Blodgett ovens

[puck]

I've been an HVACR tech over 10yrs,recently went to work for a company that does everything...or tries too. Yeah, even do kitchen appliances that's where my problem is.I can't recall exactly how you chk a flame rectifier ( excuse the spelling) I know you place the meter in series with the probe & ignition control module,but what type of reading should I get ? milli-amp, milli-volt, or micro-amp. thanks & remember...You can't fix-it if you don't know how it works!!!!!!

Puck

[d_griff]

I've been an HVACR tech over 10yrs,recently went to work for a company that does everything...or tries too. Yeah, even do kitchen appliances that's where my problem is.I can't recall exactly how you chk a flame rectifier ( excuse the spelling) I know you place the meter in series with the probe & ignition control module,but what type of reading should I get ? milli-amp, milli-volt, or micro-amp. thanks & remember...You can't fix-it if you don't know how it works!!!!!!

Puck

micro amps for a direct flame recitifier reading depends on manuf,usually at least 1 to 3 or more...28-32 millivolts for a thermocouple

[pipes6]

>0.6 micro amps on most blodgett equipment. we are a test site for blodgett and they have been having lots of problems call tech support @ 802 860 3700 for latest info.

[ReferTroop]

but if you can figure it out you will never forget it. Basically a Blodgett oven works exactly the same as a spark ignition furnace, just a bell or a whistle different. I've been doing them for 16 years and never once had a problem with the rectifier probe, always has been the ignition module, or the temperature contol board and once the pilot portion of the gas valve which wouldn't completely extinguish the pilot flame and consequently would not reset the module and not allowing the unit to return to the heat cycle. The later was very hard to find.
Not saying it couldn't be the probe, just relating my experiance.
A lot of this is caused by the cooling fan at the back of the control panel being plugged with debris or going bad. End up melting a module and so on, I still can't figure out why they have put integrated circuitry next to a 500 F oven.

JS

[ReferTroop]

>6 micro amps on most blodgett equipment. we are a test site for blodgett and they have been having lots of problems call tech support @ 802 860 3700 for latest info.

will put that number on file....

JS

[Dad]

There was a good link for an article on Flame Rectification. Unfortunately it doesn't exist anymore.

Here is a copy of the pdf file that I saved from it a while back. It does a really good job of explaining it.

You can also click on this link for a teaching session on this subject as well.

http://hvac-talk.com/vbb/showthread.php?t=63595&highlight=flame+rectification

[cybercontadino]

Make sure the flame probe is clean. Sand it down or wire brush it. Have had to do this more than once.
And don't forget to make sure pilot orifice is clean and flame is blue.
Those ignition modules can become really deformed and melted looking, yet they still manage to work...amazes me.
I change them anyway when they look like that.

[Dad]

http://hvac-talk.com/vbb/showthread.php?t=135634