Kitchen Sub Panel Pt.2 - wiring circuits

Starting to pull some wires and wire up the sub panel circuits. 

It's good to keep it tidy because there are going to be a lot of wires in there.  

Did some rearranging... not written down is I decided to throw the laundry outlet on this sub panel. "C outs is the required 2 countertop circuits" fit into a single space (they sell two 20A (and other amperages) breakers that fit into one typical space). "Disp" is for the under sink outlet used for the in sink disposal. 

If you have a dishwasher and a sink disposal, you put two circuits on one outlet! I told you there are a lot of circuits! You get to break these little tabs on the outlet that connect them together. It's a very special experience which is most commonly done for this exact application. Also done for switched outlets used for lamps but that's pretty rare these days. This house has quite a few of them.

If I had room for a dishwasher, I would be averaging one outlet per circuit - I have one counter circuit that has two outlets. Seems crazy but I think the reason for that is the modern American Dream is to have your kitchen remodeled every 10-20 years so the sub panel makes this easy.

This panel is wired

Tested and labeled circuits

Sub panel is done! I double checked each circuit with a beeper before labeling. The black plastic hole cover is only needed if you accidentally break out more grey metal tabs than you need to. 

Kitchen Sub Panel Pt.1

The modern kitchen usually needs an electrical sub-panel because nearly everything in the kitchen needs its own circuit. Basically the best rule of thumb is if there's power going to something, it needs a circuit.

How many circuits could this small, galley kitchen really need? I'm keeping the cabinets and layout for now because a kitchen remodel for the house will involve pushing out a wall that will probably need to be cantilevered etc. etc.... expensive.

I started marking out the circuits of this basic kitchen: 

The C outs 1&2 is for counter outlets. You need two circuits. I have two outlets on one side and one on the other. That's 2 20A circuits for 3 outlets. It's much more than adequate but that's code. 

This is a silly amount of circuits. A regular 20 amp outlet circuit is good for like 20 outlets that could have high draw things like electric space heaters. Why would you need a circuit for an outlet for the gas range? Most gas ranges only use the outlet for the clock or light (old school) or igniter which are WAY below the 20 amps afforded by the wiring and breaker.

One reason is cosmetic - the click of the igniter could make overhead lights flicker. Besides that, I'm not sure since you don't need to turn off the circuit to unplug a gas range, which would be another reason to have a breaker for something, so you could shut off power to change out the appliance. Just in case you need to move the outlet every time you change ranges? I don't know...

Anyway, I started making note of all the circuits and getting ready to put in the sub panel. 

Above you can see an 8 slot, 125A sub panel that will be sufficient for the current kitchen and future kitchen. The conduit formerly called BX now MC, is to protect the cable when it is exposed like under the house where it will be running. I used 3/4" for 4/3 copper because that's all they had but I recommend 1" conduit (also called FLEX). 

27' of 4/3 copper and 25' metal conduit is about $130! 

The max current draw (amperage) is determined by the application. Common amperage ratings are 15A for lighting, 20A for outlets, and 30-50A for an electric oven.  The largest draw of electricity is turning electricity directly into heat - like a space heater, hair dryer and electric oven.

Amperage also determines the wire size. 15A is 14 gauge, 20A is 12ga., 30A is 10ga. etc. When the wire has a lot of current going through it, it can get hot and spark and cause a fire. That's what the breaker is there to prevent - to much amps. You can have an undersized breaker or fuse for the wire, but not an undersized wire for the fuse because that would be dangerous. 

Here's a chart at Home Depot: 

WOW COOL! NOT CONFUSING AT ALL! 

If the sub panel is 120A, then we need #4 copper NM wire. But that's only rated for 70A you say. Ahh very observant, grasshopper! 4/3 is #4 wire, 3 conductor, with ground. You actually have 2 hot wires, each rated at 70A - so 140A for a 120A panel - we are good. The two hots are so that  each side of the panel has its own wire.

But the four slots on one side can hold more than 70A! you say. That's OK because we have a breaker upstream. This is a sub panel and has a main breaker going to it in the main panel. Since the main panel is going to be a huge expensive pain with PG&E, I will tie into the former range oven "safety switch," which is a dual 60A switch. 

