My Miele Callisto canister vac motor doesn’t turn on when the switch is turned on. I checked voltage in each of the 3 wires that plug directly into the motor housing receptacle. When the switch is turned on I am measuring 120v at each of those 3 wires but the motor doesn't run. When I bypass the motor’s triac in a bench test it does run. The triac however tests good with a reading of 070 across legs 1 and 3, and 1 across legs 1&2, and 2&3. I'm stumped, what is left to test?
Miele vac motor diagnosis
- Thread starter Cascadel
- Start date
One probe of my multimeter was connected to one of the 3 motor supply wires and the other meter probe was connected to the ground wire of a plugged in 3-way extension cord. I used this setup because I wasn't sure which wire was the neutral. I was very surprised to find all 3 reading 120v. Note - the 3 wires were not plugged into the motor when this test was performed. There was no 4th wire neutral.
Ok, I figured out which is the neutral wire. I'm not seeing any current flow from black or red feed wire when connected to neutral wire. I tested the reel feed and neutral and am getting 120v across them. I'm assuming therefore the circuit board has a short in it. Sound reasonable?
Any guesses as to why I am seeing 120v on the neutral vac wire (that would plug into the motor) when my multimeter is attached to my extension cord's ground wire (for test purposes) but 0 volts when I connect the meter to the vac's hot wire (that would plug into the motor) and the same neutral? Where is that 120v coming from?
Not being able to see your appliance or a circuit diagram I guess that you are reading 120v that has passed through one of the coils to your meter to earth and the the problem is a broken neutral wire in the supply cable. Do a continuity test on all cores of the cable.
Thanks for the helpful continuity test suggestion. I discovered the neutral wire feeding into the cord reel has no continuity with its blade at the plug end. Since that neutral wire was showing a voltage of 120v where it plugs into the motor I'm going to assume it shorted across the hot supply wire inside the reel. Hoping I'm right I've ordered a replacement cord reel.