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Originally Posted by Hoopstir

Correct me if Im wrong but this pressure controller is not a solid state control. This one has two sets of contacts and has a drive open circuit and drive closed circuit. Completely mechanical.

I would need an analog style output to give the drive a 0-10 or 4-20 input signal.

Im not sure how i would integrate the original control to the drive. I think I have to supply a static sensor that will give me an output. Or at least some controller that would do so. Which would in turn be accurate compared to this archaic device.

I do have a BAS I could tie a static sensor to and create a PID loop to give it an output.

Get a ABB VFD and use the floating control for that unit. I'll check my wiring diagram for that unit later.

Mechanical or pneumatic ? Is there a pneumatic actuator that drives the guide vanes ? If it's been updated through a BAS they would have used a transducer.

I have AHUs that use pneumatic receiver controllers and are very accurate.

Correct me if Im wrong but this pressure controller is not a solid state control. This one has two sets of contacts and has a drive open circuit and drive closed circuit. Completely mechanical.

I would need an analog style output to give the drive a 0-10 or 4-20 input signal.

Im not sure how i would integrate the original control to the drive. I think I have to supply a static sensor that will give me an output. Or at least some controller that would do so. Which would in turn be accurate compared to this archaic device.

I do have a BAS I could tie a static sensor to and create a PID loop to give it an output.

Originally Posted by Hoopstir

I have not at this point. I was hoping to have some creative yet less expensive options from all of the guys on here that may have ran into this one.

I do believe you may be right about this.

It would be a way more accurate method as well.

Unfortunately the tech before me found the static pressure control was not responding and we replaced that which was HIGH priced and of course I change it and see all of this visible things. I would have weighed all the options and went with the vfd from the get go. I understand its hard to look forward when you know you found one thing wrong.

Thanks for the advice. Time to sharpen the pencil

You would still need your HIGH priced transducer with a VFD.

It's tough when the customer thought they got a price on the fix. They thought that's all they needed. Now your in the position, that you know it's not fully fixed. And trying to find a way to fix it with the least amount of cost to the customer at this time. Is that really helping your customer?

I have not at this point. I was hoping to have some creative yet less expensive options from all of the guys on here that may have ran into this one.

I do believe you may be right about this.

It would be a way more accurate method as well.

Unfortunately the tech before me found the static pressure control was not responding and we replaced that which was HIGH priced and of course I change it and see all of this visible things. I would have weighed all the options and went with the vfd from the get go. I understand its hard to look forward when you know you found one thing wrong.

Thanks for the advice. Time to sharpen the pencil

Originally Posted by Hoopstir

I suppose erratic static is a better description for the term. They aren't sticking though.

They start to move and then get to a point and due to the slack in these bushings they make it to a point and just flop open about 2" causing "erratic static" resulting in a surging sound to the customer.

I dont think I need to remove all the vanes. just the clips and the bushings on the outer wheel which are the end of the vane linkage. I think this would get things back to a reasonably functioning system.

I would love to do the VFD however. It would provide some ROI as well. Something I will work up as a bid for certain.

I'm not sure if you ever dealt with this before or not.......but I have never been able to replace the bushings, without pulling the vanes(don't know your particular unit). Also, the ring around the shaft normally is worn out, because of the binding.

Have you priced out a VFD? A 30hp drive is not that far off from the labor of replacing the bushing, inner ring, and possibly some vanes.

I suppose erratic static is a better description for the term. They aren't sticking though.

They start to move and then get to a point and due to the slack in these bushings they make it to a point and just flop open about 2" causing "erratic static" resulting in a surging sound to the customer.

I dont think I need to remove all the vanes. just the clips and the bushings on the outer wheel which are the end of the vane linkage. I think this would get things back to a reasonably functioning system.

I would love to do the VFD however. It would provide some ROI as well. Something I will work up as a bid for certain.

Originally Posted by Hoopstir

Model 48DKD064--A series 600SM


I have a set of inlet guide vanes that have a series of white plastic bushings (11 per side) on the outer ring of the assembly that hold the armature which turn the vanes. They are at the end of the blades that poke through the outer ring.

These bushings are worn out and causing these vanes to flop around and are not able to control the vanes in a steady way causing air surging.

I have tried my local carrier parts and they have not been of any help. Does anyone know of any way to purchase these or even use some other material to get the extreme slack and play out of these.

I know the easiest thing is to put a drive on it and remove them but that is very costly and the customer didnt seem very responsive to that idea.

Any help would be appreciated

You are getting air surging?

When the bushing wear out the guide vanes normally stick. And you will get erratic static.

The labor involved to try to pull all the vanes out to replace the bushings.....is pretty equal to a VFD install, these days.

CARRIER - Inlet Guide Vane problems

Model 48DKD064--A series 600SM


I have a set of inlet guide vanes that have a series of white plastic bushings (11 per side) on the outer ring of the assembly that hold the armature which turn the vanes. They are at the end of the blades that poke through the outer ring.

These bushings are worn out and causing these vanes to flop around and are not able to control the vanes in a steady way causing air surging.

I have tried my local carrier parts and they have not been of any help. Does anyone know of any way to purchase these or even use some other material to get the extreme slack and play out of these.

I know the easiest thing is to put a drive on it and remove them but that is very costly and the customer didnt seem very responsive to that idea.

Any help would be appreciated