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I have an induction cooktop/stove in a California condo built in 2011-2012.

Recently, I had to pull the cooktop electrical and discovered that the stove has a 3 wire harness (red, black, yellow/green). The building has 4 wires (red, black, white/neutral, and ground).

The builder connected the stove's yellow/green to the building's neutral and left the building's ground unconnected.

Per the manual, I believe they should have connected the stove's yellow/green wire to ground. However, the manual indicates it would be a bare wire and it's actually a yellow/green.

What's the correct way to wire the stove up to code?

wiring

Machavity
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James
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3 Answers3

19

This appears to be a combination of errors:

  • Neutral vs. Ground

The installer is used to typical US 240V/120V stoves which require neutral. So they naturally connected the "not black, not red" wire to neutral. Incorrectly, because that is actually a ground wire and they just didn't know what they were looking at. What they should have done was connected ground wires together and capped the neutral because it is not needed for this stove.

  • Yellow/Green

I'll bet it isn't yellow/black but rather yellow/dark green. Ground can be bare, green or yellow/green.

  • 240V-only

A typical US stove uses 240V for heating elements and 120V for lights and controls. But there is no reason these days to not use 240V for everything (except inertia), as controls are generally running off of a conversion to low voltage DC (so 120V or 240V as the starting point doesn't matter much) and lights are LEDs (again, low voltage DC, not line voltage AC). So a savvy manufacturer may choose, particularly with a new design such as an induction cooktop, to skip any 120V parts altogether. Which conveniently means the same exact cooktop can be used around the world (e.g., 208V - 250V) with no changes needed.

manassehkatz-Moving 2 Codidact
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16

According to the linked manual, you are correct and the installer should not have connected anything to the condo's neutral wire.

The red and black cooktop wires are for the 240V supply and the yellow w/green stripe is the equipment ground.

Correct installation would be:

  • Cooktop Red > Branch Circuit Red
  • Cooktop Black > Branch Circuit Black
  • Cooktop Yellow w/Green Stripe > Branch Circuit Bare

There is no neutral wire on the cooktop so the condo white should be capped off and left in the box.

ThisOneGoesToEleven
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12

In 1966 when they required grounding for everything else, appliance makers got an exception allowing hot-hot-neutral 3-wire connections for ranges and dryers. "What could go wrong?" 4-wire connections were strongly encouraged, then mandated in NEC 1996.

As such, appliance installers generally view the world as 2 types of connections: 3-wire Hot-hot-neutral, or 4-wire hot-hot-neutral-ground.

Becuase the induction cooktop doesn't have an oven, it doesn't need an oven light and has no need for neutral. Therefore it is hot-hot-ground which the installer was unfamiliar with.

Feel free to correct it. Cap off the neutral securely as it can be hot in some conditions. That's why it's insulated.

Harper - Reinstate Monica
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