Transformer Grounding

It is difficult to understand how any organisation can have a <...11KV/0.415KV power transformer to feed various residential loads...>, and not have anyone on the payroll who knows how to write or look after documentation that describes how to install it correctly and how to look after it.

Options:

1. Hire someone
2. Look for employment elsewhere

The codes and standards in effect in the jurisdiction in question will clearly speak to how this system needs to be grounded and how you would go about bonding the neutral to the ground plane you create.

The interesting thing is... I bet those same codes and standards have a section in them about "un-qualified" persons.

Hire someone...

Local electrical codes on required equipment and service grounding apply.

Not sure where you are but in the USA the grounding requirements vary from state to state and also from county to county or city to city in each state.

In my area we are required to install two separate, individual ground rods a minimum of 10 feet apart with the ground connection either exposed above ground or in a ground well with a removable inspection lid.

I suggest you obtain an approved copy of the grounding requirements for the location and react accordingly.

Hear hear!

I have also suggested that before, to no avail.

Sigh...

If one earth were enough, there would be just one connection to save cost.

Consider what happens if the one earth corrodes through ....

The capacitance between the HV windings and LV windings is enough to pass a lethal current from 13.8/12/11/10 KV, to the star point (earth to the user's home) which will be wired to all the exposed metal covering electrics.

The local standards incorporate 125 years experience of how to avoid killing people around electrics. Somewhere in the legal history, there may be cases where someone made it a different way & was judged guilty for a death.

Find out the local standards or ask the electricity distributer.

Read the codes and standards and stop asking us how to do your job. Please. We are not doing you any favours here by helping you and you are not doing yourself (or your customers) any favours by asking an online forum for advice answers on dangerous questions.

No. Neutral should be grounded differently with the body of the transformer. When current is unbalanced in the phases, neutral carries current which must be grounded. Sometimes neutral bears potential also. But transformer body did not carry current or have potential unless there is a fault. Hence it must be grounded separately. Dont use same grounding to neutral and transformer body.