Power went out then back on and mixer reads err and 12 in the timer turned breaker off then back on still reads err

Check the power cable. It may have been kinked and shorted. Check if any of the internal switch or connectors are touching the body of the mixer. Some moving parts maybe stuck or dislodged due to the horizontal placement.

When your stand mixer does not turn on the problem might be a lack of electrical power, broken wires or a failed motor or control problems. First, check the outlet's GCFI breaker and reset it if it's tripped. If the mixer still won't work when plugged into a working electrical outlet then unplug the mixer and check the power cord.

Copy following link to determine correct wire and circuit breaker size:
http://waterheatertimer.org/Color-codewire.html
http://waterheatertimer.org/How-to-replace-circuit-breaker.html

Be sure to match wire size and breaker amp rating so breaker will trip when heat on wire reaches trip point.
Undersized breaker, or undersized wire are fire hazard.
Maximum 12 boxes per circuit breaker.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

If you remove the meat grinder, does the mixer still work? It could be that the meat grinder is jammed.

You might have also blown a breaker. Have you tried plugging a lamp or something else into the outlet to make sure it's still working?

I have decided to return the west bend stand mixer since it has never been used and get another brand.

how do you know diagram is wrong , you could have wired it wrong the timer kit i belive comes with 3 or 4 different diagrams for that mixer you need to pick the right one

You need to get a new electrician; a real electrician would read the power requirements on the motor name plate and install the correct voltage and amperage circuit.

A single pole breaker does not supply the same voltage as a double pole breaker. It hums because the voltage is wrong

this a 115 volt single phase timer you can buy the timer at hobart.com or jump the timer by jumping the red and brown wires but the timer will not work if you want the phone # of hobart tell fixYa to email me and i will leave the number they are located in jackson hieghts N.Y

There is only one bearing in the back a an A200, the rear motor bearing. Page 12 -- Otherwise I'd look for something rubbing the motor. (wire, capacitor shield) The two back side covers are easy to remove, two screws each.

http://www.hobartlink.com/extranet/extranetmanualsandcatalogs.nsf/57866D624A678E7385256CB0007232DA/$File/F-19357%20(05-95).pdf

The timer is also in the link. The part is not cheap, but easy to install.