2020 NEC requirement for outdoor disconnect on 1 or two family dwelling units.

[kwired]

I prefer them for my safety and convenience. If I had disconnects before the CT metering installation, I wouldn’t have to take out an entire building for maintenance, or to disconnect this business if need be for something as simple as they shut down.

Even if I have my service disconnect near the CT meter, which I do commonly have on larger services on some farm operations or other outdoor specific load installations, POCO's here have it load side of metering - they don't want customer access to non metered conductors. Nearly all those situations the transformer supplies a single service and killing the transformer isn't a big deal as it doesn't effect other customers. If they need to disconnect the meter itself while servicing it, there are bypass components within the meter socket.

A service disconnect ahead of CT's or even after if all you want is no current thru the CT's when working on them is still taking the entire service down when you open it:?

 

[Hv&Lv]

Even if I have my service disconnect near the CT meter, which I do commonly have on larger services on some farm operations or other outdoor specific load installations, POCO's here have it load side of metering - they don't want customer access to non metered conductors. Nearly all those situations the transformer supplies a single service and killing the transformer isn't a big deal as it doesn't effect other customers. If they need to disconnect the meter itself while servicing it, there are bypass components within the meter socket.

A service disconnect ahead of CT's or even after if all you want is no current thru the CT's when working on them is still taking the entire service down when you open it:?

Sorry, I didn’t proofread correctly.... Trying to do this on a iPhone is aggravating...
My statement should have read, “before or after”.
I deleted some typing and went too far back.

I don’t really care about current through the CTs. I can shunt them out for metering wiring maintenance, testing,or pull shunt blades for the meter.
What if I need to change them, or change a service.
Everywhere is different..
I have one installation here where a 750kVA feeds a small mall. About 18-20 businesses.

Lets say you want to rewire one of these businesses for a different business with different electrical requirements.
The conductors go to the CT “cabinet” which has been in for years, and is really a 12X12X 96 trough rather than a 30X30 CT cabinet, where they are connected to your conductors going to your panel(s)
you call and say you need the service disconnected so you can change everything.
Here if the disconnect was before the trough life would be real easy.

I disconnect it hot? I can, and have, but with the new AF requirements, our rules are nothing over a 150 kVA hot to minimize AF.
so, I come in, shut the entire installation down in the wee hours in the AM to minimize disruption. Again, a disconnect on the line side would solve this.
Its not required, not our equipment, but it takes a lot of aggravation out of it.

We have a couple of installations where they have this setup. We did require it of at least two property’s (strip malls) because it seemed like they changed electrical every time they changed tenants, which seemed like every year or two...

For a 30X30 CT cabinet like we all have installed, a disconnect would be great on either side.

 

[kwired]

Sorry, I didn’t proofread correctly.... Trying to do this on a iPhone is aggravating...
My statement should have read, “before or after”.
I deleted some typing and went too far back.

I don’t really care about current through the CTs. I can shunt them out for metering wiring maintenance, testing,or pull shunt blades for the meter.
What if I need to change them, or change a service.
Everywhere is different..
I have one installation here where a 750kVA feeds a small mall. About 18-20 businesses.

Lets say you want to rewire one of these businesses for a different business with different electrical requirements.
The conductors go to the CT “cabinet” which has been in for years, and is really a 12X12X 96 trough rather than a 30X30 CT cabinet, where they are connected to your conductors going to your panel(s)
you call and say you need the service disconnected so you can change everything.
Here if the disconnect was before the trough life would be real easy.

I disconnect it hot? I can, and have, but with the new AF requirements, our rules are nothing over a 150 kVA hot to minimize AF.
so, I come in, shut the entire installation down in the wee hours in the AM to minimize disruption. Again, a disconnect on the line side would solve this.
Its not required, not our equipment, but it takes a lot of aggravation out of it.

We have a couple of installations where they have this setup. We did require it of at least two property’s (strip malls) because it seemed like they changed electrical every time they changed tenants, which seemed like every year or two...

For a 30X30 CT cabinet like we all have installed, a disconnect would be great on either side.

Nothing wrong with POCO requiring said disconnect or you get no service, if they want to do that. Why does NEC need to require it?

 

[Hv&Lv]

Nothing wrong with POCO requiring said disconnect or you get no service, if they want to do that. Why does NEC need to require it?

Then we wouldn’t have to listen to so much whining...:rotflmao:

 

[Frank DuVal]

I can't remember if I've ever seen a main disco not outside at the service entrance, usually as a meter/main combo panel like this:

You're not from around here, are ya?

And I speak from many populated areas here in VA, NC, MD...... Never used around here unless cable length inside building to main panel makes outside disconnect mandatory.

Salt, humidity and outside metal are not a good match.

