[tjoiner1986]

I took a few minutes this morning to investigate where the feeder is coming from the ground and entering the garage. It does not appear to be buried in any conduit but I can't verify that without digging up part of the driveway. Judging by the way the feeder is between the concrete slab and the cinder block foundation of the garage, my best guess is that the carport and its concrete slab were added on after the wiring was installed to the garage and that they simply ran the feeder up foundation of the garage and entered through the siding. I could be wrong.

I probed the gap between the carport and garage and took the photo below.

Anyway, I'll see about adding some conduit to protect the exposed portion of the feeder. I'd really like to get the wiring finished so I have power in there again. Once that's completed, I'll revisit the idea of replacing the feeder and the old rubber wiring for the carport lights.

 

[hornetd]

I'm curious about this technique you mention. Feel free to inform me about it.

The National Institute Of Standards And Technology did extensive experimentation on how to more effectively ground existing building to improve resistance to current surge and voltage spike protection of electronics connected to home wiring systems. Should you decide to run a new feeder to the pool equipment you have an easier time to install the system which they devised and tested.

But first find out if your electrical service is already grounded to a Concrete Encased Electrode. Find a bare wire coming out of the meter mains enclosure that ends in a wire or rebar that sticks up out of the foundations footer. If a concrete encased electrode was installed there is no need for additional grounding electrodes.

When the trench for your new conduit is excavated dig the first 28 feet to a depth of 30 or more inches. If it is practical to do so excavate to under the year round deepest water table so that the system would always be discharging into wet earth. [If the lowest water table is 5 feet down I'd call making that trench 5&1/2 inch deep practical. Past that depth I would not.] In the bottom of that 28 feet of trench you would drive 2 ground rods THROUGH THE BOTTOM OF THE TRENCH so that the top of each rod is 30 inches below the final grade. The first rod is driven 8 feet from the foundation. The Second rod is driven 20 feet away from the first in any direction which does no place it closer than 8 feet from any underground structure. It would, of course, be easiest to continue allow the line of the trench for the feeder conduit. The rods are connected to each other and to the bonded bus of the Service Equipment enclosure using #2 AWG copper wire. That wire does not have to be continuous from the furthest rod to the the bonded busbar. You can run a #2 AWG bonding conductor between the rods and a #2 AWG Grounding Electrode Conductor between the closer rod and the bonded busbar of the service equipment enclosure as long as the means used to connect each conductor to the nearest rod is listed for 2 #2 wires or you use 2 single wire connectors. YOU MAY NOT USE ONE ACORN CLAMP FOR 2 WIRES. Acorn clamps are only listed for a single conductor. Those conductors are also run in the bottom of the trench. Once that Grounding Electrode System is installed you back fill the trench up to 2 feet beneath the final grade and install your conduit. With a 2 foot deep trench you will be sure to have the uppermost edge of the conduit at least the 1&1/2 feet below final grade.

To summarize you do one excavation with the first 28 feet, at the meter mains end, deeper than the rest and install the new Grounding Electrode Array at least 30 inches down, backfill to 2 feet deep, install your conduit and backfill the entire trench. Without much additional effort and only a modest additional cost you will have made your home far more resistive to damage to electronic devices powered by the houses wiring. That can save you a fair amount of money and inconvenience should an electric anomaly occur.

Tom Horne

 

[tjoiner1986]

I put in a request this morning to have someone come out and mark the locations of the two buried lines -- the existing 30-amp feeder and the line providing power to the carport -- just in case I decide to upgrade to 100-amp service in the near or distant future. EDIT: I imagine the lines are buried in a straight path from where they leave the basement to the garage but I'd like to know for sure. EDIT #2: They responded quickly and were marking at the house as I left for work. Turns out they only mark public utilities. Finding the lines between the house and garage is up to me.

This first photo is the carport lights and flood light. It transitions from old cable to newer before going underground.

This second photo shows where the feeder line leaves the basement for the garage. Through the window you can see the cars. It's not a big distance. I'll measure it when I get a chance and post that measurement here. That big grey cable above it is the house's main service line. The meter is directly above and outside.

