Perran has kindly written another article for us about Prescott and also the Motor Protection system on the C5.

http://www.c5owners.com/sinclair-c5-history/stories/prescott-testing-and-c5-motor-protection

Special thanks to Perran for taking the time to write the article for us!

That's a great article many thanks to perran

Nice to read something from the designers end.

At last some support, from someone who people will listen to, for my warnings concerning heat and electric motors. One thing he didn't mention is the effect that heat has on the efficiency of electric motors, as heat increases so the magnetic field from the magnets decreases.

At some time or other there will be no more original motors available. So if you ever dismantle your motor you should improve the ventilation at the gearbox end, regardless of if you live in hilly or flat terrain. An electric fan is a good idea, preferably temperature controlled, so long as the airflow goes through the motor and not around it, e.g. one of Dan's motor mounts. One quick and simple help to dissipating heat is to spay the motor body matte black, heat resistant paint is available for spraying exhaust pipes.

As pointed out by perran, the thermistor is essential to protect the motor and not just a gimmick. The motor will run with the thermistor and motor body heat sensor removed, but then the motor protection is also removed.

So look after your motor, after all it's the C5's heart.

Interesting read. Many thanks to Perran for taking the time to write from memory. Keep it coming.