I recently bought a 5XL on a Graves Mk IV base: This was from a deceased estate. The motor is a Leeson Electrical Corporation Model 970.070B, on which I can’t find anything on the website:90V, 60Hz
The machine was transported first in USA and then to the Warm (Dark) Hart of Africa, and is claimed to have worked when tested before shipping (in the USA); On connecting up the machine to a appropriate 110V supply (our local system is 230V, 50Hz) neither the motor nor light came on : A blown 1A 250Vac fuse was found in the fuse holder. I then added a small, 50 VA 230-115 voltage converter; It tested at 121V. On switching on with a replacement 1A fuse, it was blown, as was a 2 A (Current on running motor apparently is 1.1A, from a friend who owns one…); I then put in a 3A fuse, and connected the system to a much larger power supply, giving about 3KVA at 107V, thinking that the 50VA was not enough (although the old REA motor in my old,circa 1970,model Graves Mk IV runs off such a transformer; Peter Erdo of Graves advised that it would run off a 150Watt – 200Watt transformer
This resulted in another blown fuse:My question is: What do I check next? What can possibly go wrong on a motor without outward signs of damage to anything else, that could cause this? I’m no electrician by training, but through necessity has had to be one often 😉
By the way, the light was able to be switched on, when I fitted the 2A & 3A fuses, but would go out when I turned the speed-control unit to “ON”
Form a rather desperate Pierre le Roux in Malawi, Central East Africa.
your speed control was designed to work on 120ac 60 cycle for a u.s.a. machine. if you connected it to a 220 or 50 cycle you can blow the electronic in the speed control the motor may be ok. if you connect the leads from motor to a dc power supply above 25 volts to no more than 70 it shound run if good not damaged many of the machines use a perminate magnet motor for variable speed and unless the windings are burned out it should run. the speed controls are sensitive to wrong voltages and moisture. mike zinski
there are speed controls out there made in china on ebay that i have gotten that work great on perm mag dc motors. they run around $20 or so and can be used to replace burned out units if thats the problem. if you can you might check the motor brushes if easy enough to do for being worn out. any one having these prob’s get back to me i might be able to help. i think the ones i got they make one for 220 too as they are set up to accept ac and dc input power and dc out. firstname.lastname@example.org