Electrical – Should the neutral and earth bars be connected in this situation

electrical-panel

This is in Guatemala, in a semi-rural area, so there are no codes as such to be followed. Also local electricians are mainly DIYers like me, so I haven't gotten much consistent help there.

I have the power connected to a meter on a post by the property edge, this was done by the power company and has the earth (copper bar) and neutral connected inside a small box in the post. There is a 50 amp breaker on the hot wire. From this post, there is a 22 meter run of #6 cable to the house, neutral and hot wires only. This is going underground, and can't be changed easily. At the house there is a panel with slots for four breakers only, which will do as it's a small weekend house.

I plan to connect a copper bar earth at the house, my question is should the earth bar be connected to the neutral bar? The panel has an aluminium jumper to connect the two, if I should. I have read that in the US sub panels must not have the earth & neutral connected, I'm not sure if this counts as a sub panel or not.

It's a single 120v supply, i.e. two wires only, but I want to put earthed sockets in the house. The earth from the house panel will be 20 meters away from the earth at the power supply post, if that makes a difference.

Thank you for your attention.

Best Answer

Better idea -- move that 50A breaker to the box, and put a non-fused safety switch at the pole

What you can do instead of having the redundant neutral/ground bonds at the pole and the house is:

  • Have the utility cut the power
  • Move the 50A breaker to the box on the house as it'll be the house main breaker. Remove the box from the pole.
  • Put a 2 pole, non-fused, outdoor type (NEMA 3R enclosure) safety switch (UL98 listed, with a minimum fault current rating of 10,000A and a minimum working current rating of 50A) in place of the box on the pole that had the 50A breaker there. Siemens, GE, Square-D, and Eaton all make quite suitable units, although they won't exactly be cheap.
  • Land the hots on one pole of the safety switch, and the neutrals on the neutral/grounding block in the safety switch. Torque all connections to spec, and make sure that any grounding electrode wires at the pole that went into the old box go into the neutral/grounding block on the safety switch. You will need to make sure this block is bonded to the enclosure as well.
  • Put a "METER DISCONNECT -- NOT SERVICE EQUIPMENT" label on the safety switch (inside cover is good, but don't put it over the existing labeling there).
  • Have the utility turn the power back on

This is a hot sequence meter disconnect as per NEC 230.82(3), and provides the best of both worlds:

  • You can cut off power to your house completely at the pole, allowing you to work on the box on the house safely
  • The neutral-ground bond, though, can still live at the house, allowing that to be the main panel, and allowing you to safely use the existing ungrounded feed from the pole.
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