Make up air controller

[gman994]

I have a makeup air unit that is utilizing a Maxitrol A1044 / MR212 burner control arrangement. There has been discussion of including this unit into a Building Automation Sytem, which would require removing the amplifier and installing a Maxitrol signal conditioner that would convert the BAS control signal to a DC voltage compatable with the MR212 for modulation. I've seen this done before, but with less than desirable results. I didn't know enough about the BAS controller to do much about it. Does anyone know of a way to convert the BAS 0-10vdc to a resistive signal that the amplifier recognizes? I really like the A1044 system, it works. I think it would simplify things to retain it and send a signal simulating a Selectra.--- Thanks for any ideas.

[fxb80]

I just replaced controls on a system that has 0-10vdc from the BAS being converted with Maxitrol signal conditioners. Actually there are three heaters in series, each with it's own controls. It replaced a system that had been there since '95 with the same setup. I would be interested to know what "less than desirable results" you have seen. There were problems to resolve on this job but they had more to do with the inherent limitations of the equipment rather than the controls.

These units had two components in the heater modulating the burner, the MR valve and the signal conditioner. If you do it with an amplifier there will be three components, the MR valve, the amplifier, and the volts to resistance converter. Seems more complicated.

[bc guy]

Had a building that used one of their products that did what you might want.

http://www.act-solutions.com/ICC/ICC.shtml

It may have been this one controlling the maxitrol modulating vdc gas control valve directly
http://www.act-solutions.com/ICC/pdfs/asa/asa_spec.pdf

If you call them they should be able to match what you want.

[james mo]

Designed for use with the Maxitrol Selectra®
series of modulation systems — or SC10
Signal Conditioners convert computer/PLC
controller signals if standard Maxitrol companion
controls are not specified.

Here is a link to the Mr212 manual...Call your maxitrol rep and they can provide what you need.
http://www.rapidengineering.com/pdf/third_party_literature/Maxitrol/Maxitrol_MandMR_Valves.pdf

[james mo]

I think this is what you need..http://www.rapidengineering.com/pdf/third_party_literature/Maxitrol/A200_SignalConditioner.pdf