Trumpy, thanks for the comments.
Those 'Starrett' speed meters appear on E-bay auctions regularly -mint 1905 onwards models seem to go for only US$10-20, and are a boon for analysing induction motor performance, (ie find slip,frequency). Hard to use at first, as you know, co-ordinating beween the stopwatch and engage/disengage, but I average over a few goes.
I chose 2 motors for several reasons: Firstly I'm on the end of the power-line, as you can see, and have a real problem with volts drop- I never get more than 227v, less when all the district milking-machines start up! This limits the amps I can draw-I only have 40A to the shop. If you calculate 4A/hp sph ind. motor start without load, I'd need at least 24A to start the Alternator even on full 240 volts, and you khow what happens to Amps when volts sag.... So by starting the set on one motor, part load, I draw 16A or less. Once she's running, I fire No 2. Also, I had one 3hp-motor already, and 3rdly a 6hp sph. ind. motor is a rare beast here. Even with the set up shown, all the fluorescents drop out on start, and I've put in a few tungsten bulbs so's not to be plunged into darkness. I'm not pushing the alternator to its capacity- I reckon I could put 2x4hp motors on, if 'her-indoors' sanctioned it, but my mate from Perkins is now looking out for a small electric-start diesel, say out of a digger. Then I can run the big panel saw on 3ph too; I've got the motor- Felder sold me a sph motor replacement when I renovated it, but it's underpowered. The fire extinguishers are a must. In fact the shop has three, which aren't all shown in the pics. Shavings are a real fire hazard, and I've got a wood stove....
Alan
