I am a relatively new spa owner, and I could use some advice on how to troubleshoot or resolve a problem, or if I am dealing with normal behavior: When my spa pump turns on, it initially draws so much current that the voltage in the entire house fluctuates briefly (i.e. lights dim or brighten, depending on what phase they are on), until the pump stabilizes at the normal current. Here are more details:
Supply voltage: 110V, dedicated 20A breaker
Pump: 2-speed Cal Spas PL-353 with GE Motor 5KC38RN3818X, 110V, 12A (high speed), 4A (low speed)
Pump startup current surge: 43A peak, less than 1 sec, happens for both high & low speed
While the power surge is noticeable throughout the house from light dimming/brightening and a buzz at the breaker box, it doesn't last long enough to either trip the breaker or usually blow the 20A slow-blow fuse (although the fuse did blow a single time, but that hasn't happened again after replacing). I'm afraid the power fluctuation will damage other equipment in the house, so I've turned the spa off until the problem is resolved.
I've opened up the pump and found a 161-193 uF capacitor. My multimeter only goes up to 100 uF, so I can't tell if the capacitance value is correct, but it doesn't appear to be leaking current, and it does have charging behavior according to resistance measurements. I removed the capacitor from the pump and turned it on to see if the behavior was consistent, but the motor would not turn and drew 43A while making a whining sound. Also, I was able to turn the pump shaft with a screwdriver, and there was a very small amount of high-pitch noise during rotation, which may be normal from the motor windings.
I've had this spa for a few months now, and I don't recall having this problem initially, and it seems to be getting worse. However, maybe I was blinded by the enjoyment of the spa and didn't notice the problem until now. Is a 43A startup current surge on a 12/4A pump normal? I hope not, and so what are the next steps to troubleshoot and resolve the issue? Replace the capacitor? Use a larger capacitor? Add a local battery? Replace the motor? Rebuild the pump with new impeller? Replace the entire pump? Any help would be greatly appreciated!