MemberFebruary 12, 2020 at 10:13 am
So my convection fan is not running properly.
When set to high speed it sounds like it might have something in the fan wheel or that it is moving too fast, just a “bit off” and then after approx 30 seconds will turn off. If I keep the fan on low, runs continuously without issue with no consistent odd noises, there is an occasional “tink” noise.
Breaker not tripped, but I reset that anyway.
I haven’t gotten a chance to turn the oven around and do meter reads, or check anything since they are open for business, however I only have approx an 1.5 hours to work on it before they go back into business in the kitchen.
So I figured I would check here before blindly delving into it since the point of the low working fine and the high being an issue kinda confuses me.
MemberFebruary 12, 2020 at 11:44 am
Not sure what you have here. Be aware that there are several versions of the DFG. Multiple motors as well. If it is tripping the overload at high speed, There is something in the blower system causing a bit of friction. Often aluminum foil. But it can be grease and food build up.
Second thing is the motor bearings. When cool you can slowly turn the blade and feel how free it is and if there is any rumble of the bearing.
Alternately if your motor is a capacitor run like a PSC and may have a bad capacitor. Be aware that there is a mechanical centrifugal switch in the motor for flame lock out.
MemberFebruary 12, 2020 at 1:42 pm
So far I took the oven away from the wall and found a fair amount of dust covering the vent of the motor, so that was vacuumed out and the motor blown out with compressed air. Sounds much better at the low speed which it will run at. At high it also sounds better but it does sound like something is in the blower wheel.
The chef told me the previous guy had to take out aluminum foil sometimes.
So that would make sense. I will look at that.
MemberFebruary 12, 2020 at 2:15 pm
So I took off the blower wheel cover and vacuumed it, there doesn’t appear to be anything stuck in the blower wheel.
The wheel moves freely and doesn’t appear to have anything inhibiting movement.
I guess I can shoot de-greaser on the shaft to remove anything that might be building up.
But like I was saying earlier it the motor starts making noise at high speeds only, low speeds now it is quiet.
However I did notice when running the fan at high speed for the cool down feature and letting it run for about 15 sec then letting it stop it sounds like something is hitting the fan wheel.
Is there a better way at getting behind the fan wheel, doesn’t appear like you can unless you take the fan wheel off but the bearing on the end looks like you need a special tool.
MemberFebruary 12, 2020 at 7:02 pm
So I got a chance to open it all up, the capacitor works as it should, the correct voltage is being sent to the motor from both the low switch and high switch.
When the motor stops the voltage itself is still present so it seems that the motor itself is disengaging.
I already vacuumed the motor and found a scary amount of dust, I will be bringing down a compressor to “hose it down” and see if that resolves the issue.
Otherwise seems like the motor has failed.
But before I order a $500+ motor, any other ideas?
MemberFebruary 12, 2020 at 7:35 pm
- The capacitor IN CONVECTION OVENS is only for starting the motor. It obviously works.
- The centrifugal switch IN CONVECTION OVENS are designed to CLOSE when the motor is up to speed before enabling the heat circuit.
- Unlike OTHER applications (such as in a cloths drier), the centrifugal switch has nothing to do with disabling the start winding.
- SO…since the oven HEATS, that obviously works.
If it’s stopping on HIGH speed, but not on low – then it might be a bad high-speed winding. An amp draw test would reveal that. Refer to the motor’s spec sticker.
That motor lives a rough life from all the heat. The debris that blocked cooling airflow likely took a toll on it.
The noise you’re hearing MIGHT be the growl of a shorted motor winding.
Be aware that Blodgett has gone to a newer motor which will require some retrofitting on the wiring side of its installation. Instructions come with the motor.
SO…if ahigher than rated amp draw reading proves to be conclusive, then YES – the $500 motor will be necessary.
MemberFebruary 12, 2020 at 8:10 pm
Your second post was a good read. The 1st not so much.
Yes it is a bad motor.
Lucky that I found a replacement from another company that is not Blodgett for $130 shipped.
Looks the exact same, has the same specs and even states it is a replacement for the Blodgett 32291.
However, the current motor that is mounted to the oven is also not from Blodgett so I will likely find out, after cleaning the label fully who makes that motor since the wiring is already done up for this motor and it has been working for many years.
ectofix, thanks again,
MemberFebruary 12, 2020 at 8:41 pm
In light of that, I’ll try to avoid making 1st posts from now on.
MemberFebruary 12, 2020 at 8:33 pm
I love having spares. Now just gotta take off the old blower wheel….
MemberFebruary 12, 2020 at 8:45 pm
There are tricks for that too. I’ve had to CUT some off.
I always order a new blower wheel along with the replacement motor…just in case.
MemberFebruary 13, 2020 at 11:05 am
Someone in our chain of facilities had a bearing pulls that is fantastic and that was only about 15min, lordy there is a lot of screws and sheet metal on this oven.
After about 3 hours, got the wheel off, motor out, new motor installed with the wheel and have it running.
Like a champ I might add.
AdministratorFebruary 13, 2020 at 11:18 am
I love it when a plan comes together!
MemberFebruary 13, 2020 at 12:16 pm
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