It was common in the ones I saw.
Is this main breaker box and subpanel setup correct?
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You mean because most people are right-handed and it is better for holding a gun and whip while sitting on the left-hand horse.
I think we need to keep track of separate issues here.
TN-C-S only means that a PEN conductor runs from the DNO transformer to the consumer‘s premises. This PEN is earthed at the transformer and often also along the way (PME). At some point the PEN is split into N and earth conductors. This can be done by connecting both kinds of conductors to one connector or by linking two bus bars.
The PEN can also be bonded to an earth electrode at the consumer‘s premises, which is required by many DNOs, but that’s not a necessary condition for a TN-C-S system.
The questions OP needs to ask a local electrician are
1) Is this a TT or TN supply?
2) If TT, is there a proper earth electrode?
3) If TN, where is the PEN to be split and does it need to be earthed?
TN-C-S only means that a PEN conductor runs from the DNO transformer to the consumer‘s premises. This PEN is earthed at the transformer and often also along the way (PME). At some point the PEN is split into N and earth conductors. This can be done by connecting both kinds of conductors to one connector or by linking two bus bars.
The PEN can also be bonded to an earth electrode at the consumer‘s premises, which is required by many DNOs, but that’s not a necessary condition for a TN-C-S system.
The questions OP needs to ask a local electrician are
1) Is this a TT or TN supply?
2) If TT, is there a proper earth electrode?
3) If TN, where is the PEN to be split and does it need to be earthed?
The Protective Multiple Earthing (PME) system is termed
MultiGrounded Neutral (MGN) in North America
and
Multiple Earthed Neutral (MEN) in Australia New Zealand.
THE Protective Earth (PE) conductor is connected to the Neutral
to provide a Low Impedance path
in order to operate a "Protective Device", (Fuse or Circuit Breaker)
in the event of a Line to PE fault condition,
to disconnect the "Supply".
This bonded "Earth Electrode" plays no part in disconnecting a circuit - by the operation of a Fuse or Circuit Breaker -
in the event of a "Short Circuit" between the Line
and
any metal "casing" connected to the Protective Earth (PE) Conductor which is connected to the NEUTRAL.
(This is part of "Equipment Grounding".)
Although (in a PME/MGN/MEN system) the Earthing/Grounding Electrode plays a role in reducing the overall impedance between the Neutral and the "Earth",
its primary purpose is to provide a "Low IMPEDANCE" path for the "discharge" of "transient over-voltages".
(NEC) Regulations in North America recognize that it is unlikely that any single Earthing/Grounding Electrode will provide a low Resistance path to Earth.
Hence, unless it can be proved that any single "Grounding Electrode" has less than 25 Ohms resistance,
(a minimum of) TWO Grounding Electrodes are required at any installation (at least 1.8 m [6 Feet] apart.)
These Grounding Electrodes are required to be connected together
and to the "system"
by wiring which is "no longer than necessary and without any unnecessary bends".
As I have posted previously, these and other matters are discussed (at length) in
"System Grounding" is discussed from 21:10 to 28:30.
"Equipment Grounding" is discussed from 28:30 to 34:50.
(The "Myths" section from 34:50 may also be of interest.)
After viewing the section on "System Grounding" above, you should realize that
the Electrician who connected this Earthing Electrode did not understand the purpose of what he was doing.
