Underground wire and conduit

[Banjo Bud]

I know codes are different everywhere but speaking of the majority of codes, if I run my wire underground inside of conduit, do I still need to use underground wire? Or can I use regular wire?

 

[Drick]

Conduit isn't rated for non metallic cable (Doesn't matter if its weatherproof or not). Instead use stranded cable. Get three spools of THHN, one green, one back, and either white for 120V or red for 240V and pull those through the conduit.

 

[Sponsor]

 

[Fitter30]

+1

 

[Boycedrilling]

I use submersible pump cable inside the well. From there to the control box, it's individual strands of THHN, inside of conduit. The splice from the sub wire to THHN is made inside of The well head. This is considered a "wet location" according to the National Electrical Code (NEC). This means that regular wire nuts are not permitted. It has to be water resistant wire nuts (the jelly filled ones). Same if you use Polaris connectors. Or you can use a waterproof splice kit. My electrical inspector checks this and will cite me for regular wirenuts. Also if the casing is metalic, it has to be grounded. From the start box back to the breaker panel is also run in conduit. Unless it's inside a wall in residential construction. Then it can be romex.

 

[Boycedrilling]

Existing breaker panel in shop. Added breaker for pump. Orange romex is inside wall to box, then out to metallic flex into VFD control box. Pvc Conduit then goes thru the wall to exterior of building. Then under ground 30-40 ft to well. Thhn wire still have to be pulled into the pvc conduit. This is for a 503 grow operation (pot farm)

 

[Boycedrilling]

Here’s a pump house for a new residence

 

[Boycedrilling]

pump house for a church. Underground power from 800 amp service in chapel to subpanel in pump house. All surface mount conduit in pump house. Chlorine injection system and contact tank. Chlorine is only injected during regen of treatment system. This is to eliminate potential of iron bacteria fouling of water treatment media. Water treatment for removal of iron and manganese

 

[Boycedrilling]

Outdoor installation of equipment for drip irrigation with cycle stop valve

 

[Banjo Bud]

Wow Mr Boyce, that’s a ton of information. I appreciate your time in putting that together. But actually, my application is much simpler and doesn’t even have to do with a well. I want to install a 4x4 post in my wife’s flower garden with a receptacle on it. I’ll run the wire from my garage about 100’.

 

[Boycedrilling]

Out here, we put all underground wiring in conduit, even if it’s rated for direct burial. Why? Rodent protection and ease of replacement

 

[Banjo Bud]

Never thought about rodents. Good idea. Thanks.

 

[Boycedrilling]

Rodents seem to think that the insulation on wires is quite tasty.