I recently bought a blodgett ef 111 and can’t find the wiring diagram. Contactor new, no closing. Thermostat, check. Safety switch, check. Fuses, check. Capacitator, check. Heat element, check. What to do now? Please help. Thanks in advance.

[john]

Hello,

 

That’s a pretty old model! I couldn’t find a wiring diagram unfortunately, but was able to find a manual on our site: http://download.partstown.com/is-bin/intershop.static/WFS/Reedy-PartsTown-Site/-/en_US/manuals/BL_EZE_iom.pdf 

One thing the electrical connection page says is this:

You didn’t mention the blower as a checked item. Meanwhile, if I happen upon a wiring diagram, I will share it here.

 

-John

[ectofix]

I think John nailed it.

 

Not much has changed in Blodgett ovens through the years.  That electric oven is as basic as they come.  If the blower is running, but oven is not heating, a rare but possible cause is that the blower motor’s centrifugal switch isn’t closing or its contacts are worn out.  That switch is inside the motor and is normally OPEN.  It closes when the motor reaches operating speed and enables the heating circuit.

 

That’s a standard circuit design in just about ANY convection oven.  It prevents heat circuit operation if the blower isn’t running.

[masa]

So, that means that I have to buy a new motor or I can just change that centrifugal switch?  

[ectofix]

There’s no possible way I can tell you for sure that the problem is the motor’s centrifugal switch without personally looking at it.  John and I are simply simply saying that you didn’t mention whether you’d tested that part of the circuit.  Apparently you haven’t

 

The only possible way I could say for certain that it’s the problem is to be there with a VOM to troubleshoot it.  I can’t go upon you capabilities in using a VOM, nor do I know your level of knowledge in testing the components that you rattled off with a “CHECK”.  For all I know, you may simply have a faulty wire or connection somewhere that you haven’t found which may be the actual problem.

 

Here’s a link to a picture of one of the two possible motors used in that oven.  Blodgett part number 32244:  EF 111 Single phase motor

When I looked at that, my experience tells me that the two gray wires in that picture are probably the leads for the centrifugal switch inside the motor.  Therefore I’d disconnect those from whatever they go to, suspend the leads out somewhere so they can’t touch anything (just in case), then turn on the oven.  If the motor ramps up to operating speed, then those leads are probably the ones coming off the centrifugal switch and therefore have no link to electrical energy coming to them from within the motor.  At that juncture, I always use a voltmeter to be sure.  THEN…I’d connect an ohmmeter across those wires.  With the motor running, you should read continuity.  With the motor off and stopped, it should read ∞.

 

 

 

As for replacing the centrifugal switch?  That’s generally done by a motor repair shop.  You’d have to take the motor out and take it to them.

If you DO determine that the problem is that switch, you’re better off just replacing the motor.  If you’ve never removed a motor from a convection oven before, then you’re in for a real treat.

Well, I should say a special CHALLENGE.  Along with the necessary tools to remove the blower wheel…and some special tricks up your sleeve and OTHER special tools to cope with the wheel being SEIZED onto the motor shaft, I recommend having a new blower wheel on hand before undertaking that endeavor.

[masa]

I did the troubleshooting “by the book”, and I know how to use a voltmeter.  I’m no expert in this oven but the first thing I did was to find all the information I could. The image you send me is nothat even close to the motor this oven has. Mine is longer and the switch is inside the motor case. There’s to red, two yellow, one black and one blue. The ones feeding the juice for the motor are white with blue stripes and one white.

I just found that even with the circuit closed on the centrifugal switch is not heating. But thanks for all your support and help. I will let you know what was wrong.

[fixbear]

did you check the armature coil on the contactor?