For an example, just see this other current thread:

https://forums.mikeholt.com/forum/a...these-wires-water-damage-or-joule-heating-etc

 

[hbiss]

I must admit being surprised by this. I would think a Vo-Tec should be the FIRST to implement teaching the new methods that will be coming out, even if years down the road. It will be years before their students are the journeymen in the field, and that shouldn't be the first time they have to adapt to the new methods and products.

They do it just like we do it. Ever hear of continuing education?? Students need to learn what they need to know for the job they will be doing when they get done with tech school. Covering code changes for, in some cases four cycles beyond what they will be using is only going to be confusing and almost certainly forgotten. Hell, I can't keep the AFCI crap straight when someone asks a question here. I only know what the 2014 code requires because that's what we use.

Most states require some kind of continuing education and that is where you learn about the changes when your state adopts a new code cycle. Don't worry about it until then.

As noted, the manufacturers are already geared up and making these products. They are the way it is done in much of the country. I can't remember if I've ever seen a main disco not outside at the service entrance, usually as a meter/main combo panel...

Yeah, in much of the country. I don't know where you get your information from. Like I said, panels don't belong outside. And I've never seen an outdoor disconnect that didn't have to be there.

-Hal

 

[kwired]

They do it just like we do it. Ever hear of continuing education?? Students need to learn what they need to know for the job they will be doing when they get done with tech school. Covering code changes for, in some cases four cycles beyond what they will be using is only going to be confusing and almost certainly forgotten. Hell, I can't keep the AFCI crap straight when someone asks a question here. I only know what the 2014 code requires because that's what we use.

Most states require some kind of continuing education and that is where you learn about the changes when your state adopts a new code cycle. Don't worry about it until then.



Yeah, in much of the country. I don't know where you get your information from. Like I said, panels don't belong outside. And I've never seen an outdoor disconnect that didn't have to be there.

-Hal

As far as a schooling for electricians and which code should be taught, not all students will end up working in the same state they went to school in. That said, many probably still teach whatever is current where they are located. I know what was and probably still is typical for the school I went to - they likely try to modify courses and won't hit code too hard this fall semester simply because 2020 wasn't available when the semester started, but likely will start hitting code classes when next semester starts in January with the 2020 NEC. It likely won't be law in this state until sometime between May and August though. Because it is in State statutes is has to go through legislation before it becomes law, and even then won't ordinarily go into effect until 90 days after, not sure if that is 90 days after it is passed or 90 days after legislative session ends. It usually passes, but there are other bills that are higher priority and you just don't know when it will go through the process.

 

[hbiss]

As far as a schooling for electricians and which code should be taught, not all students will end up working in the same state they went to school in.

I'll even go so far as saying that teaching a particular code is a moot point. The important thing for a student is they need to master how the Code is arranged, what it covers, where to find things and how to interpret what's written. So using a current Code will do that. Once they have that concept down, they should be smart enough to understand the inevitable Code changes that affect their work.

If I were paying for a vocational school, I would want to learn what I need to know to get a job after I'm done, along with a solid understanding of the industry. After that it's on the job training. I don't want to pay someone to waste my time with things I won't see for years if ever. If I need to, I can figure those out myself if you've given me the tools to do so. So teach how to read and understand the Code, not what it says.

-Hal

 

[brantmacga]

Can someone please give me a manufacturer and model number or numbers?

For exterior disconnects on residential I use the Square D QOM2 enclosure with appropriately sized breaker, and a main-lug loadcenter inside.

Any supply house around you should have something similar as there are many installs that currently require a disconnect.


Sent from my iPhone using Tapatalk

 

[PaulMmn]

For exterior disconnects on residential I use the Square D QOM2 enclosure with appropriately sized breaker, and a main-lug loadcenter inside.

Any supply house around you should have something similar as there are many installs that currently require a disconnect.


Sent from my iPhone using Tapatalk

Why a main-lug loadcenter inside? I realize another breaker inside is redundant (and if the same rating as the one outside, you may have to hunt for the one that tripped), but if you're working on the panel I'd think it would be more convenient to -know- that power was off without having to lock out the outside breaker.

"Take my money, and give me what I want!"

 

[ActionDave]

I don't know why so many people get their panties in a wad about MLO panels.

 

[brantmacga]

Why a main-lug loadcenter inside?

Money. If someone wants it I’ll install it, but I don’t see it as a necessary expense.


Sent from my iPhone using Tapatalk

 

[PaulMmn]

If DIY electricians don't understand how it's wired, we could have a lot fewer DIY electricians!

 

[MAC702]

... Ever hear of continuing education?? ...Don't worry about it until then.

Sometimes I see a new code coming that I like. It happens. I'll start doing it as soon as feasible. Regardless, I like to know what's coming. Your mileage obviously varies.

... I don't know where you get your information from...

Working on them everyday, in a different part of the country than you.

 

[hbiss]

Sometimes I see a new code coming that I like. It happens. I'll start doing it as soon as feasible. Regardless, I like to know what's coming. Your mileage obviously varies.

