Maybe there are other problems with this to consider, like rotted trimmers. My tenants pay rent I provide good housing. I want stuff like this fixed by my guys, that way I know it’s fixed properly.

What the other guy said. The main breaker shuts off everything downstream, but everything upstream of the main breaker in the panel is hot (ie the lugs). And they're pretty easy to hit. You'd have to pull the meter to fully deenergize the enclosure, and that's a pain in the ass to deal with. Generally, you need to call the utility, although you can always break that rule, but pulling meters isn't something I'd recommend to a DIYer because depending on the state of the meter base, there's serious risk of pulling a lug off and arcing it to the can.

Brilliant! Thank you.

It will if they have a disconnect before the panel. That’s how I wired my parents home up, so that they could easily and safely work inside of their main panel if necessary.

If it helps, water in a tube can only be 'vacuumed' up 10.3 meters before a literal vacuum is created. Whereas the distance water can be pushed vertically through the same tube is only limited by the pressure pushing the water. The more pressure, the higher the water goes.

Use plenum rated cable. Resists fire and doesn't release "as toxic" of fumes as regular cable.

What if there is already another cable in the pipe? Will the vacuum/compressed air methods still work?

Sometimes they work great - in my case they do.

I just used a Powerline network adapter kit. That runs through the electrical outlets. I put one in the room where my router is and the other one in my living room to feed my entertainment system. I have a switch in the living room and it is attached to all of the devices including a wireless access point for better wifi signal out there. https://www.amazon.com/gp/product/B01929ESG6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

We use tools to help us pull wire/cable in conduit. The one that would be applicable here would be a steel fish-tape. Something like this, of a sufficient length, would be appropriate: https://www.kleintools.com/catalog/fish-tapes/steel-fish-tape-18-inch-x-50-foot

u/VanillianArt tagging you here so you see it. If you’re going to go this route, PLEASE verify that the conduit doesn’t terminate into an electrical panel. If it does, and the conduit is appropriately grounded the way it should be, you aren’t in much physical danger. However, the fish tape will probably explode inside the panel, causing far more extensive AND expensive repairs than just getting a professional to do the work from the get go.

If the conduit isn’t properly grounded and does terminate into a panel, or is non-metallic (PVC, for instance,) then it the fish tape will essentially turn into an uninsulated wire that you’re holding on to. Definitely not a good time.

One way of checking would be to get a shop vacuum and run it “in reverse” (blow mode) and put it up against the junction box. Go over to the panel, and if you have air coming out of a conduit, it’s a no-go.

I think you’ll probably find that the conduit goes to the panel. Residential electrical doesn’t tend to use conduit for very much at all, except when it’s absolutely required. It would be cheaper and faster to install for the contractor to have just ran plenum-rated Cat5/6/etc cable than to have ran conduit for it. It seems pretty unlikely that they ran spare, future conduits in anything other than a custom home. From my experience building custom homes.

Edit: also, if it’s at all possible, I would recommend completely removing power from the panel in question before removing the cover, and only restoring power after the cover has been replaced. Otherwise, something could go horribly wrong. Even as a professional, taking a dead front off of a live residential panel can be a bit nerve wracking.

Edit 2: a word, for clarity

Source: former electrician of 9 years, with residential, commercial, and industrial experience.

You could probably run Ethernet w/o conduit. It doesn't carry enough electrical current to be a fire hazard in the walls.

If his house is big enough to need a 100m conduit then he can afford to hire an electrician 😁

Conduit normally isn't 1-1/4" or greater in size...

I've got a 2 family house built in 1900. We had this same thing happen in our upstairs apartment the year that we got the house insulated with blown-in insulation. Our tenant told us that his apartment was crying. We went up to look and the walls and windows were dripping. We talked to a couple contractors and they all told us that it's fairly common in older houses when they're "over-insulated", and they all advised us to get a dehumidifier. We got our tenant a dehumidifier and our tenant says he has no more issues with it.

A "mouse" is a foam plug the diameter of the conduit it is intended for. Tie string on and suck thru with vacuum.

A mouse is what you tie to the end of the jetline, to pull the string through the pipe with the vacuum. But more realistically, your apprentice loses the mouse on the first pull and you use the corner of a glad bag from there on out.

And if it’s preterminated, you’re going to need a bigger conduit.

brilliant

I have read most of the answers here and this is how I think you should do this. Not sure what you mean by "open the outlet for that" but I am going to assume you mean a cover plate. You would need a vacuum cleaner where you can move the hose to blow air. Have a friend at one end blow air and you can test if the air is coming through the conduit where you think it should come out. If that works, make a "mouse out of a small wad of crumpled paper, tie it with light string - like cheap kite string and use the vacuum to pull it through the conduit. Use this string to pull a heavier string through until you have a pull rope that will be strong enough to pull your cable. It will probably be easiest to pull from the basement as gravity will be working with you instead of against you, however if the vacuum fits better at the other end use that for string, then you can pull cable either way. Bob's your uncle!

You don't need to run Ethernet through a conduit, you don't need an electrician to run low voltage.

As long as you're fine with patching up whatever holes you make and you don't do something surprisingly dumb, it's an easy DIY.

Won’t help if your metal fish tape pops out and into the supply lugs of the main breaker.

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You never know, that could come in handy.... /s

We had some embedded bolts in our pool deck that were part of an old diving board installation. They laughed at a dremel using heavy duty cut-off wheels. I bought a cheap 4 1/2" angle grinder with cutting discs and it made short work of the bolts.

Using the right tool for the job saves much time and pain. (More recent example: trying to cut some HVAC ducting in-situ between floor joists. Started by trying good quality aviation snips and ended up with a sore wrist before even getting close to finishing one cut. Bought a reciprocating saw and the rest went soo much more smoothly.)

Vacuums with a mouse...? Nozzle autocorrect? Or exciting new terminology to learn??