Hello, I have been installing Honeywell zone systems for quite a while (with the exception of the Intellizone panel when installing a Water Furnace). Please note that most of these installations have taken place near the coast line (within a mile) and do not get direct salt air but are in a more corrosive environment then other areas. I originally used 2 wire, spring/open power/close "ARD" dampers (properly strapped duct work and not placed at the bottom, handle clear of obstructions). I experienced an extremely high failure rate. There was no sweating occurring because most of these systems have been installed in encapsulated homes that are spray foamed, intake air for home pressurization only (conditioned attics with approx. 0% duct loss). I switched to using Honeywell "MARD" dampers on all zone system installations (3 wire, power open/close) and got better results but still have some failures, more than I should. I am very big on eliminating call backs and am "O.C.D." about the materials I use. I don't think I have made the right call here though; I found the installers guide online but it is different then the one in the box but the "ARD" motor if I could remember correctly could handle 16 lbs. of torque, "MARD" was somewhere around 32 lbs. which is plenty for my applications (the torque ratings are from memory but I think they are very close to accurate). I know that I am installing the "MARD" motors correctly and even if I wasn't they are designed to stop when the force exceeds the amount of torque they produce, this is why you can insert a pin at the 45 degree stop point etc. (I think that a clutch begins to allow the motor to keep spinning as well). The cost is about 3x higher for the "MARD" and when completing a conversion (service call) on a "ARD" to a "MARD" I have to purchase a 10" assembly because Honeywell doesn't have a part number for the shaft adapter. I don't care about the cost if I knew it would reduce a call back and keep my customer happy but it's not;
One example home; I have (14) MARD damper motors in a home that I installed when I replaced (3) 5 ton systems (all zone systems of course). I didn't complete the duct work (other than replacing the motor assemblies and bypass ducts) but it was close to proper sizing (not that it matters to the reliability of the motor). Long story short, I have replaced 5 motors in 2 years which is unacceptable to me. I am using an SPC control in part with the MARD and it works well but I get buzzing noises from a motor mounted on the top prior to failure (we now replace these during P.M.s to reduce call backs even though they are still operating). Even new motors are sometimes louder than others. I thought I was doing the right thing by spending the extra money on the "MARD" but I am still having issues and I don't want to learn the hard way with another damper motor made by another manufacture without advice. I may give up Honeywell's zoning all together. On another note, I have also experienced ECM motor "hunting" in some rare cases with the SPC controls which I was told by Honeywell would be eliminated by the SPC over a Barometric bypass (I have fixed this by adjusting cfm very slightly out of the desired range but not enough for it to pose any problems or efficiency concerns). Anyone have any recommendations of a good reliable motor and/or assembly. I am not too concerned about cost because most of the homes I complete are large scale residential homes that take 3+ years to complete have the budget to use the best of the best in materials. Regardless, I would like to have a low and a high end product line to be competitive. Also, anyone had any good luck with Honeywell's "True Zone Bypass (CPRD)", I think it was recently released? Hopefully more manufactures will start releasing zone boards that work similar to the Intellizone to control the ECM directly. Sorry for the large post, these motors have been driving me nuts and I want to see if anyone else is experiencing these same issues with Honeywell as well as find another product. I complete a lot of zoning, sometimes when my A.E.D. assessment exceeds 35% or when the application just fits it better. Thanks in advance!