Most likely, the Motor will never achieve full rated speed, but remain around 85% of that speed.
If the shaft has no load on it, the Motor might survive as long as 2,3,4 or 5 Hours before flames take over and fry the start circuit.
Loaded shaft will result in rapid OCPD trip, or loss of smoke, or BOTH!
All depends on the Motor its self:
* can heat be sinked rapidly,
* is the start winding tweeked for heavy/hard starts or simple starts,
* is the R/XC of the start winding going to result in higher current draw when motor achieves full speed, or will it taper off to a fixed value,
* and some other techee stuff!
Normally, a 1Ã˜ Split Phase Induction Motor will have a "Fixed Load" on the shaft - so the typical result will be smoke production within 5 minutes or less.
Motor will be restricted to < 90% of Rated Speed while under load (speed will slip behind Synchronous speed depending on load, and with start circuit locked in, speed will never exceed < 90% of the slip speed).
I REALLY hope this is not an exam question!!!
p.s. edited summ speleeng air-ers!
[This message has been edited by Scott35 (edited 12-04-2003).]