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House built in the 50’s has an old fuse box that is being used to power lights and outlets in one of the barns on the property. The fuse box in this barn is fed from a 60 amp breaker at the meter. The meter socket was installed 2 years ago. The breaker box at the meter has a 100amp breaker for my house, and a 60amp breaker to the barn. My question(s) is can I replace the fuse box with a load center? And is this even considered a subpanel since it does not come off of the main panel in the house? Thanks in advance.

Breaker at Meter

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Fuse Box in Barn

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    Is the meter on a pole, at the house, or at the barn? Are the feeders from the meter box to the house and barn panels 3-wire or 4-wire? Can you provide photos of the inside of the fuse box (with the breaker at the meter off, of course)? – ThreePhaseEel Aug 24 '19 at 15:09
  • Thank you very much for the reply. I will Take the pictures as soon as I am home and post them. Thank you again. – Steelermako Aug 24 '19 at 16:26
  • ThreePhaseEel - I have several barns on the property and the meter is on a pole between all the barns and the house. It it’s probably 3’ from the barn with the fuse box that I have the questions about. The feeders appear to be two wire. I have attached the photos you requested. Any help would be appreciated. – Steelermako Aug 24 '19 at 21:10
  • Well, I apologize I thought I could just copy and paste the photos here but apparently I cannot, and I'm having trouble finding any way to attach the photos. – Steelermako Aug 24 '19 at 21:39
  • The panel on the pole is actually your main panel the one in the house and barns are sub panels of this panel. Can you update it sure it will make resetting a circuit easier and safer since many times the wrong size fuse is used with a breaker just turn it off all the way then back on but you already know that. Just to recap the breakers at the pole are the mains and the ones in the house and barn are sub panels. – Ed Beal Aug 24 '19 at 21:42
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You'll need to stuff a ground wire down that conduit first

The first order of business in this job is to get a ground wire down that conduit to the barn. You'll need several feet of 8AWG bare stranded copper for this, with one end going to the combination N/G bar in the pole panel, and the other end left hanging in the barn panel for now. (You'll also want to turn the main breaker at the pole off while doing this pull.) Don't worry about conduit fill, by the way: a 1.25" Schedule 40 PVC conduit supplies about twice as much fill as you'll need for everything here.

Then you can replace the barn panel with something modern

Once you have a ground wire in the conduit and hooked up to the main panel, you can then replace the subpanel in the barn with a modern breaker box. I recommend a 100A, 24-space, main breaker panel as a minimum for this application; the main breaker here simply serves as a local shutoff means for power to the barn, so it can be larger than the feeder breaker without causing any issues, and slots are cheap to buy now when you're changing the panel out anyway but rather expensive to add later. Also, make sure to fit the panel with separate ground bars if it doesn't come with them fitted from the factory, and to pull the (usually green) bonding screw from the panel's neutral assembly so that it's configured properly as a subpanel.

And the barn will need ground rods, too

While you're working on the barn, you'll need to drive a couple of 8' ground rods 8' apart and use more of that 8AWG bare copper to connect both ground rods to the barn subpanel. This takes care of the other side of grounding the barn; the ground wire to the main panel returns wayward utility electricity back to the utility, while the ground rods return wayward natural electricity (such as lightning-induced transients or even just static charges) back to terra firma.

Torque matters!

One more thing is that you'll want to use an inch-pound torque wrench and/or torque screwdriver when making up the lug connections on breakers and loadcenters so that you tighten the screws to the labeled specification torques; this is required by 2017 NEC 110.14(D), and is a good idea anyway lest a bad connection in your electrical system slow your roll.

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  • that’s exactly the info I was looking for. Thank you. I have purchased the ground wire and the replacement panel only to find that the feeder wires were left with too little excess to reach the new connection points. Is there a legitimate way to splice these to extend them Of should I just remove them and run new cables? It’s only approx 15 feet in distance accounting for underground conduit length from barn to meter at pole. – Steelermako Sep 2 '19 at 13:15
  • @Steelermako you can use some insulated mechanical lugs ("Polaris connectors") to splice some extra wire onto the feeder, although for that short of a run, it might be cheaper to simply replace them. Also, we thank people around here by upvoting and/or accepting their answers :) – ThreePhaseEel Sep 2 '19 at 13:28
  • I think I upvoted and accepted your answer. I hope I did anyway - I’m new here. I haven’t been able to find #8 bare stranded locally - I live in the sticks would #8 green insulated be acceptable? Also since I will be taking your advise to replace the cable from the pole/panel instead of splicing. #4 copper is the correct cable for this I believe. Please correct me if I’m wrong. – Steelermako Sep 14 '19 at 20:53
  • @Steelermako -- #4 aluminum is fine for 60A when landing on 75degC lugs such as in your scenario here, and #8 green THHN will work for the ground wire (I just prefer bare as it uses less fill). – ThreePhaseEel Sep 14 '19 at 23:57

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