Also, I read up on the "rule of six" relating to disconnecting service and, unless I misunderstood, it seems the NEC now requires a main disconnect to consist of "only one disconnecting means." For me, that "one disconnecting means" is achieved by a 30-amp breaker in the basement of the house (see photo below), however it seems 230.70 states the disconnect must be on the exterior of the garage or inside where the feeder enters. Anyway, with all that being said, I'll need to read up on how to back feed a panel, what size breaker, single or double pole, etc.

Oh and I dropped by Lowe's on my lunch hour yesterday and got a short length of 1/2" conduit to better protect the existing feeder line. I also grabbed a couple of single-gang new work boxes and a 4 11/16" metal junction box with cover plate. Not sure what I'm doing with it yet - either using it to extend the current feeder line to the panel or putting it in the parts bin and getting a different enclosure to put outside the garage to tie the grounds together (if I understood that post #15 right).

Let me again suggest that you use an outdoor wet location box to make that splice. Remember to bond that box, no matter which kind you do end up using, to the Equipment Grounding Conductor of the feeder. Just add a short jumper between the splice inside the box and connect it to the tapped hole that the manufacturer made in the box. That connection must be made with a green screw because the green coating is conductive and will seal the actual contact surfaces from the air thus preventing corrosion. The reason that I'm suggesting that you make the splice outside the building is that the cable has been separated into 2 jacketed conductors with an exposed Equipment Grounding Conductor. The cable must not be separated that way except inside a listed electrical enclosure. Using an exterior box will give you enough undivided cable to reach the raintight cable connector on the outside box. That will allow you enough length past the split to have 6 inches of free conductor inside the box beyond the inside end of the connector and enough length beyond the box opening to do your splicing without being a contortionist. Again the Type NM Non Metallic Cable would come into a clamp screwed into the threaded hole in the back of the box. That prevents any of the NM cable from being exposed to the weather. Run that NM cable up to the panel and terminate it to the line terminals by splicing 2 short jumpers to the energized (Hot) conductor and terminate one of those jumpers to each of the panel's line terminals. Terminate the Grounded Current Carrying Conductor, that is commonly called the neutral even when it is not functioning as one, to the busbar that is already installed in the panel. It is more correct and simpler to say and type to call it the grounded conductor so I do. Add the accessory bus bar to the back wall of the panel's cabinet. Terminate the Equipment Grounding Conductor to that added busbar. If there is a green screw in the original busbar remove it. In buildings supplied by a feeder the Grounded Conductor and the Equipment Grounding Conductor are never connected to each other.

Tom Horne

 

[tjoiner1986]

Note to self: 24 feet between corner of house and front of garage.

Wow, so whoever added these lines really threw caution to the wind. The feeder and carport light lines leave the basement through the foundation walls and are briefly exposed before going underground. I'm sure I've noticed this in the years I've owned the house but didn't know what I was actually seeing until now.

Photo 1 is the feeder line coming out from below the basement window. Photo 2 shows the carport light line coming out from the corner of the house. I mean I don't know much about electrical work, other than the basics, but even I can recognize how shoddy this is.

But first find out if your electrical service is already grounded to a Concrete Encased Electrode. Find a bare wire coming out of the meter mains enclosure that ends in a wire or rebar that sticks up out of the foundations footer. If a concrete encased electrode was installed there is no need for additional grounding electrodes.

Photo 1 also shows two ground rods. This photo was taken directly below the meter.

 

[hornetd]

Note to self: 24 feet between corner of house and front of garage.

Wow, so whoever added these lines really threw caution to the wind. The feeder and carport light lines leave the basement through the foundation walls and are briefly exposed before going underground. I'm sure I've noticed this in the years I've owned the house but didn't know what I was actually seeing until now.

Photo 1 is the feeder line coming out from below the basement window. Photo 2 shows the carport light line coming out from the corner of the house. I mean I don't know much about electrical work, other than the basics, but even I can recognize how shoddy this is.

View attachment 737198

In Photo 1 there are 2 single conductors terminated to separate pipe and rod electrodes. Please trace those 2 Grounding Electrode Conductors (GEC)s and tell us were the other end is connected. The use of galvanized pipe as a driven electrode was once very common but is seldom done in modern practice. Depending on were the GECs fetch up there could be a hazard. On the other hand it may turn out to be nothing. But it is definitely worth checking out.

