# Triplex



## WronGun (Oct 18, 2013)

Anyone ever tell you , you can't use triplex ? Because the N has to be same size as lines? Someone not very reliable mentioned this to me , just trying to verify this 


Sent from my iPhone using Tapatalk


----------



## The_Modifier (Oct 24, 2009)

Did they happen to cite a code rule?
We Use it all the time here in Ontario.


----------



## sbrn33 (Mar 15, 2007)

The N is the same size in triplex. Are you talking about URD? Triplex is overhead in my book. Plus most times you can derate the neutral anyway.


----------



## 99cents (Aug 20, 2012)

Someone should write a code book of pretend rules, except nobody would read that one either.


----------



## HackWork (Oct 2, 2009)

Yeah, what exactly do you mean by triplex and what situation is it in?

When I think of triplex, I generally think of 2 insulated conductors around an ACSR guy wire for overhead use.


----------



## WronGun (Oct 18, 2013)

Neutral is smaller


Sent from my iPhone using Tapatalk


----------



## Signal1 (Feb 10, 2016)

Looks like URD to me 4/0-4/0-2/0? Maybe some people call that triplex?

More details as to how you are using this would be helpful.


----------



## WronGun (Oct 18, 2013)

It's for service , my supplier has it In stock 4/0-4/0-4/0 , I'm going with that. I don't know why but I see an inspector busting my balls someday for the smaller neutral... covering my ass


Sent from my iPhone using Tapatalk


----------



## Going_Commando (Oct 1, 2011)

Load calc it. I bet you are nowhere near 200A, so the nuetral is fine. In the NEC you can go 2 sizes down on the nuetral if your load calc allows, and I assume the CEC is the same.


----------



## HackWork (Oct 2, 2009)

I believe that is what some people call "Sweet Briar".

I install 200A services all the time, I use 4/0 for the hots and 2/0 for the neutral. When I do load calcs I always see that I can use much smaller, so I may start using 1/0 for the neutral.

I have never had an inspector say a thing about it, nor do I expect one to.


----------



## ponyboy (Nov 18, 2012)

HackWork said:


> I believe that is what some people call "Sweet Briar".
> 
> I install 200A services all the time, I use 4/0 for the hots and 2/0 for the neutral. When I do load calcs I always see that I can use much smaller, so I may start using 1/0 for the neutral.
> 
> I have never had an inspector say a thing about it, nor do I expect one to.




Yeah that's what that stuff is. We call it triplex or sweet briar. Probably wired a couple hundred resi services with that stuff back in my younger days


Sent from my iPhone using Tapatalk


----------



## backstay (Feb 3, 2011)

WronGun said:


> It's for service , my supplier has it In stock 4/0-4/0-4/0 , I'm going with that. I don't know why but I see an inspector busting my balls someday for the smaller neutral... covering my ass
> 
> 
> Sent from my iPhone using Tapatalk


4/0-4/0-2/0 is code for a dwelling at 200 amp service. 4/0 is not code for non dwelling 200 amp. Some situations(RV park) require a full size neutral.


----------



## Cow (Jan 16, 2008)

There is no reason to use a fullsize neutral for a single phase 240/120v dwelling service. 

Try reading article 220 and verify it for yourself.

You are going to waste far more time and money guessing at this stuff you don't know about, then if you take a few minutes, look it up in the NEC and educate yourself.


----------



## telsa (May 22, 2015)

A full size neutral is a gotcha moment if you're running 208Y120 -- but just two legs -- to an apartment or condo.

There are so MANY 240 loads in the typical residence that a 240/120 system just doesn't load the neutral all the way.

This grace is not permitted in commercial, industrial,... really anything beyond residential dwellings receiving 240/120.

%%%

Don't take this too far. A massive MCC distribution board feeder may well need a pitifully tiny neutral as 95% of its load are 3-phase motors. [ It has a trivial number of lighting and control circuits.] Its bonding conductor -- parallel runs -- may prove very hefty, indeed.


----------



## HackWork (Oct 2, 2009)

Around here we don't have many 240v loads since everything uses natural gas. Usually only AC units are 240v.

But even without any 240v loads, in order for you to need a full size neutral, you would have to be pulling 180+ Amps on one leg and zero current on the other.


----------



## sbrn33 (Mar 15, 2007)

Going_Commando said:


> Load calc it. I bet you are nowhere near 200A, so the nuetral is fine. In the NEC you can go 2 sizes down on the nuetral if your load calc allows, and I assume the CEC is the same.


Code section please....


----------



## B-Nabs (Jun 4, 2014)

I don't do residential, so someone please correct me if I'm wrong, but I have not observed many houses with a downsized neutral in these parts.


----------



## telsa (May 22, 2015)

B-Nabs said:


> I don't do residential, so someone please correct me if I'm wrong, but I have not observed many houses with a downsized neutral in these parts.


My Poco insists on pulling all service laterals -- and these are ALL for 200A Services. 

You can get 320A Services, but only upon request. And that's IT.

In every case they pull reduced neutrals. It's right in their Green Book.

NEVER does my Poco pull a full sized neutral to a residence receiving 240/120 power.

BTW, they demand a 3" Schedule 40 PVC raceway -- with a 3" GRC factory elbow coming up through the footer up to the All-in-One. 

(Their chit must fly in the hole.)

[ Which is all you see for miles and miles around. It's the weather, and it's the demand of the local political authorities. Overhead (residential & commercial) power is flatly banned. ]

The only thing run over head is ancient work and the Poco's own long distance transmission lines.


----------



## HackWork (Oct 2, 2009)

B-Nabs said:


> I don't do residential, so someone please correct me if I'm wrong, but I have not observed many houses with a downsized neutral in these parts.


That's because people are stupid and hate profit. The same reason why they install copper service entrance conductors.


----------



## ponyboy (Nov 18, 2012)

HackWork said:


> That's because people are stupid and hate profit. The same reason why they install copper service entrance conductors.




Copper is a far better conductor choice. Aluminum wiring is proven unsafe and prone to combustion, it's probably killed people too. I thought we were done with this aluminum wire fantasy 


Sent from my iPhone using Tapatalk


----------



## HackWork (Oct 2, 2009)

Biscuits said:


> Copper is a far better conductor choice. Aluminum wiring is proven unsafe and prone to combustion, it's probably killed people too. I thought we were done with this aluminum wire fantasy
> 
> 
> Sent from my iPhone using Tapatalk


Aluminum wiring hurt my feelings once.


----------



## jtopham26 (Apr 8, 2015)

Going_Commando said:


> Load calc it. I bet you are nowhere near 200A, so the nuetral is fine. In the NEC you can go 2 sizes down on the nuetral if your load calc allows, and I assume the CEC is the same.


Where is the code section for that? The utility can debate the neutral on their feeders and with PE oversight you can in the NEC jurisdiction but where do you see 2 sizes mentioned 

Sent from my SM-N920V using Tapatalk


----------



## HackWork (Oct 2, 2009)

jtopham26 said:


> Where is the code section for that? The utility can debate the neutral on their feeders *and with PE oversight you can in the NEC jurisdiction* but where do you see 2 sizes mentioned
> 
> Sent from my SM-N920V using Tapatalk


Where do you see "_with PE oversight you can in the NEC jurisdiction_" in the NEC?


----------



## sbrn33 (Mar 15, 2007)

WronGun said:


> Neutral is smaller
> 
> 
> Sent from my iPhone using Tapatalk


That is URD to me Triplex is overhead. 
But now that I look on my suppliers website they call it UD triplex.


----------



## Big John (May 23, 2010)

I ain't a resi. guy but my understanding is that you can size the neutral the same way you do the equipment ground just as long as your load calcs. show it has sufficient ampacity.


----------



## MechanicalDVR (Dec 29, 2007)

I've heard from many guys you can downsize the neutral but don't believe I' have ever seen it done in actuality. How much could you possibly save on one service?


----------



## HackWork (Oct 2, 2009)

MechanicalDVR said:


> I've heard from many guys you can downsize the neutral but don't believe I' have ever seen it done in actuality.


 You have seen it done in every instance that you've seen an SE cable service riser, they are always 4/0-4/0-2/0 for 200A and 2-2-4 for 100A.


> How much could you possibly save on one service?


Most likely enough to buy lunch.

I'm not sure how much it saves, but even if it's $1 it's still worth it. I always install 2/0 neutral with 4/0 hots, just like the SE cable configuration.

Not only is it less struggling pushing it thru the pipe, it's also 100% confirmation on which cable is the neutral since we often tend to forget to tape it first, and it saves us from having to ring it out when one end is 20+ feet in the air.

I don't see any negative. Just free lunch :thumbsup:


----------



## HackWork (Oct 2, 2009)

I was wrong, you actually can't buy lunch. It's like 14 cents a foot cheaper, less than $4 savings for a typical service change.

But the other benefits still exist so I will keep using it.


----------



## splatz (May 23, 2015)

HackWork said:


> I was wrong, you actually can't buy lunch. It's like 14 cents a foot cheaper, less than $4 savings for a typical service change.
> 
> But the other benefits still exist so I will keep using it.


Two hot dogs and a big soda < $4 at the gas stations here  

The sure identificaiton of the neutral, during install and in the future, and the easier pipe and LB stuffing are both good points.


----------



## frenchelectrican (Mar 15, 2007)

MechanicalDVR said:


> I've heard from many guys you can downsize the neutral but don't believe I' have ever seen it done in actuality. How much could you possibly save on one service?


I have done that few time before that with only 120/240 volts single phase services. ( 120/208 volt single phase service .,, full neutral conductor )

It is common if you know the supply house send ya those service entrance conductors like triplex with RN ( Reduced Neutral ) 

The cost between the full one and RN verison is that ya get a good lunch for sure. I am guessing about 1 to 5 bucks maybe more depending on the run.

The more you do use the RN the more you can able save it.

Ya the code did allow that for pretty long time


----------



## Cow (Jan 16, 2008)

MechanicalDVR said:


> I've heard from many guys you can downsize the neutral but don't believe I' have ever seen it done in actuality. How much could you possibly save on one service?


I don't do new residential, mostly ag, but I downsize to the bare minimum more often than not.

I just did a 200A 480v ag service for a 60HP well pump and some other miscellaneous load. 3/0 CU phases with a #3 neutral. 

The relevant codes:

220.61 tells you to calculate your neutral load

250.24(C)1 then tells you that it can never be smaller than Table 250.102(C)1.

So for services with strictly line-line loads and/or very little line-neutral loads, there are some pretty steep reductions allowed per the table.


----------



## papaotis (Jun 8, 2013)

what does yor local poco use on overhead? here its #4 AL. underground its AL. if the poco can use smaller AL wire than we can use in copper, what does that tell you?


----------



## HackWork (Oct 2, 2009)

papaotis said:


> what does yor local poco use on overhead? here its #4 AL. underground its AL. if the poco can use smaller AL wire than we can use in copper, what does that tell you?


That they don't care if their wire heats up as it free-airs or goes underground like we have to worry about in the wall of a house.


----------



## papaotis (Jun 8, 2013)

good point, hack. i wasnt thinking about the free air thing. but do you think its really needed to be sized bigger in the mast and betweenn the meter and panel? mostly outside. and here it has to be in 2" rigid even for a 100a


----------



## HackWork (Oct 2, 2009)

papaotis said:


> good point, hack. i wasnt thinking about the free air thing. but do you think its really needed to be sized bigger in the mast and betweenn the meter and panel? mostly outside.


You know I have no problem ignoring code when it's stupid. But in this instance it seems reasonable, especially between the meter and panel since that's inside of the house. The rest of the riser is outside, but I guess since it's against the house it's reasonable to want to keep it from getting too hot. 

The way I understand it is that we are not sizing it bigger than the PoCo. We are sizing it to the necessary size to keep the cable from heating too much and the insulation from failing. It's the Poco who is being cheap and undersizing it because they play by their own rules. 


> and here it has to be in 2" rigid even for a 100a


That sounds crappy. Here we can use anything, SE cable, PVC, EMT, rigid. 100A is in 1-1/4" pipe unless it's a mast popping out of the roof.


----------



## oliquir (Jan 13, 2011)

Biscuits said:


> Copper is a far better conductor choice. Aluminum wiring is proven unsafe and prone to combustion, it's probably killed people too. I thought we were done with this aluminum wire fantasy
> 
> 
> Sent from my iPhone using Tapatalk


hmm i hope you are kidding, alu was dangerous back in the 70s for small gages , it is in use everywhere now for services, copper is 3-5 times more expensive


----------



## ponyboy (Nov 18, 2012)

oliquir said:


> hmm i hope you are kidding, alu was dangerous back in the 70s for small gages , it is in use everywhere now for services, copper is 3-5 times more expensive




Not kidding at all. Copper may be 3-5 more expensives but it's also 5-8 times more safety. 


Sent from my iPhone using Tapatalk


----------



## papaotis (Jun 8, 2013)

yeah, hack, it is the part going through the roof that has to be 2", but it ALL has tobe in rigid


----------



## sbrn33 (Mar 15, 2007)

Biscuits said:


> Not kidding at all. Copper may be 3-5 more expensives but it's also 5-8 times more safety.
> 
> 
> Sent from my iPhone using Tapatalk


Are you even an electrician?


----------



## ponyboy (Nov 18, 2012)

sbrn33 said:


> Are you even an electrician?




I am an electrician yes but I identify as a Russian attack helicopter. 


Sent from my iPhone using Tapatalk


----------



## HackWork (Oct 2, 2009)

Biscuits said:


> I am an electrician yes but I identify as a Russian attack helicopter.


Damn Russian. I'm American:


HackWork said:


> I sexually identify as an attack helicopter.


----------



## papaotis (Jun 8, 2013)

HackWork said:


> Damn Russian. I'm American:


does that mean you hover in and blow up things/:icon_wink:


----------



## xavier27 (May 22, 2016)

I would say you are good with that triplex or sweet briar for a service. I use it all the time with no issues from inspectors.


----------

