How do I have to run the SER cables from the original hole(where the SER cable goes through the wall) to the side of the new panel?

Can SER cable be exposed or needs to be inside a conduit? Conduit type? AFAIK I can not use EMT, the city inspector says that, and she is not very friendly on providing such information.

enter image description here

Edit/Update: Here is the entire picture of old and new panel enter image description here

EDIT about Service cable entrance enter image description here

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    What's on the other side of that wall? say the meter...say the meter... Jun 13, 2019 at 1:10
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    The opposite side of the old panel back to back is the meter.
    – cadobe
    Jun 13, 2019 at 1:18
  • Fantastic. Are you planning to entirely remove the old Zinsco panel on Cutover Day? Jun 13, 2019 at 1:32
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    Also, where does the white wire that enters via the bottom left of the old panel go to? Jun 13, 2019 at 3:13
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    @Robert Above the panel I will make that section removable with few screws, just in case later I need to add some more circuits. I wonder if the rigid nipple between the panel and meter(they are back to back) can be Schedule 40/80 ?
    – cadobe
    Jun 13, 2019 at 19:37

2 Answers 2


I see where there is a cripple wall or something preventing you from fitting the new taller panel where the Zinsco had been.

Well first, I would go back to the drawing board and see if I could find a panel that fits inside the space the old Zinsco is coming out of. However your first priority is a whole lot of spaces, so I would only bother looking at CH or QO, since they put 40 spaces where other panels only put 30. In this day and age, you want 40.

If you just can't find a 40 that fits there at sane price, then continue with your original plan.

I presume you've considered laying a piece of plywood atop the pictured joists where the Zinsco was, with the new panel's entry hole lined up perfect with the conduit nipple, and extending the nipple as needed. I can see where that would create an access problem for one conduit entry at the bottom. Okay.

I consider the idea of using exposed flexible cable to be beneath discussion. It is on the wrong side of the main breaker, if it got hit with something, nothing would stop the arc fire. The bend would be freakish and very, very hard. You need XHHW single conductors just to make this DIY doable, and that needs conduit.

But that's no big.

Oh? She doesn't want EMT? Alrighty then... use RIGID. Realistically, you will need a conduit body to turn that corner anyway. That leaves only about 3 inches to go with actual conduit. Rigid is pricey stuff, but that doesn't matter for 3 inches.

enter image description here

When you tear out that ZINSCO panel, there will be a "pipe nut" that you unwind with a hammer and screwdriver. Once the panel is out, underneath that is probably a Rigid pipe nipple (a nipple is a short pipe) with pipe threads. Test fit the conduit body and see how much distance you need. You either replace that nipple with a longer one, or add a coupler and a short nipple to reach the conduit body, depending on what is practicable.

With Rigid conduit, you go to a competent hardware store who cuts and threads pipe (and shoplifters), and buy the right length and have them thread it.

Now, the only other risk is that the conduit body is so wide that it forces the new panel to the left. Could be. If that knocks it off the joists, get a sheet of 3/4” plywood about 33.5" (or wide enough to span 3 joists and 2 spaces) x the height of the new panel + 6”.

Then, you will need to account for the thickness of the plywood in the above nipple. So test fit everything first!

Then, you use appropriate sized XHHW wire. If the price of copper wire gives you pause, use aluminum wire 2 sizes larger. All 100A+ terminals are designed for aluminum wire and have aluminum lugs.

Remember, this is a whole domicile service, so you get the 83% favorable derate from NEC 310.15B7.

  • Yes indeed. The first option I think is the best one. Economical and work wise.
    – cadobe
    Jun 13, 2019 at 14:43
  • This hole thing is based on ,if he needs SER or SEU. Main or sub- panel. Or did code change ?
    – user101687
    Jun 13, 2019 at 16:29
  • AFAIK SER is used when cables run from the roof/outside and SEU is used mainly buried. My case the mast penetrate the roof going down the wall.
    – cadobe
    Jun 13, 2019 at 19:39
  • Seu is used for riser ,and going to panel has been for years .thats why the have to sill seal,to protect it to keep water out.
    – user101687
    Jun 13, 2019 at 20:14
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    Well you know I'm captain conduit :) I like conduit because it's legacy and so there may be a code issue with hork-a-dorking some cable through the conduit gap; because conduit is safer and provides a ground path; and because individual XHHW wires will be much easier for a novice to wrangle. Jun 13, 2019 at 20:18

Many ways to do this. First, is this the main panel? If so, SEU is the wire needed. Two hots And a ground.

If you have a meter main, or breaker outside, then the panel is a sub-panel and you need 4 wire ser. I don't see why you can not nipple through meter into panel. And remove the short studs in the way. Use pvc as it's a little easier to work with.

SEU is allowed and is done all the time without conduit. Just have to watch length of wire. And you could sleeve it to protect or not.

Make sure you bond the panel if a main, which should come with bond screw, or you have to get ground bar to add to panel and not bond panel. White or neutral to bar on panel. Bare grounds to added ground bar. Also check the ground rods . and wire to them.

If this the main panel run water bond to it. If sub-panel water bond goes to meter main outside.Cover hole bay with plywood, screw on so easy to add wires later. And mark the ground wire, green tape or bare. By doing this you do not have to run cable in conduit. Only were they are open in the garage which should be done where they come down to outlets or switches. Up high on joist is ok as long as nothing stored up there.

  • Can you take a look to the last image on my question? What type of cables are those? The panel is Main panel. Why should I use SEU since SEU stands for "Service Entrance Underground Cable"? The panel is 200 Amps so I need to go with AL 4/0-4/0-4/0-2/0 right?
    – cadobe
    Jun 13, 2019 at 20:40
  • Yes not .Ser if that is main panel..Or copper or alum. Wires if going through pipe or nipples. Wire cable not needed..
    – user101687
    Jun 13, 2019 at 20:43
  • They are single wires. Not a Seu cable going through a close nipple .The way you should do it.
    – user101687
    Jun 13, 2019 at 20:55
  • I have seen pipe jump on shorts and fitting loosen up'There goes path to ground. Code plus pull ground wire.
    – user101687
    Jun 13, 2019 at 21:37
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    @RobertMoody I would never fault someone throwing a ground wire in the pipe. Belt and suspenders. Especially if there's any chance of the pipe getting banged up. Just had one of those with an A/C unit run... steel wire holding a duct broke, laid on the conduit, separated the joint ... I fixed it but then, a jackass tried to steal the A/c unit with the power on, broke the conduit ground path at the unit, grounded a hot and got a hell of a shock... decided not to steal it after all. I'm not running a ground wire there lol! Jun 13, 2019 at 22:13

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