Trane E series unloaders

[redback]

What is the best way to control the three capacity control solenoids on a trane e series compressor. I have one to fit and after some options.

[duke of earl]

I recommend suction pressure using 3psig increment. Example(R-22) Suction pressure target is 70, suction pressure falls to 67 then unload. Suction pressure increases to 73 then load.

[Allen]

Hi Redback,
What is currently controlling the loading and unloading.
Are you cooling air or water?

To load and unload that compressor by suction pressure now, you would need to change the handhole cover where the loader solenoids are.

If you use the existing loader solenoids, you could use a Honeywell W7100 for air or a Honeywell W7900 for water.

Good Luck,
Allen

[y7turbo]

Hi Redback,
What is currently controlling the loading and unloading.
Are you cooling air or water?

To load and unload that compressor by suction pressure now, you would need to change the handhole cover where the loader solenoids are.

If you use the existing loader solenoids, you could use a Honeywell W7100 for air or a Honeywell W7900 for water.

Good Luck,
Allen

No need to change the handhole cover, you can just use pressure switches to energize the electric solenoids. We have many set up this way..

To do by temperature you can also use one of the Honeywell T775 controllers. I forget the exact model number of the controller, but they work well too.

[ga1279]

Redback- Model "E" solenoids energize to load, de-energize to unload-GEO

[redback]

The compressor is cooling air in more than one air handling unit, each air handling unit has a liquid line solenoid coil and can shut down depending on zone temp for that air handler.

I checked the specs on a renco pressure control and has a minimum diff of 9psi a penn control minimum diff of 7psi, I would like to keep the SST between 30F and 41F on R407C but it would be difficut to set three pressure controls within such a tight range.

[softtail]

If the AHs are constatnt volume, use the mechanical suction unloader plate, not the electrical unloaders.

If a chiller or VAV AH, use electrical unloaders w/ discharge water/air controller.

[heatingman]

The compressor is cooling air in more than one air handling unit, each air handling unit has a liquid line solenoid coil and can shut down depending on zone temp for that air handler.

I checked the specs on a renco pressure control and has a minimum diff of 9psi a penn control minimum diff of 7psi, I would like to keep the SST between 30F and 41F on R407C but it would be difficut to set three pressure controls within such a tight range.

Use a T775 with an analog input and 3 digital outputs. Get a pressure transducer to tee into the suction line to send the analog signal to the T775.

Or just use three different pressure controls, and dial them in on install.

[ironman597]

I agree with softtail - Use the mechanical unloading plate and dial in. These compressors with the mechanical unloading work great and trouble free.