Help needed for a wire splice - ideas please

[glandpuck]

Hello. I have a situation for I am not certain of the optimal repair method. I have a 90 foot length of buried 2 inch grey PVC conduit that ends with 45 degree elbows to the surface. Through this conduit runs a 8 AWG green ground wire and then 3 sets of PV wires. Each of the 3 sets is as follows: PV1+, PV1-, PV2+, PV2-, PV3+, PV3 -. All of the PV wires are 4 AWG. So the 2 inch conduit has six 4 AWG wires and one 8 AWG wire. The original electrical wiring done 8 years ago used split bolt splices which over time resulted in corrosion. I was able to use NSI Polaris waterproof splices and make new splices which worked fine for PV1+, PV1-, PV2+, PV2-, PV3+, BUT PV3- EXPERIENCED TOO MUCH CORROSION AND ALSO THE WIRE END LEFT STICKING OUT FROM THE CONDUIT WAS VERY SHORT TO START. THE END RESULT IS THAT PV3- WIRE IS BARELY STICKING OUT OF THE CONDUIT SO I CANNOT ATTACH A SPLICE TO IT. AT THE OTHER END, 90 FEET AWAY, THE END STICKS OUT LIKE 6 INCHES.

I have excavated the conduit and exposed the PVC glue joint from the straight piece to the 90 degree elbow. the attached photos show circled the stump wire of the PV3-. So I need to somehow splice on additional wire to PV3- or try to pull a new wire through the conduit or something else. I was thinking cutting off the 90 degree elbow in the ground, installing a NEMA3R box and having all of the conduit wires run through that and splice on a piece, but that is a big job. The other idea is to cut off the 90 degree piece as well as about 10 inches of conduit. Then install a new 90 degree piece which would effectively make the wires 10 inches taller. then I just need to run in a ground box to the other ends.

Any ideas on how best to approach this would be great and much appreciated.

 

[Haze]

I would cut the conduit and install a box for all the wires to live in.

Is that a water line ran in the same trench as the DC power ?

 

[glandpuck]

Yes, that's a water line in the same trench. the electrical is 18 inches under ground to top of conduits. There are 2 electrical conduits, the 2 inch one carries the PV DC the 1 inch other carries a 120V AC. They are next to each other. So I cannot just cut the Dc conduit and insert a box because the 1 inch conduit lies next to it. My plan now is to cut back the 2 inch DC conduit upright and use an NSI waterproof splice on the shortened wire. Failing that, I may try to pull a new wire or cut back further.

Remember conduits are not waterproof, the insulation of the wire is waterproof. The waterline can be run just inches below the ground level. Its a 3/4 inch schedule 40 PVC line.

 

[glandpuck]

A repair has been completed. The exposed conduit was filled with mud and some stones and water. When wires, especially large 4 awg are in a conduit and there is a bend, the wires want to follow the larger radius, not the smaller radius of the bend. This put the wires against the back wall of the conduit. Your fingers can be inserted into the conduit in front of the wires.

Please see the photos. The solution was to purchase an NSI Polaris Edge submersible wire connector part number ISPB2/0-2B. This is an end to end vs side by side connector. I used a Bosch oscillating edge tool to cut a slit into the conduit about 5 inches below the top of the conduit. This allowed muddy water to leak out of the conduit. Next I cut down through the conduit 5 inches to meet by slit cut. The vertical cuts were about 1.5 inches apart. This resulted in a part of the conduit wall being removed. The wire in question was then pulled out of the conduit with a length of close to six inches. The slice connector was placed into position to make certain f the fit for length. With this confirmed, the corroded wire was cut off and new wire stripped and confirmed to be shiny copper. The Polaris wire connector was installed. Next, a piece of 4 AWG THHN THWN was cut to length to be installed as a jumper between the new Polaris wire connector and the older Polaris wire connector. This re-established the PV- connection.

Following this, the PV at the inverter and at the arrays was turned back on and proper connections confirmed.