View attachment 737197

In this second photo there appears to be a cable which comes out of the ground and ends just behind the switch cable. It may be worth knowing how many conductors are in the switch cable and what gauge those wires are. That information is marked on the cable jacket every 2 feet so you have a pretty good chance of finding that mark and telling us character by character exactly what the jacket is marked. Given the availability of wireless and signal over power wire switching this information could turn out to be very helpful to you in bringing power to your garage.

Please also check the cable that has it's energized conductor connected to the 30 ampere single pole breaker which brings power to the shed. Because of a code provision which forbids running 2 circuits to the same building the carport light cable should not enter the garage. That cable could be extended underground using the appropriate splice kit but it would probably be easier to run it into a weather proof exterior box and running it the rest of the way to the car port with Type UF cable run under the eaves of the garage. Regardless of whether you change that pathway or not all of those cables are supposed to be protected from physical damage by being sleeved in rigid conduit from the bottom of the 2 foot 3 inch deep trench to 8 feet above the finished grade. [Finished grade does not include loose aggregate such as gravel nor mulch in any form.] The reason I typed 2 feet 3 inches is that is how deep you dig to get a full 2 foot of earth above the cable. I strongly suspect that the depth of bury of your existing cables will turn out to be shallower than the 2 feet the code required even when your home was built. In your case schedule 40 Rigid PVC Conduit would be code compliant but schedule 80 would be better practice. The price difference isn't much and schedule 80 will stand up better to power trimmers, edgers or any other powered landscaping equipment. If you cable goes from the protective conduit into a box or LB conduit body and enters the building without being exposed above ground on the exterior of the building that definitely fulfills the requirement for physical protection. There are galvanized steel cable guards which can be used to cover the cable from were it comes out of the ground to just above were it enters the building but since those are in far less demand they are more expensive than conduit. The advantage that they offer is that the are shaped like the Greek letter omega Ω although they are not as deep as that would suggest. The guard is fastened to the wall through the flanges which extend outward from its open side so the cable is behind it rather than inside it as it would be in conduit.

The code requires expansion fittings on conduit coming out of the ground to prevent damage from ground movement or the settling of the trench fill but you cables look like they are too short to fit those into the conduit from the finished grade to were the cable enters the building. The exception would be if you bring the carport lighting circuit into compliance with the prohibition against that circuit passing through another structure. If you bring it up the outside wall to the eave to run it outside the building that protection must reach 8 feet above final grade and an exposed PVC conduit that long does need an expansion coupling. I'll wait to hear what you discover about the number and gauge of wires in each cable and were those 2 GECs end up.

Tom Horne

 

[tjoiner1986]

I'll check in just a bit when I take my lunch hour.

 

[tjoiner1986]

In Photo 1 there are 2 single conductors terminated to separate pipe and rod electrodes. Please trace those 2 Grounding Electrode Conductors (GEC)s and tell us were the other end is connected. The use of galvanized pipe as a driven electrode was once very common but is seldom done in modern practice. Depending on were the GECs fetch up there could be a hazard. On the other hand it may turn out to be nothing. But it is definitely worth checking out.

Solid ground rod is for the meter box. Comcast (TV/cable) decided to clamp to the ground wire as well.

The pipe ground is for the phone line.

In this second photo there appears to be a cable which comes out of the ground and ends just behind the switch cable. It may be worth knowing how many conductors are in the switch cable and what gauge those wires are. That information is marked on the cable jacket every 2 feet so you have a pretty good chance of finding that mark and telling us character by character exactly what the jacket is marked. Given the availability of wireless and signal over power wire switching this information could turn out to be very helpful to you in bringing power to your garage.

You're correct that there is an old cable which was cut off just above the ground. This old cable appears to be 2 conductors plus a ground wire but I can't tell what the gauge is. 12 AWG perhaps? It looks similar to the (possibly) natural rubber cable which goes from the breaker box in the basement to a metal junction box, transitions to the newer white cable that then travels under the gravel driveway, enters the garage, enters another junction box, and then transitions back to the old cable which then enters one of two 3-way light switches that control the carport lights - the other switch being in the kitchen.

