By Hal_S
Swimming pool setup worked for decades with a 40 year old pool pump and a reused 1/2 hp 115v AOSmith motor that met the pump specs.
Pump finally rusted beyond being patchable. Impeller was worn down.
Swapped in a 20 year old pool pump with new impeller, with a reused 1/2 hp Marathon motor.
AOS is model S48H2N103, Marathon is an O213 model 56C34D2099
Motors are basically identical in all specs hp, hz, rpm, SF etc.
Minor difference is the Marathon is set to run at 240v (tag says 5.2amps / 3.6amps.)
Pool is about 40′ from the garage sub-panel, wiring is 14 gauge.
AOS basically ran 24/7 from mid May to mid September. Now, the AOSmith motor always ran warm, (amps on tag are 6.7/8.4) but the Marathon motor runs hot to the touch, trips the overheat protection after about 4 hours during a 90 degree day.
Used compressed air to blow out the dust and spiders; guess the next step is to disassemble the Marathon, clean off, reassemble and hope it runs cooler.
So, any suggestions on how why a motor runs hot and what to check?