Hi Folks,
I've dropped in a retrofit Century variable speed motor (EVO 2.25hp) to replace a 13yr+ old single speed motor on my Sta-Rite pump. The kit included a new impeller, diffuser, seal. The problem I've been seeing is the pump won't start by itself unless an Allen key is first inserted in the back of the motor and the shaft rotated slightly. (The shaft itself does rotate freely btw). This has happened to the "first" new pump as well as its warranty replacement...
I rechecked the mains connections and took some current measurements with a clamp on AC ammeter: Clean 120v L/G, 240V L1/L2, doesn't droop at all on start. When it attempts to start, the unit draws 270mA for 5s or so, then (a relay or something) clicks softly and the current drops to 250mA. This cycle continues for some minutes before it times out and the LED control button flashes 4 times to indicate a seized shaft. If I power off, rotate the shaft slightly, then power on, the unit will soft start up to full prime speed, with the current draw eventually reaching 6.8A. It'll run all day once started, then be stuck the next morning.
Seems as though the unit's "soft start" is so low torque that it can't overcome the token startup friction between the impeller and diffuser (which came matched in this kit btw). Does anyone have background on whether such small startup current measurements are typical or a sign of a defective unit? Anybody experience something similar?
Thanks in advance for any advice here!
I've dropped in a retrofit Century variable speed motor (EVO 2.25hp) to replace a 13yr+ old single speed motor on my Sta-Rite pump. The kit included a new impeller, diffuser, seal. The problem I've been seeing is the pump won't start by itself unless an Allen key is first inserted in the back of the motor and the shaft rotated slightly. (The shaft itself does rotate freely btw). This has happened to the "first" new pump as well as its warranty replacement...
I rechecked the mains connections and took some current measurements with a clamp on AC ammeter: Clean 120v L/G, 240V L1/L2, doesn't droop at all on start. When it attempts to start, the unit draws 270mA for 5s or so, then (a relay or something) clicks softly and the current drops to 250mA. This cycle continues for some minutes before it times out and the LED control button flashes 4 times to indicate a seized shaft. If I power off, rotate the shaft slightly, then power on, the unit will soft start up to full prime speed, with the current draw eventually reaching 6.8A. It'll run all day once started, then be stuck the next morning.
Seems as though the unit's "soft start" is so low torque that it can't overcome the token startup friction between the impeller and diffuser (which came matched in this kit btw). Does anyone have background on whether such small startup current measurements are typical or a sign of a defective unit? Anybody experience something similar?
Thanks in advance for any advice here!