The newer white cable that goes under the driveway reads "NARAX 12-3 TYPE NM E-15510."

Please also check the cable that has it's energized conductor connected to the 30 ampere single pole breaker which brings power to the shed.

Granted I'm not an electrician but it appears that the line bringing power to the shed (garage, whatever) is double pole. In the photo I posted earlier, it's the breaker in the OFF position marked 10 and 12 just below the other breaker with a red wire (which goes under the master bedroom in case anyone wants to know)

Because of a code provision which forbids running 2 circuits to the same building the carport light cable should not enter the garage. That cable could be extended underground using the appropriate splice kit but it would probably be easier to run it into a weather proof exterior box and running it the rest of the way to the car port with Type UF cable run under the eaves of the garage. Regardless of whether you change that pathway or not all of those cables are supposed to be protected from physical damage by being sleeved in rigid conduit from the bottom of the 2 foot 3 inch deep trench...

Just for clarification, the carport light circuit enters the garage because there is a 2nd 3-way switch (the 1st being in the kitchen inside the house) which also turns the carport lights on and off. This is the switch in the garage with the old, possibly rubber insulated wire that runs in front of the studs and was recommended for replacement in a previous post.

 

[hornetd]

Just for clarification, the carport light circuit enters the garage because there is a 2nd 3-way switch (the 1st being in the kitchen inside the house) which also turns the carport lights on and off. This is the switch in the garage with the old, possibly rubber insulated wire that runs in front of the studs and was recommended for replacement in a previous post.

It is quite common in detached garages built years ago to have only that lighting circuit go to the garage and have a receptacle on that same circuit that is only one when the lights are. The 30 ampere circuit may have been added later. When you wrote "NARAX 12-3 TYPE NM E-15510" did you include all of the marking? I'm wondering if it is 12/3 W GND or 12/2 with ground. It is possible that the oldest cables are without ground but the plastic encased white cable would have a ground I would think. If the black cable which is run across the face of the studs does not have a ground then you need to replace it for the sake of your families safety. All of the 120 volt receptacles in the garage up to 50 ampere 120/240 must be protected with Ground Fault Circuit Interrupters (GFCI)s. There is no wiggle room there. It basically means all receptacles in basements, bathrooms, garages, kitchens, or outdoors must have GFCI protection. Using 1 GFCI receptacle to protect all of the others on that same circuit is usually the most cost effective way to do that. Lighting outlets do not have to be GFCI protected but it does no harm to do so.

Tom Horne

 

[tjoiner1986]

The jacket didn't specify if that "12-3" meant 12-2 plus ground or 12-3 plus ground. Since it's a newer cable, I would think it's "plus ground" but there's no way of knowing for sure without pulling out one of these 3-way switches.

I do have a GFCI outlet in place. No worries there. After the breaker for that circuit, it's the first outlet on a chain of 3 outlets. The lighting will be on a different circuit. And then the flood light will be on a third breaker. I may install a fourth breaker for an exterior outlet in the carport but we'll cross THAT bridge when we get there.

Also, I'm giving more and more consideration to running a new feeder to the garage for full 100 amp service. If I go that route, do I need 2-2-4 or 2-2-2-4 aluminum wire? EDIT: Nevermind. I read that 2 hots are required for a subpanel. So 2-2-2-4 it is.

 

[tjoiner1986]

You might not want to use 240v but most (all?) breaker boxes are designed so that each hot leg powers alternate breakers. Check the label that is on the side of that box.

I should have done this at the beginning of this thread but here is the box I'm working with. It is a Square D QO612L100SCP. Judging by the diagram on the label, it looks to me like you're correct about each leg powering every other breaker.

This is the cable I was thinking of using for this project. It's Southwire 2-2-2-4 URD rated for direct burial and good for at least 115 amps. After measuring the distance between the house and garage, I think 100 feet is plenty.

