Crossing underground propane and electrical conduit

[jives]

Hi all;
Got a question for you electricians and HVAC folks. While we've got the gravel driveway all messed up with our garage build, we want to go ahead and dig a trench for the electrical service to come off the house. We will be putting in PVC conduit and then will have it inspected.

The concern is that the conduit will cross the underground copper propane line that is about 24" deep. Are there restrictions on this? Depth? Separation materials?

BTW, the electrical inspector was pleasant, but he was resistant to giving advice other than send me to the NY Residential Code book. I could not find anything in there, but that does not mean it doesn't exist.

One final thing. . . This will be a "typical" electrical install with 4-conductor wiring coming from the house 200A panel to the garage 100A panel. Will a 1.5" conduit be big enough. Or will I need a 2" conduit?

 

[sberry]

How far and how many turns? 1 1/2 will do it but if its simple 2 inch isn't much more in cost and is way easier. I wouldn't want the conduit touching the LP but it can cross with no worry.

 

[jives]

How far and how many turns? 1 1/2 will do it but if its simple 2 inch isn't much more in cost and is way easier. I wouldn't want the conduit touching the LP but it can cross with no worry.

Length is about 70', two 90 deg bends underground plus the Type LB fitting as the cable enters the house.

 

[alfredeneuman]

The best way to do this is to contact the Power Company and ask them what they want as far as conduit size.

Many times they require a larger conduit than required by the NEC.
POCOs aren't subject to the NEC rules.

 

[Mustang51js]

The best way to do this is to contact the Power Company and ask them what they want as far as conduit size.

Many times they require a larger conduit than required by the NEC.
POCOs aren't subject to the NEC rules.

Not sure if it would count for poco since it's not the main service ,but I know around me for the service it's next size up than what you would normally use for above ground

 

[CNGsaves]

You don't want to be "crossing" the propane line that is at 24" depth. Instead, you should hand dig near the propane line and have electric go UNDER the propane line much deeper like 36" deep or whatever your AHJ says feed for subpanel should be to garage.

+1 for 2" Sch 40 conduit for the whole electrical run. Put your electrical run in conduit the entire way. Once above ground, the conduit needs to be Sch 80.

Sparkies will chime in to what wire you should use based on length from main panel to sub. Really need 100A in garage?? Often 90A is plenty and can use MHF Al 2-2-2-4 if run isn't too long.

 

[wyliesdiesels]

Hi all;
Got a question for you electricians and HVAC folks. While we've got the gravel driveway all messed up with our garage build, we want to go ahead and dig a trench for the electrical service to come off the house. We will be putting in PVC conduit and then will have it inspected.

The concern is that the conduit will cross the underground copper propane line that is about 24" deep. Are there restrictions on this? Depth? Separation materials?

BTW, the electrical inspector was pleasant, but he was resistant to giving advice other than send me to the NY Residential Code book. I could not find anything in there, but that does not mean it doesn't exist.

One final thing. . . This will be a "typical" electrical install with 4-conductor wiring coming from the house 200A panel to the garage 100A panel. Will a 1.5" conduit be big enough. Or will I need a 2" conduit?

I would use 2". Will be easier.

What equipment will u have? Any high draw stuff like AC, comp, heater, h20 heater, etc?

As CNG said, i wouldnt cross it right at 24". I would go deeper and DEFINITELY hand dig near the propane line.

The best way to do this is to contact the Power Company and ask them what they want as far as conduit size.

Many times they require a larger conduit than required by the NEC.
POCOs aren't subject to the NEC rules.

This isnt a main service. So PoCo rules dont apply...helps to read

 

[alfredeneuman]

:tard:

Oops

 

[sberry]

Alfred makes a point though, they come down the pole 2 but when we supply the pipe they want 3.

 

[jives]

You don't want to be "crossing" the propane line that is at 24" depth. Instead, you should hand dig near the propane line and have electric go UNDER the propane line much deeper like 36" deep or whatever your AHJ says feed for subpanel should be to garage.

+1 for 2" Sch 40 conduit for the whole electrical run. Put your electrical run in conduit the entire way. Once above ground, the conduit needs to be Sch 80.

Sparkies will chime in to what wire you should use based on length from main panel to sub. Really need 100A in garage?? Often 90A is plenty and can use MHF Al 2-2-2-4 if run isn't too long.

So, what you're saying is that I'll need slope the conduit from 18" underground by garage to about 36" underground near the house where the LP line is. That is, what you're saying is that this is going to be a PITA to dig. . .

 

[Bondo]

Ayuh,.... I'd just run it at 18", that's still 18" Above the gas line,.....

 

[jives]

Ayuh,.... I'd just run it at 18", that's still 18" Above the gas line,.....

Well, at least 6" above the gas line. That is what I am also hoping, assuming that the gas is 24". But, we are getting close to the house here where the lines need to cross, and I'm not 100% sure exactly how deep the gas line is. I reckon this will be the first place I dig.

 

[6768rogues]

I have property in the Finger Lakes region and I am putting in natural gas to a building. The gas utility said I could run other utilities in the same trench, but they have to be separated by at least 12" and have to be shelved (not directly on top of or below any other utility). You are not doing that, so I don't know if the 12" rule would apply to crossing another utility.
The Department of State regulates the code in NY and there is both a fuel gas code and an electrical code. The fuel gas code is available online because it is a NY publication. The electrical code is referenced to a NFPA document, and they are typically not free. I would look in the fuel gas code, since it is online for free.

 

[sberry]

Why did you assume the gas line is at 24? Despite some concern here this is a common job, not everyone makes 4 calls and talks to 8 experts every time they do it. I guess I just assume electric is at 24 but dig along and miss the other pipe, it really aint a lot more complicated than that.
18 would be in a minimum in residential I spose and utilities (POCO) may want 24?
But it doesn't get any better than wire in pipe in congested area.

 

[CNGsaves]

So, what you're saying is that I'll need slope the conduit from 18" underground by garage to about 36" underground near the house where the LP line is. That is, what you're saying is that this is going to be a PITA to dig. . .

No, I was saying 36" deep the WHOLE LENGTH for electrical bury . . . or DEEPER if your AHJ calls for deeper !! 18" deep is what cable subcontractor might put RG6 for CableCo (low voltage). 12" is what sprinkler water lines might be. Why settle for mediocre 18" ??? I sure would not want my electrical only buried 18" deep. You really want chance of digging into your electrical wire any time a bush is planted in yard??

Also, your supplied power from house won't come from meter, but from breaker in main panel with new conduit out and down exterior of house. Garage will get it's subpanel power also on exterior of building with Sch 80 conduit above ground, and Sch 40 below ground.

Do it once, do it right !!

 

[alfredeneuman]

Digging the trench is the least "glamorous" aspect of doing electrical work, but it has to be done nonetheless. Jives seems especially reluctant.

Hire some laborers to do the digging if you need to but as CNGsaves said above, Do it once, do it right !!

 

[zmaxmotorsports]

Bury it 30" deep from one end to the other,Put an expansion joint on each end about a foot above where it comes out of ground to protect from frost heaving.
Definitely use 2" pvc for anything under ground.

 

[CNGsaves]

^ ^ Great point on the expansion / slip joint. I forgot to mention that.

My neighbor was having problem of meter pulling out/pulling down his siding . . . because the PoCo did not put any slip joint in the buried feed of his electrical. Since siding was the cheap masonite . . . BEHIND the meter . . . this was real mess as very difficult to repair/replace the siding behind the meter. Frost heave can push up, but also SETTLING can pull Down on your conduit.

Get just one chance to do it right, and Zmax is spot on with NEEDing the slip joint.