Here is the electric range shutoff, which may be original but may be added in the 50s - not sure. Regardless the kitchen originally had an electric range, which was VERY unusual for '27, and also a common Maybeck feature. 

Here is our dual 60A safety switch formerly used for the electric range. I am using it temporarily as the kitchen sub panel shutoff, until I can afford a new main panel and service. 

Above: each hot (black and red) has a 60A fuse, allowing 120A of 110v, perfect for 4/3, each #4 rated at 70A max, plus a #4 neutral, white, and a smaller ground.

I don't recommend pulling 4/3 through a 3/4" flex conduit. Use 1" or bigger, or 4/3 MC cable (already wrapped), and save yourself a struggle. This is the line from the sub panel. 

On the left top and bottom are some 3/4" BX conduit. The bottom is the feed to the former electric range. The top is the power coming in, that comes from the main junction box, behind the main shutoff switch.

Cleared out the old stuff, pulling that 4/3 into the box  

The sub panel is hooked to a main switch now so when this switch is down, I can work on the sub. I had to turn off the main power to the house to work in this box. Fortunately, now I can simply switch off the sub panel and only the sub panel here now. The neutral and ground are "bonded."

Now I have the kitchen sub panel on a shutoff and I can safely work on wiring up these kitchen circuits. To be continued... 

Another broken 3-way Switch :/

As I've become familiar with the house wiring, I've been annoyed by the weird crap done to a house that was originally modestly, but cleanly wired. Most annoying is the fact that the house had 4 3-way switches that no longer work in very useful places. As you may know, a three way switch is a pair of light switches that can both turn on or off a light. This is VERY useful for a room that has multiple entrances. If a bedroom has a bathroom or back door connected to it, as well as an entry from a hall, you want to be able to turn on the list when entering from either door, and turn off the light when leaving through either door. Makes sense right? When people who have no business fiddling with home wiring mess with a three way, this is usually what happens:

Wouldn't it be great if the stair lights turned on and off at the switches at either end of the stairs, like they used to? 

To explain what is effectively happening: 

Another hint it's an incorrectly wired 3-way, besides the written clue and the two switches, is there is no "OFF" written on this part of the switch, because whether the light is on or off depends on the position of the other switch

If you have this problem in your house, either read my posts about three ways or leave it alone! Thank you

-Public Service Announcement from Residential Electricians

To fix means this again:

Yep it's a three way. Using your beeper lets you determine what's the hot wire and what's going to the lights. 

Lights go to the black/common pole

In these setups, the switch next to the light has the wire going to the lights that connects to the black screw while the other box has power going in and that goes to the black screw over there. The two other wires go between the boxes and the power goes through to the light when both switches are switched to the same wire. 

OK that's working. Now another one :/ 

Same situation as before in the music room also

Kitchen/Laundry Flooring

Unfortunately, I can't paint the subfloor under the linoleum, as I had planned, for two reasons. First, it's not tongue and groove 1x4 fir as is usual for older subfloors. Around this time, it was most typical that they would lay down 1x4 t&g and then tarpaper and 2" wide 5/16" red oak. The t&g sealed the floor from drafts from the basement. If someone didn't want to pay for oak, then the subfloor would be painted. I thought painting the floor would be a quick solution with an older look. But it couldn't be that easy. Nothing else in this house has been easy so why would this be?

Typical subfloor 1x4 Doug Fir Tongue and Groove

In bathrooms, they would use regular 1x8, since the mortar bed would seal the cracks in the boards. We have the second kind of subfloor. 

Also, the original floor tile looks like it's lotsa asbestos. It's over burlap. When I tried to pull up a little piece, it created a little dust storm. We will have to seal it and cover it. 

I'm going to go with some type of marmoleum. It fits the feel of the original floor. 

I think this color would look good and it's on sale for $4/sf in click which would be easy to put down.

Update: nailed it! 

Found the original flooring in the dining area added to the front of the kitchen in '39...

Hard to see but it's like the same stuff but a little darker green with a trim strip. 

This flooring I've chosen is an illustration of how I try to improve and update the house while being respectful of the original style.