After doing a bit more research, I read that a subpanel's feeder line gets derated and that #2 aluminum cable is limited to 80 amps. I'm perfectly OK with that. I highly, highly doubt I will ever pull 80 amps through this line. Later, I read that SER cable is the proper stuff to use so I'm a little stumped there. My understanding is SER is not rated for direct burial and must be run through conduit.

Below these first two photos is a third one showing the front of the garage. Overlook how weathered it is. Repainting the house and garage is happening once we get some other things done first. Immediately on the other side of this little bit of wall (in the center of the photo) next to the door is where the carport light circuit enters. I was thinking IF I do decide to replace the feeder, I could come up on the outside of the garage, beside the door, using conduit and the proper mounted weatherproof enclosure, enter the small section of wall beside the door, and continue on through the studs until I reach the subpanel.

 

[lenaitch]

I'll let the pros/Code guys comment, but, personally, I would run individual conductors in conduit rather than do direct wire. You have to dig a trench either way.

 

[Jim Port]

Conduit is not needed for SER. SER cannot be buried.

 

[tjoiner1986]

I'll let the pros/code guys comment, but, personally, I would run individual conductors in conduit rather than do direct wire. You have to dig a trench either way.

Oh absolutely. If I'm going to redo the feeder then I'd like to do a little more than is required. I'm also using this as a learning experience. My wife and I have been wanting to turn a shipping container into a small home for a while now. I'll need to know all this stuff when we get to that point.

Conduit is not needed for SER. SER cannot be buried.

Sounds like I'll be using the URD stuff then. 👍 Thanks for the info about SER.

 

[tjoiner1986]

Since my last post, I shifted focus from rewiring to getting the sheathing up so I can finish the workbench and get my tools off the floor and have more space to work.

With that completed, I suppose it's time to shift back to electrical. I'm thinking of taking the plunge and ordering 80 feet of cable (should be enough). The question now is how on earth to run it from the main box and out the basement.

Here's a photo of the main box in all it's admittedly messy glory. Honestly, I can't wait to get out of this house but for now I'm stuck with it and have to work with what I've got.

Maybe it's because I'm not an electrician for a living but I'm thinking PVC conduit out the bottom, run it to the right so it rests atop the unfinished basement walls (there's basically a ledge of earth along the perimeter of the basement) and along the block wall foundation, then exit below the foundation and onward to the garage.

 

[hornetd]

Since my last post, I shifted focus from rewiring to getting the sheathing up so I can finish the workbench and get my tools off the floor and have more space to work.

With that completed, I suppose it's time to shift back to electrical. I'm thinking of taking the plunge and ordering 80 feet of cable (should be enough). The question now is how on earth to run it from the main box and out the basement.

Here's a photo of the main box in all it's admittedly messy glory. Honestly, I can't wait to get out of this house but for now I'm stuck with it and have to work with what I've got.

Maybe it's because I'm not an electrician for a living but I'm thinking PVC conduit out the bottom, run it to the right so it rests atop the unfinished basement walls (there's basically a ledge of earth along the perimeter of the basement) and along the block wall foundation, then exit below the foundation and onward to the garage.

View attachment 740894

Somewhere along this thread I got it into my head that you have a Meter Mains assembly that includes both the meter socked and a main breaker which serves as the Service Disconnecting Means. While going over the postings again I realized that I cannot now find any solid indication of that. Is there a main breaker, switch, or fused pullout in the same enclosure as the meter socket? Like these

It would have a separate compartment for the main breaker as these 2 do.

This only going to be a partial list of the things you will need to address to make this main panel minimally safe, although nowhere near code compliant. First you will need to answer a couple of questions.

• Am I correct in concluding that this is a dug out basement with the lower walls and floor of earth?
• Is that panel hanging from the joist?
• Are you willing to put in the work to construct a proper support for it?
  • For someone inexperienced at dealing with the materials that I would suggest you would be looking at a full day of or work to do that.
• Will the panel's height fit between the joists and the ledge?
• How long is that Service Entry Cable, in wire feet, from were is comes out of the wall to were it enters the panel's enclosure?

