The house I'm renting has a very old (fire-prone) Zinsco panel. There are only 7 breakers for the entire house, and shared neutral multi-wire branch circuits all over the place.

At the moment, breaker/circuit 3 is only controlling the garbage disposal.

Breaker/circuit 4 is a GFCI that controls two receptacles (air fryer / water dispenser / electric toaster ), the dishwasher... oh, and the fridge!

NEC says shared neutrals should be on double pole circuit breakers. These are not. They're also relying on the metal box / screws as the neutral, which I don't love, but alas...

I'd love to separate some of those out, but here's my setup:

weird wiring

My hope was to not fish new wire or break into drywall by:

  1. Getting rid of the button (since it controls both plugs below the sink).

  2. Running the dishwasher into the receptacle under the sink

  3. Installing an air switch for the disposal.

  4. I was possibly also thinking of wiring this GFCI into circuit three (to have disposal, dishwasher, and air fryer on one circuit — keeping some stuff away from the fridge circuit).

But this setup is with the shared neutral is confounding...

I'm guessing it's something similar to this video here, but the half-voltages issue is weird. Especially since there were three neutrals connected to the GFCI plug.

I'm somehow getting measuring 60V on the wires of the switch, but it turns into 120V down below when switched.

Must be another junction box somewhere else, right? What am I missing here?

  • 1
    I'd think twice before doing any electrical work in a place I was renting. Many leases strictly forbid it as do many local ordinances. Your experience level in this area is lacking a bit and you could be putting future renters in harm's way.
    – JACK
    Commented Sep 28, 2021 at 19:22
  • Absolutely agreed. Unfortunately, my landlord refuses to get the panel switched out (or to pay for an electricial to come out — despite the fact that I've already found code violations all over the place). Since I just moved in, I'm not looking to escalate quite yet. Just trying to get this as safe as I can by myself while keeping track of everything I do. If it's easy (and safe) enough, I'll do it myself. If not, I'll pay out of pocket for an electrician.
    – Joe
    Commented Sep 28, 2021 at 19:31
  • 2
    If the rental unit is insured, find out by whom and let them know there is a zinsco panel there. Maybe they could say they are doing a routine inspection of covered properties so it doesn't look like you ratted him out. You can't even sell a house these days with a zinsco panel. Commented Sep 28, 2021 at 20:51
  • You are probably getting phantom voltages caused by induction of wires running some length close to each other. You could rig up a load, like an incandescent light bulb (NOT LED or CFL) across the circuit and see if the voltage drops to almost nothing....it should. Digital multimeters are very sensitive and put zero load on the circuit. I've worked on circuits that were turned off, but showed 170 volts. There was enough induced current to actually shock me, had to wear rubber gloves to complete my work. Commented Sep 28, 2021 at 20:57

2 Answers 2


It's really time to get an electrician there. There are so many things wrong, it would be irresponsible to try to help you. The reason you're getting 60v is you're measuring across a switch circuit and your meter is partially completing your circuit to the garbage disposal.

Also, a 1-1/4 HP disposal really should be on it's own 20a circuit. I would also recommend it be hardwired and controlled by a 20 amp commercial grade switch.

  • DrSparks, agreed. both the garbage disposal and DW should be on individual circuits. I also like to put the fridge on an individual circuit...you don't want it to loose power due to a tripped GFCI or AFCI and have your food ruined. I do disagree that it should be hardwired, I have one controlled by an air switch and it's worked great for 15 years. BTW, love your pic: ONE MILLLLION DOLLLLARS, OH BEHAVE! Sharks with laaaassser beams. Commented Sep 28, 2021 at 21:11
  • Lol thanks. Frickin laser beams. Yeah I'm hearing good things about those air switches. I think buying a quality one and not a cheapo is key. They all have a HP rating on them. I've put a few in and had good results. The great thing about them is they are guarded and help prevent inadvertently turning the disposal on. Also, completely electrically isolated so no wet hands touching a 120v switch.
    – DrSparks
    Commented Sep 28, 2021 at 21:14
  • 1
    The air switch I use actually has two outlets on it, one is for the garbage disposal, the other is for an instant hot water dispenser, both on one circuit. It cuts power to the instant hot when the disposer is being used, saving having to run 2 circuits. Frankly 2 20 amp circuits isn't enough for a kitchen these days. I run 1 for the DW, another for the instant hot/garbage disposal, one for the fridge (isolated) and 2 for convenience outlets. And that doesn't even count an electric range. In other news: ...Frau Farbissina: RELEASE THE FEMBOTS Commented Sep 28, 2021 at 21:54
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    Throw me a frickin' bone here!
    – JACK
    Commented Sep 28, 2021 at 22:07
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    All the musing about dedicated circuits in the kitchen is great. Remember, though, that the OP has a Zinsco Fire-Starter™ panel with 7 wait, really? only 7 breakers for the entire house.
    – FreeMan
    Commented Sep 29, 2021 at 12:49

You need 2 things to work on a rental unit

(whether you are landlord or tenant):

  • The landlord's consent to the work.
  • A licensed electrician, OR, the AHJ's consent to do the work without an electrician typically granted when the work is trivial.

The AHJ is the local body which issues permits and does inspections.

... um, don't quit your day job

Because you possess something that is described by Neil DeGrasse Tyson better than I possibly can.

No offense.

You are trying to "correct" Code violations that aren't actually Code violations, and you are committing Code violations in this quest. The lack of handle-ties are legal because they are grandfathered. There is no Code requirement to replace Zinsco panels. Do you have the torque screwdriver to comply with 110.14(D)?

See, you are nitpicking about code violations you're heard about, while committing ones of your own.

That's just not going to work. Bring in a pro to button this up, and then, ask permission of the landlord for any future projects, and work with the AHJ to determine to what extent you need an electrician.

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