If a new Code hasn't been officially adopted into law, doing things according to it can be a violation in many cases or at least cause the customer unnecessary cost. Doesn't matter if you like something or not, not up to you.

-Hal

 

[MAC702]

If a new Code hasn't been officially adopted into law, doing things according to it can be a violation in many cases or at least cause the customer unnecessary cost. Doesn't matter if you like something or not, not up to you.

I did not imply I'd ram it down a customer's throat. I like knowing things and having options. Your mileage may vary.

 

[norcal]

Outside panels have the norm in CA for 50+ years, this Cutler-Hammer panel has been in place for 24 years, another 200A ITE panel on the same property will have been in service 40 years, in 2020, chose this photo because it's handy & know how long it's been in service.

 

[hbiss]

Want to see the meter pan on my house after 30 years?

-Hal

 

[hornetd]

Isn't locking them going to defeat the purpose? What are first responders supposed to do, ask you for the key or get out the bolt cutters? Might as well just pull the meter or cut the drop.

Did anybody even get input from first responders to find out the number of times they felt they had to cut power before attacking the fire? Fires I've seen were almost out before the POCO came to cut power.

-Hal

Hal

I served 45 year as a Firefighter EMT. Every riding position on the apparatus had assigned initial duties to perform. Barring situations were the unit's Officer In Charge (OIC) has to redirect the firefighters on the unit to a more urgent task, one of the default assigned roles is Utility Control. That includes shutting off any outside liquid or gaseous fuel source and opening the main breaker of the service equipment. The Utility Control Firefighter also searches the floor were the Service Equipment is located as soon as the Power was shut off. When that firefighter dismounted they already had a hydraulic lock breaker (Hydra Ram), Irons; this is a flat head axe and a "Halligan bar" prying tool; and the short bolt cutters in order to be able to force entry into the portion of the structure were the utility controls were located. I filled that role many times because the officers trusted me to know what the main disconnect is since I was a working electrician.

Therein lay the source of my antipathy to what the Fire Investigators wanted us to do. The always harped on only opening the Main Breaker so as not to disturb a tripped breaker which might help determine the "Cause and Origin" of the initial ignition. I kept pushing right back at them saying that what made up the Service Disconnecting Means is often less obvious than they assumed. I wanted the Utility Control Firefighter to open every single disconnect and circuit breaker that they could find. A smoke filled basement with low visibility is no place to try to figure out which breakers were the "Main."

The housing stock in our service demand area; which firefighters call their "First Due Area;" was mostly older than 50 years. We have a lot of fused pullouts as the Service Disconnecting Means and far more split bus panels than a newer built area would have. We even have a fair number of Sears, Roebuck and Company kit homes with the numbering on the structural lumber still visible in the basements and attics. Most of those are still wired with knob and tube. Some of the panels in our first due area were assembled from parts into a cabinet that had been made by the carpenters. The electricians would then line them with asbestos sheeting and build the panel board inside that cabinet. We also have some converted DC trolley power 600 volt panels which have fuses in all of the neutrals. Keep in mind that there is no legally enforceable mechanism to force any of the owners to upgrade these relics from the dawn of electrical use in dwellings.

On the one hand I like the idea of an external disconnect of some kind for the safety of Firefighters. But it will take many decades for the existing houses to be replaced or modified sufficiently to force the electrical to be brought up to present code. On the other hand our area has had a steady growth in Home Invasion robberies and I can understand the concerns occupants have about having an electrical disconnect outside of the home.

The region's telephone service provider convinced the Public Service Commission to remove the requirement for the telephone Customer Service Unit to have battery backup with the batteries maintained by the service provider. They do not even have to provide the initial back up battery now. Since the provider is now changing all service to fiber optic lines, loss of utility power cuts off telephone service to all affected premises. So you want to invade a home and hold the spouse and or children hostage so that the other spouse will withdraw the family's life savings and give it to the robbers step one is to cut off the power to disable the fiber optic telephone service and make the occupants come outside to restore power.

I sure hope that a power outage is not caused by, say, an ice storm which destroys the antennas on most cell towers and pulls down all of the aerial fiber which connects them to the Public Switched Telephone Network. Ice Storms are the most frequently occurring weather disasters in this region.

[/RANT] = Rant mode off.

--
Tom Horne

 

[hornetd]

they open it @ the pole either way.....~RJ~

Yes but it is the POCO that does that here. They only do that after pulling the meter which firefighters in this area do not do. They usually don't arrive until after the fire is under control and we are in the overhaul stage of searching for any hidden fire. After that we can move on to "mop up," including water removal and smoke damage mitigation. (I seriously despise WaterVacs. they are a brand of backpack "Water Vacuum" that have a capacity of 8 gallons. At 8.34 pounds per gallon they weigh almost 100 pounds when full.)