Hobart 2812 Sometimes spinning backwards

[ectofix]

I don’t know what you mean by finding the capacitor to be dead.  What did your test of it indicate?

[eritech1]

I tested the µF . And tested 0 , suppose to be 189-227 

i installed a new one and hoping that solves the issue!

[fixbear]

First I have to know what type of case the capacitor has.  Black plastic or metal.  Second, how did you test it and what did you use.

 

If a split phase or capacitor start motor, it very well can run  backward with a bad cap or start switch.  If a PSC motor, not likely.

[eritech1]

It’s a black round plastic start capacitor , I have A DVM UEi dl429, that u can test µF.

So I think this slicer has a split phase motor but how does  A bad cap make it spin backwards?

[fixbear]

Ok, check the centrifugal start switch.  Often they get spark burns or wear from the armiture and out of adjustment. It is closed for starting.. Unfortunately I don’t think you can buy Flexstones or point files anymore.  So a dollar bill and a little fine abrasive compound is about the best you can do at cleaning them

[ectofix]

It’s THIS:

 

 

 

 

 

 

 

Hobart part number 00-070487-00026 

 

 

 

 

 

 

 

 

 

 

 

 

Sound like you got it, eritech1.

 

The only other component to affect the motor start would be the electronic start switch:

 

 

 

 

Hobart part number 00-271612-00002 

 

 

 

 

 

 

 

 

Both of those are a PITA to get to to functionally test, so I’d replace BOTH while you’re in there.

 

Here’s Hobart’s latest manual (2017):

CATALOG OF REPLACEMENT PARTS MODEL 2000 SERIES SLICER 

[ectofix]

I’ve never taken any of the motors apart in OUR 2812s, but I don’t think they have a centrifugal switch in them.  They’re probably an solid state version of start relays for common refrigeration compressors.

[ectofix]

Hearing about single-phase induction motors running BACKWARDS has always been a mystery to me.  I’ve worked on MANY motor-driven units, but have never seen it myself.  Therefore I can only suspect the start components as being the culprit.

[fixbear]

I can’t tell if that is a current or a potential relay.. But if potential, it has to be indexed dead level to work correctly.  I still have a problem with how you tested the cap.  You can only test one and measure the micro-farads with a dedicated capacitor tester. And they are not cheap.  Hell, I don ‘t even own one.  I can check if a capacitor works, but I can not measure how many uf it is capable of. That requires a very specialized machine/ instrument. You can test with a Ohm meter if the capacitor works, but not it’s value.  First you must discharge it for both safety and test reasons. Then connect a analog ohm meter and watch the needle.  It will sweep from 0 to infinity.  now reverse the leads and it will do it again

 

To actually measure the capacitor requires a programed power input supply, and a measured load output.  Handheld DVOM’s can not achieve this requirement.

[badbozo2315]

Naa, it’s a solid state switch. I’ve let the magic smoke out of a few over the years…

 

And most good meters these days will do temperature, frequency, and micro farads. Even my little one does DC clamp measurements. Cool stuff…