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Im looking to add a circuit to this sub panel box but when I opened it up I noticed that the neutral (black) connection bar is connected to the ground bar, as circled in red in the photo. Is this normal? Also what is the orange wire? enter image description here

Kokako
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  • It looks like you are in the UK , so I don't know your codes but on the other side of the pond this is common for the main panel to have both the neutral and ground connected even required. About 18 years ago it became a violation to connect the ground and neutral in a sub panel over here but homes that were wired this way prior to the the change are not required to be isolated like current code requires. Hope this helps. – Ed Beal Mar 03 '18 at 00:01
  • Where are you on this planet? – ThreePhaseEel Mar 03 '18 at 01:05
  • This looks like it's actually your main panel -- are there any other panels in the place? – ThreePhaseEel Mar 03 '18 at 02:25
  • There is actually another fuse box in an out building that is first in line. – Kokako Mar 03 '18 at 07:13
  • Is there any chance your power company is giving you two phases? – Harper - Reinstate Monica Mar 03 '18 at 08:05
  • @Kokako -- how many wires are in the cable from the outbuilding to the main building? It looks like it's a 3 wire cable (hot, neutral, something else that might be a hot but certainly isn't a ground) – ThreePhaseEel Mar 03 '18 at 14:50
  • Anyone notice what would be violations if it was US NEC? #1 breakers positioned so down is on. #2 incoming hots going in an almost 2-loop circle around the main breaker, causing eddy currents and inductive heating. (put a clamp meter around the two reds and you'd read double the current in-use). The neutral-ground bond is one of the definitely correct things in US NEC. – Harper - Reinstate Monica Mar 03 '18 at 21:45
  • Harper: down is not on... the first one (hot water heater) is off and so is the 32 (oven) next to it. Power to the house was completely off via the main switch in the outbuilding. You comment about inductive heat generation is interesting to think about! – Kokako Mar 03 '18 at 22:35

2 Answers2

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Orange wire looks like Orion NZ Ripple Signal. Used to manage peak load and related things. Have a look over this link: Orion Ripple Signal Guide

As far as the grounded neutral I suspect this is a main panel (nz “switchboard”) and not a sub-panel

Stanwood
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  • Thanks Stanwood.I think you are correct as that yellow lead goes to the breaker that is used for the hot water heater. – Kokako Mar 03 '18 at 21:15
  • Can anyone explain the rationale for a grounded neural system? Interesting that apparently it's not done any more. This box was put in in 1991... – Kokako Mar 03 '18 at 21:17
  • The green wire heading out of the bottom should be going to Earth. This gives you some protection from an external surge on the black (neutral) wire. E.g., from a lightning strike on the supply pole. Separately, the metal frames on any appliance are tied to ground wires heading back to that panel. If the red wire (hot) shorts to the frame current will flow back to the panel neutral/ground and trigger the circuit breaker. This protects you from a shock hazard. So in one case we bond earth to neutral. In the other we bond metal frames to neutral. In each case we use a green wire. – Stanwood Mar 03 '18 at 21:26
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Time to hit the books. Consider at least reading through

NZECP 51:2004 ISSN 0114-0663
NEW ZEALAND ELECTRICAL CODE OF PRACTICE
FOR HOMEOWNER/OCCUPIER’S
ELECTRICAL WIRING WORK
IN DOMESTIC INSTALLATIONS

http://www.energysafety.govt.nz/documents/legislation-policy/electricity-act-regulations-codes/standards-and-codes-of-practice/

Bryce
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