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Sorry guys, but the answer is ...If the junction box has any way of getting moisture inside, then you need to pull new cables unless you can perform a water proof splice. Soldering and heat shrink are not the answer. The split bolt will only work if it is waterproofed properly. Either pull new wires or call a good electrician who can guarantee the work.Steve
The NEC specifies that there should be no splices in the ground conductor from the spa to the shutoff, and then from there to the main panel. Many inspectors will let it go, however.The other wires may be spliced - I would not recommend splicing the ground conductor. 8-)