I would strongly suggest that you address the most serious problems with this panel BEFORE you try to run the feeder to the garage because if you install the garage feeder prior to doing the most basic corrections to this Service Equipment you will be making the situation worse and when you go to sell the house it's present condition would be a huge RED Flag to the buyer's home inspector. The buyer will justifiably demand that the service be rebuilt from scratch. All of the necessary work is doable by you with a little bit of patience and some careful work. It won't even be physically hard to do.

Tom Horne

 

[hornetd]

I thought of something just now while I was outside walking our dog -- part of the feeder wire is visible outside the garage. That's a bit of weathered canned foam poking out. The concrete you see is the carport slab. It's covered by a roof. Why this is the way it is, with a portion of the siding cut out, is beyond me.

View attachment 736863

You might want to cover the cable and the gap in the siding with a 4&11/16 square cover which looks like this

and not like this

The open edged slots are too easy to dislodge from the fasteners.
Paint it well on both sides to prevent rusting. Ask in a paint store; rather than a Big Box Store; for a paint to cover galvanized metal. I would GUESS that might be some version of Rust-Oleum spray paint. Paint both sides of the plate before installing it. That will provide physical protection to the exposed cable including from critters in search of nesting materials who may chew on the jacket unless it is the hard plastic type.

If you are willing to do so please provide a photograph of the carport roof's underside and framing. I have an idea that you might like.

Tom Horne

 

[hornetd]

Those individual wires actually appear to have originally been insulated together, along with the ground wire, to form a cable that looks similar to Romex. Like, imagine Romex if it were a solid insulated cable rather than sheathed.

The cable you describe is called Underground Feeder cable, Cable Type UF. It is suitable for direct burial in a trench that is at least 2 feet deep to the top of the cable.

Tom Horne

 

[CrossConnect]

You don't want to leave that circuit as it is. It is subject to physical damage. That wasn't code compliant in 1940 so it is not grandfathered now. The minimum that should be done with that cable is to move it up to the Inside edge of the top plate of the wall so that it will not end up with hand cultivators or anything else hanging off it nor leaning on it.

Tom,
You gave excellent advice as always, but is that wire even code compliant to be in there in the first place? He states it's a detached garage, and the wire is used to control what appears to be a 3 way light switch, the other switch located in the house.

Doesn't that break the single circuit/feeder to a building rule?

 

[hornetd]

1 also shows two ground rods. This photo was taken directly below the meter.

For US National Electric Code purposes these electrodes do not meet the requirement for 2 driven rod or pipe electrodes spaced a minimum of 6 feet apart. The galvanized rod is fine for the first driven rod electrode although it would need to be driven all the way into the ground to be code compliant. Viz.
250.53 Grounding Electrode System Installation.
(A) Rod, Pipe, and Plate Electrodes. Rod, pipe, and plate electrodes shall meet the requirements of 250.53(A)(1) through (A)(3).
(3) Supplemental Electrode. If multiple rod, pipe, or plate electrodes are installed to meet the requirements of this section, they shall not be less than 1.8 m (6 ft) apart.

Informational Note: The paralleling efficiency of rods is increased by spacing them twice the length of the longest rod.
[Informational notes are not enforceable provisions of the code. They are often used, as here, to inform the user of a better practice than the minimum required by the US NEC.]

(G) Rod and Pipe Electrodes. The electrode shall be installed such that at least 2.44 m (8 ft) of length is in contact with the soil. It shall be driven to a depth of not less than 2.44 m (8 ft) except that, where rock bottom is encountered, the electrode shall be driven at an oblique angle not to exceed 45 degrees from the vertical or, where rock bottom is encountered at an angle up to 45 degrees, the electrode shall be permitted to be buried in a trench that is at least 750 mm (30 in.) deep. The upper end of the electrode shall be flush with or below ground level unless the above ground end and the grounding electrode conductor attachment are protected against physical damage as specified in 250.10.

Tom Horne

 

[CrossConnect]

Sounds like I'll be using the URD stuff then. 👍 Thanks for the info about SER.

It's my understanding you can not use URD after the meter. URD is not rated for indoor use. You'll need to use MHF 2-2-2-6 in conduit inside. in conduit or direct burial outside.

People also think they can put 100A on #2AL, You can't, it's only rated for 90.