jkss fuse'

But I will get hold of their guys to confirm that later. I can use this infomation for now in my evaluation of their overall protection system.

Thanks to all of you!!!



GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata