2-2-2-4 Wire Question

[akcooper9]

Local shop is trying to sell me this for the detached garage.

http://images.tradeservice.com/gjPilrcyNvvpVtln/ATTACHMENTS/DIR100054/SOUWIRE00237_1-3.pdf

Is it the right stuff? I laid 2" conduit. From the house main panel, the conduit is on the outside of the house and on the shop side it comes up through the slab right into the panel.

All the different types of 2-2-2-4 has me

 

[Stuart in MN]

That's for use in above ground installations, and it sounds like you're using underground conduit.

 

[akcooper9]

it sounds like you're using underground conduit.

Correct it is under ground conduit.

 

[joe_padavano]

You need USE-2/RRH/RHW-2, which is commonly called mobile home feeder. Good for direct burial or underground conduit use. Home Depot and Lowes sell it in 2-2-2-4.

 

[theoldwizard1]

You need USE-2/RRH/RHW-2, which is commonly called mobile home feeder. Good for direct burial or underground conduit use. Home Depot and Lowes sell it in 2-2-2-4.

Mobile Home Feeder spec

Can be direct buried as mentioned, but must be in conduit above ground.

 

[The mean fish]

Local shop is trying to sell me this for the detached garage.

http://images.tradeservice.com/gjPilrcyNvvpVtln/ATTACHMENTS/DIR100054/SOUWIRE00237_1-3.pdf

Is it the right stuff? I laid 2" conduit. From the house main panel, the conduit is on the outside of the house and on the shop side it comes up through the slab right into the panel.

All the different types of 2-2-2-4 has me

That's exactly what I ran to my shop in 2" conduit, total pull was about 180'. I bought 450' of it from a guy on CL who build apartments complexes and this is what they ran to each smaller unit from a central point. I added some oxidation preventer when hooking up to the breakers on the ends and it's been great for 2 years now.

 

[Charles (in GA)]

EDIT: I guess I didn't read the PDF fully. While the wires are rated as thhn/thwn/xhhw-2, the entire cable assembly is only rated as SE and CANNOT be used below ground..... My bad, I know better, but was posting on the phone and didn't throughly look at the PDF.

So the OP needs to get the MHF that was talked about earlier............

Sorry..... I hate posting on the phone.

Charles

 

[joe_padavano]

Read the pdf that the op linked to. It is multi rated as thhn/thwn/xhhw-2 in addition to se. Quite ok for what the op wants to use it for.

You are correct, however the jacket will make it less flexible and more difficult to pull through the conduit than four separate conductors. Of course, 2-2-2-4 in 2" conduit probably won't be a big problem.

 

[Charles (in GA)]

You are correct, however the jacket will make it less flexible and more difficult to pull through the conduit than four separate conductors. Of course, 2-2-2-4 in 2" conduit probably won't be a big problem.

Please see my edit above............

Charles

 

[pattenp]

If you ran SE cable under ground in conduit then the odds are at some time the ground conductor may fail because it's not insulated (bare). SE having a bare ground conductor is why the cable is not approved for below ground use, even in conduit.

That's exactly what I ran to my shop in 2" conduit, total pull was about 180'. I bought 450' of it from a guy on CL who build apartments complexes and this is what they ran to each smaller unit from a central point. I added some oxidation preventer when hooking up to the breakers on the ends and it's been great for 2 years now.

*

 

[akcooper9]

Thanks for the help guys. Found a different local shop that was able to order in the correct MHF with a USE-2 rating. Hopefully Ill have power this weekend

 

[Norcal]

That's exactly what I ran to my shop in 2" conduit, total pull was about 180'. I bought 450' of it from a guy on CL who build apartments complexes and this is what they ran to each smaller unit from a central point. I added some oxidation preventer when hooking up to the breakers on the ends and it's been great for 2 years now.

The bare AL grounding conductor will turn to a toothpaste like substance underground.

 

[The mean fish]

If you ran SE cable under ground in conduit then the odds are at some time the ground conductor may fail because it's not insulated (bare). SE having a bare ground conductor is why the cable is not approved for below ground use, even in conduit.
*

The bare AL grounding conductor will turn to a toothpaste like substance underground.

Then I'll replace it if that ever happens, not a big deal at all.

 

[pattenp]

So.. just how do you plan on knowing that your equipment ground is starting to fail to even know when to change out the wire? Are you going to test it every year or so?

Then I'll replace it if that ever happens, not a big deal at all.

 

[The mean fish]

So.. just how do you plan on knowing that your equipment ground is starting to fail to even know when to change out the wire? Are you going to test it every year or so?

The sub panel in my shop is grounded via it's own pair of local copper grounding rods and the ground and neutral are not bonded in the sub panel so I'll likely never know if water ever did manage to get in the conduit.

I also also have an 80 gallon air compressor with a 240volt 5HP motor on top with the belt guard not installed.

I like living on the edge.

 

[teamextreme]

You'll likely never know unless you have a ground fault of some kind that doesn't clear because you don't have a low resistance path to ground because your ground wire has corroded and you or someone else gets electrocuted or your circuit overloads and causes a fire. No biggie. The ground rods do not replace a ground conductor back to your panel. They usually will not provide a low enough impedance path to ground to cause a circuit breaker to trip when it needs to.

 

[Mustang51js]

The ground rods are just for a place for the voltage to go when there's a short circuit and lightning strikes. Otherwise it would come out outlets and such. I have yet to see an underground pipe not get water in it after a while. Only thing you could do is test it once in a while

 

[walrus]

You'll likely never know unless you have a ground fault of some kind that doesn't clear because you don't have a low resistance path to ground because your ground wire has corroded and you or someone else gets electrocuted or your circuit overloads and causes a fire. No biggie. The ground rods do not replace a ground conductor back to your panel. They usually will not provide a low enough impedance path to ground to cause a circuit breaker to trip when it needs to.

This.


My dad direct buried a piece of SE 30 years ago out to his shop, its still there but its not being used at the moment. The whole place needs to be rewired, house, shop and all

 

[wyliesdiesels]

You'll likely never know unless you have a ground fault of some kind that doesn't clear because you don't have a low resistance path to ground because your ground wire has corroded and you or someone else gets electrocuted or your circuit overloads and causes a fire. No biggie. The ground rods do not replace a ground conductor back to your panel. They usually will not provide a low enough impedance path to ground to cause a circuit breaker to trip when it needs to.

Exactly! Grounding electrodes and equipment grounds provide 2 different protections!

The ground rods are just for a place for the voltage to go when there's a short circuit and lightning strikes. Otherwise it would come out outlets and such. I have yet to see an underground pipe not get water in it after a while. Only thing you could do is test it once in a while

Incorrect. Grounding electrodes are only for lightning strikes. Electricity doesnt go to the ground rods when theres a short circuit!

 

[Mustang51js]

Incorrect. Grounding electrodes are only for lightning strikes. Electricity doesnt go to the ground rods when theres a short circuit![/QUOTE]

Well where does it go when there's a short,if it goes to nuetral then more than likely goes to ground also

 

[C96]

Oh my…. The possibility of a deteriorating ground and no belt guard on your compressor, dude you need Life Alert!

 

[The mean fish]

Oh my…. The possibility of a deteriorating ground and no belt guard on your compressor, dude you need Life Alert!

I've used an angle grinder plugged into that potentially fatal, groundless sub- panel with a Harbor Freight cutting disk on it... wearing sandals. I'm basically a dead man walking.

 

[teamextreme]

Incorrect. Grounding electrodes are only for lightning strikes. Electricity doesnt go to the ground rods when theres a short circuit!

Well where does it go when there's a short,if it goes to nuetral then more than likely goes to ground also

A line to neutral fault will cause a excessively high fault current to travel thru the breaker and neutral conductor causing the breaker to trip on overcurrent, like it's suppose to.

A line to ground fault, will do the same only the current will travel over the low impedance equipment grounding conductor, also causing the breaker to trip. The key being a low impedance path back to the source (ultimately the transformer) to allow a high current to flow. If the ground wire is missing or compromised to a detached building as in this discussion, the ground fault current must travel to the ground rod and then through the earth back to the source. How many feet of dirt would this be, and more importantly, how big a resistor is this? The resulting ground fault current will not be sufficient to trip the breaker quickly. This would also cause voltage to be present on the ground wire in the garage until the breaker tripped (if it ever did).

So no, a ground rod in a detached building does not provide an effective equipment grounding system alone. It is only there to provide a path to ground for a lightning strike.

 

[wyliesdiesels]

A line to neutral fault will cause a excessively high fault current to travel thru the breaker and neutral conductor causing the breaker to trip on overcurrent, like it's suppose to.

A line to ground fault, will do the same only the current will travel over the low impedance equipment grounding conductor, also causing the breaker to trip. The key being a low impedance path back to the source (ultimately the transformer) to allow a high current to flow. If the ground wire is missing or compromised to a detached building as in this discussion, the ground fault current must travel to the ground rod and then through the earth back to the source. How many feet of dirt would this be, and more importantly, how big a resistor is this? The resulting ground fault current will not be sufficient to trip the breaker quickly. This would also cause voltage to be present on the ground wire in the garage until the breaker tripped (if it ever did).

So no, a ground rod in a detached building does not provide an effective equipment grounding system alone. It is only there to provide a path to ground for a lightning strike.

Thx for expanding on my comment. That is more detail than i had time to type!!

 

[Todd.Brock]

The reason I love this forum in is the seArch function !!! My neighbor is running a 100a sunpanel to his basement. Going outside , 2ft under ground by the house, then back in. If I read correctly, 2/2/2/4 SER is not rated for underground even in conduit . But it is rated for outdoor/ wet location. Does that mean it can be run above ground outside strung up from a pole, just not buried ?

2/2/2/4 **** wire is URD listed so it can be buried but is not approved inside structures.

2/2/2/4 MHF is cool to run outside in conduit above ground , direct buried, AND used in a structure.

The run is 80 ft and will be limited to 90 amps.

Thanks!

 

[theoldwizard1]

If I read correctly, 2/2/2/4 SER is not rated for underground even in conduit.

Correct !

2/2/2/4 MHF is cool to run outside in conduit above ground , direct buried, AND used in a structure.

It must be in conduit inside of a structure also.

 

[pattenp]

SER can be used outside above ground but needs to be protected if subject to possible damage. It can not be strung from a pole, it needs to be supported/secured just as NM when installed. SER is not an aerial cable.

.... Does that mean it can be run above ground outside strung up from a pole, just not buried ?

 

[Todd.Brock]

Thanks for the info! How would you protect SER above ground? Conduit? Could you just run SER about ground , secure it to the house and then run it to the back side of the house where it goes back through the siding into the bsmt?


The trench is already dug so it will probably go below ground either way. Does SER need to be in conduit in the house? I ran SER in my house to the bsmt, through the attic and into bsmt. 3 electricians didn't say anything anbout conduit !

 

[pattenp]

Todd, you can run the SER outside above ground along the wall but it should be in conduit for protection. Where SER is installed inside it does not need to be in conduit as long as it's not subject to being damaged.

 

[Todd.Brock]

Pattenp and everyone else. thank you for the information. Just to be clear , MHF does need to be in conduit inside, but SER does not?

The sub panel is only a couple feet from the entrance so conduit shouldn't be too big a deal, just awkward. I think he bought 1.5" conduit

 

[pattenp]

Correct. Because SER has an outer sheathing it's treated just as NM for installation requirements. MHF is free conductors without an outer sheathing so it needs to be in conduit when above ground and inside. The 1.5" conduit is okay, but don't go any smaller.

Pattenp and everyone else. thank you for the information. Just to be clear , MHF does need to be in conduit inside, but SER does not?

The sub panel is only a couple feet from the entrance so conduit shouldn't be too big a deal, just awkward. I think he bought 1.5" conduit

 

[Todd.Brock]

Again, many thanks!

 

[Todd.Brock]

So the neighbor bought 2 conductor SEU. The guy at Home Depot said it is direct burial , and to twist the ground strands together and use it for a neutral. Then bury a grounding rod. I tried to convince the guy but in the end HD outranked me...

 

[Aceman]

So the neighbor bought 2 conductor SEU. The guy at Home Depot said it is direct burial , and to twist the ground strands together and use it for a neutral. Then bury a grounding rod. I tried to convince the guy but in the end HD outranked me...

Your neighbor is an idiot.

The neutral in that SEU is going to corrode and turn into a white chalk. When it does your neighbor is going to experience classic corroded neutral problems. Under/overvoltages and current seeking any path it can back to the main panel.

One service call I had for a corroded neutral a few years ago, the path current was taking was through a chainlink fence. Anytime the gate was closed it would arc when it made contact with the latch. The homeowner and her dog would get shocked when they passed through the opening. Fortunately, nobody got killed.

He needs four wires and not SEU!

 

[pattenp]

Ditto to what Aceman said. The Home Depot guy must think that the "U" in SEU stands for underground. Actually 2 conductor SEU has no ground, the concentric wire is the neutral.

So the neighbor bought 2 conductor SEU. The guy at Home Depot said it is direct burial , and to twist the ground strands together and use it for a neutral. Then bury a grounding rod. I tried to convince the guy but in the end HD outranked me...

 

[Todd.Brock]

You can only do so much! I swear the concentric wire looks smaller. It doesn't look like 2-2-2

 

[Flexia]

I thought MHF could be used indoor locations with out conduit? I plan on running mine inside to my main panel in the house and I think conduit its going to make it a big PITA once it enters the house above grade.

 

[pattenp]

Nope. MHF when installed inside needs to be in conduit. If you can't get conduit to the panel then switch to SER using a junction box where the MHF enters the structure. You can place the jbox either on the outside or just inside the structure.

I thought MHF could be used indoor locations with out conduit? I plan on running mine inside to my main panel in the house and I think conduit its going to make it a big PITA once it enters the house above grade.

 

[Flexia]

Nope. MHF when installed inside needs to be in conduit. If you can't get conduit to the panel then switch to SER using a junction box where the MHF enters the structure. You can place the jbox either on the outside or just inside the structure.

So that means SER can you used in conduit above ground outdoors?

 

[pattenp]

SER can be used above ground outside either in conduit or not in conduit. Conduit is only required if the SER is installed in a location that may subject it to damage.

So that means SER can you used in conduit above ground outdoors?