Pool tripping GFCI breaker

[Chris75]

I just found out that the previous electricains did work on this circuit left the system open for three weeks and water leaked into the conduit. It's old wire, not THHN or THWN. I told the home owner to contact them and they can pull new wire. The pump is a 1 1/2 HP running amperage is 18.6 and is really pushing a 20amp circuit. That's what's been there for 8 years though. I told the homeowner to have the other electricians pull a 240 volt circuit for the pool pump and convert it to 240V. Then it'll only draw about 8.3 amps.

Exactly my point on my comment of a 1.5 HP pump at 120v, it would be a code violation anyways, since they are on for more than 3 hours.