Discussion Category:  Lab Furnaces

Furnace not turning ON.

I have a Lindberg/Blue M box furnace (Model # BF51842PBCOMC-1) with the UT150L and UP550 controller. All of a sudden, the furnace has stopped turning on. To turn in on, I hold the RESET button on the UT150L controller until the OUT lamp on the controller goes OFF and the furnace's main lamp turns ON. Now, the OUT lamp does go OFF but the furnace lamp does not turn ON.
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shubh4199
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avatar placemarkReply by
RichardB

Still having problems with this oven?  The oven operates from 220Vac, which can be dangerous.  Working on the oven, you do so at your own risk.

Your description is confusing because the manual I find for this oven specifies that the BF51842'P'BC uses the UP550 controller, while the BF51842''BC (no P), uses the UP150 controller not a UT150.  But you mention that an OUT light which only exists on the UP150 not he UP550.  So, I will assume you have a UT150 because the UT150 because it has a setting that could cause on of your problems.  First, you need the manual for the controller and read through it.

https://web-material3.yokogawa.com/IM05C01E22-01E_070.pdf

It sounds like you now have multiple issues:

1) The OUT lamp being on when the furnace is turned on. In the above manual, page 4, Power On Status, mentions a setup parameter, R.MD, is set to '0' that could accouunt for this.

2) The furnace 'heating' lamp not turning on.  Could not find a reliable wiring diagram for the given model but experience says:  this could be caused by multiple things.

* A solid-state relay is controlled by the UT150 - it may not be getting the voltage signal from UT150.

*There is likely an over-temp safety monitor that controls a mechanical relay (also called a contactor).  The relay is not closed because the over-temp is tripped - possibly an open temp sensor.  Or, less likely, the contacts on the relay are bad.

* There may be fuses inside on the power feeding to the heating elements.  One or both ar open.

There could also be wiring that burn open. but these are thngs to first look at.

 

 

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avatar placemarkReply by
shubh4199

I have a UP550 and UT150L controller. The issue, I think, is that I turned off the 4 Alarms in the UP550 controller and I need to input the correct numbers (Can be between 1-30) for all four alarms (AL1, AL2, AL3, AL4) to turn the furnace back on. 

The way the furnace works is that I need to press the RESET button on the UT150L controller until the OUT lamp on the UT150L controller turns OFF and the furnace lamp turns ON. So, R.Md being on 0 is correct. 

I do not think that this is a hardware issue because the furnace was working fine and it only stopped working after i changed the settings. 



 

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avatar placemarkReply by
shubh4199

I have a UP550 and UT150L controller. The issue, I think, is that I turned off the 4 Alarms in the UP550 controller and I need to input the correct numbers (Can be between 1-30) for all four alarms (AL1, AL2, AL3, AL4) to turn the furnace back on. 

The way the furnace works is that I need to press the RESET button on the UT150L controller until the OUT lamp on the UT150L controller turns OFF and the furnace lamp turns ON. So, R.Md being on 0 is correct. 

I do not think that this is a hardware issue because the furnace was working fine and it only stopped working after i changed the settings. 



 

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avatar placemarkReply by
RichardB

Just wondering, why did you clear the alarm settings?

In order to figure out the settings, the wiring of the furnace and exact part numbers of the controllers needs to be known.  A manual for the furnace should have a wiring diagram - I have not seen a manual showing both the UP550 and a UT150L controller in the same unit.  How old is the furnace?

Temp controllers can come with options - so the whole part number needs to be known.  There is usually a label on the side of the controller that gives the whole part number.

Now things have to be reversed engineered in order to figure out what each alarm is for and how to set it.

A picture of the furnace part number tag would help locate the manual for the furnace. As well as the full part numbers of the controllers.

 

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avatar placemarkReply by
faulknernolan6320702_2745

But the main thing I want is the solution and the things to avoid

fall guys
 

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