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Hi folks, With respect to switchgear tripping supplies, we can supply these externally via, for example battery backed source. Do these panels typically have an internal DC distribution bus to distribute the power to each section or do you require to run a cable to each section individually...

Haha nice. Yeah I can definitely see the advantages. Thanks for your advice

Thanks Dave, sounds like an interesting project. That's great, I'm not so familiar with the internal time delay of the relay itself, I guess you can get it from the specs. What do you think of these ZSI schemes? Do you think they will become more common place?

Hi all, Does anyone have experience with implementing ZSI protection schemes on MV distribution networks. My understanding is that a 200ms time margin is usually used between levels however I am not sure where this comes from. Any thoughts? AVR

Much appreciated, thanks for your help.

Thanks RRaghunath, This is what my understanding was too; there is no benefit from this coordination as I can see?. 1) Under this circumstance am I correct in saying that the HV breaker must also protect for a 3 phase short circuit at the LV transformer terminals before the LV incommer...

Is it standard practice to place inter-trips on the MV and LV breakers when grading across say 1 2MVA tx feeder? - Assuming a single transformer single bus arrangement (no bus couples or parallel tx feeds). In such a case, my understanding is that the MV breaker should grade with the largest...

Nothing wrong at all with the conventional switchgear. I was just wondering if anyone had installed it / had any operational experience with it.

Thanks dpc, I was thinking 11-33kV. We have a lot of sf6 here in UK, for ring mains and main distribution boards. There is a trend towards non sf6 types due to the environmental issues associated with sf6. I am fairly familiar with VCB's which are used a fair amount here too, but I was...

Hi folks, Anyone have experience with non-SF6 MV switchgear alternatives (like ABB dry air)? What is it like, any pros or cons? AVR

7anoter4, Amazing thanks for this, this is what I was looking for. I know at LV, in domestic scenarios there are challenges around terminal ratings, when 90C cable is used. Was looking for the reference at HV, much appreciated. AVR

Hi folks, Can anyone point me in the direction of the temperature rating for 11/20/33kV cable terminations? Is this 90 degrees as per the cable conductor? AVR

I've seen something recently about switchgear with a so called maintenance switch, whereby a faster trip time is set before you enter the vicinity of the switchboard, hence reducing energies. Eaton Arcflash Reduction Maintenance Switch and Schneider (https://www.se.com/us/en/faqs/FA272576/) are...

Hello there, I was wondering if anyone could help me with my understanding. If I have a building protected by a lightning protection system with its own electrode, this LPS needs to be bonded back to the Main Earth Bar of the (power) electrical system at a single point. If this power...