Tripped Substation

[chadwiseman]

Hi, I'm trying to put together a safe work procedure for a tripped mobile substation (delta-wye) that is resistance grounded. When we have a ground fault, is there a safe way to approach the substation? While most codes say we should limit our GPR to 5000V, we have the possibility of reaching 15000V, which can make step potential high. Any advice, or research material would be apprecaited.

Thanks.

 

[RalphChristie]

I am not sure if I understand your question correctly.

Ground-fault primary side or secondary side?
On the secondary, that is one of the reasons for resistance grounding, to limit your GPR to a save value. What is your voltage level and your resistance value?

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[chadwiseman]

A fault on either side (primary or secondary) would be a concern. The voltage is 46/4160 and is grounded through 96 ohm resistor.

 

[Alex68]

I suppose that you cannot improve the grounding grid of your MOBILE substation.
You could increase the additional resistances like imposing the use of isolating shoes and glovers

 

[PowerfulStuff]

86ranger,
Even with boots and gloves, there's always the potential to trip and get electrocuted. Are you able to supply an above ground earth grid (e.g. cyclone wire tied together with copper bonding conductors) to make it safe? Should the area be fenced off to ensure no-one is walking past when there is a ground fault?

Regards,
Martin