I have wired two hot tubs before. The first one was a Master Spa which required 240V 50 amp service. I used a feeder cable 6/3 with an uninsulated ground even though the ground was encased in the grey flat romex (also ran it through PVC 18” deep) and used GFI breakers. It worked great for over 12 years before we sold the house. Recently I wired a smaller “outside” hot tub and this time I used 6/3 romex and went from the house to the tub of about 8 feet. I ran this wire through the flex gray conduit and had no problems.
Now I have a bigger project with the swim spa, I need to run 2 separate 50 amp 240V circuits about 60 feet underground. The manufacturer required 6 gauge wire with 4 insulated wires, hence it needs to be a 6/4. They do NOT specify which wire to use only that it needs to be 6/4. The reason for the 6/4 is because they want all wires insulated to include the green ground wire. Here lies the problem. I can only find this wire in a SOOW wire and although the many claims of extreme durability, I don't feel this is the right wire. I do not like that this wire is multi stranded. I’m not opposed to say maybe an 8 strand wire to make up a 6 gauge but do NOT like using a stranded wire with about 101/26 to make up the 6 gauge. If I am not mistaken the spec 101/26 means that there are 101 strands at 26 gauge each. I question the durability of this wire due such high voltage and amperage. Could there be a drop on amperage with so many strands when using 101/26 verses say a 8/16 or so? Wouldn’t it better to use a thicker stranded or solid copper wire? Which ever wire I use I am putting it in the grey PVC underground so does it really need to be a 6/4 insulated wire?
Now I have a bigger project with the swim spa, I need to run 2 separate 50 amp 240V circuits about 60 feet underground. The manufacturer required 6 gauge wire with 4 insulated wires, hence it needs to be a 6/4. They do NOT specify which wire to use only that it needs to be 6/4. The reason for the 6/4 is because they want all wires insulated to include the green ground wire. Here lies the problem. I can only find this wire in a SOOW wire and although the many claims of extreme durability, I don't feel this is the right wire. I do not like that this wire is multi stranded. I’m not opposed to say maybe an 8 strand wire to make up a 6 gauge but do NOT like using a stranded wire with about 101/26 to make up the 6 gauge. If I am not mistaken the spec 101/26 means that there are 101 strands at 26 gauge each. I question the durability of this wire due such high voltage and amperage. Could there be a drop on amperage with so many strands when using 101/26 verses say a 8/16 or so? Wouldn’t it better to use a thicker stranded or solid copper wire? Which ever wire I use I am putting it in the grey PVC underground so does it really need to be a 6/4 insulated wire?
