Sullair Ammonia Compressor

[nh3wizard]

I have 2 differnt Sullair ammonia compressors with no type of functioning capicity control, does any have any ideas?

[US Iceman]

Are they the C series, A series, or B series machines?

Are the electric motors broken or what? Please provide a little more information please.

[nh3wizard]

They are both are B series boosters, the electric motors for what is considered the capaicity control (butterfly valve)have long since been removed and have been adjusted by hand to try and adjust the suction pressure, but with air units getting satised in the evening hours it runs into a deep vacum, was wondering if a vfd for the compressor motor would do the trick but with the mechanical oil pump that poses a problem.

[Andy]

They are both are B series boosters, the electric motors for what is considered the capaicity control (butterfly valve)have long since been removed and have been adjusted by hand to try and adjust the suction pressure, but with air units getting satised in the evening hours it runs into a deep vacum, was wondering if a vfd for the compressor motor would do the trick but with the mechanical oil pump that poses a problem.

VFD's would work, but why not just replace the capacity vane motor with a new motor from say a stefia valve.

Are these compressors rotor vane

Kind Regards. Andy

[nh3wizard]

They are both screws

[Andy]

Hi nh3wizard

butterfly valve

On a screw

now I see why you are not for replacing them.


If you want to go VSD you are restricted to operate between 35 and 55 or 60hz. It will work well and efficent but may not give the degree of control you need.

Kind Regards. Andy

[US Iceman]

Why in the world are you letting the compressors run into a "deep" vacuum? Why not shut them off?

Why were the electric actuators removed? Were the valves sticking?

A VFD could be used if the oil pump is a full time pump, and not just for pre-lube.

Is your plant manually controlled or using a "control system"?

Note to Andy: The Sullair B series compressors are booster compressors only. They do not have slide valves or poppet valves for capacity control. The butterfly valves were mounted on the compressor suction. When the suction pressure decreased the valve throttled close to control the suction pressure.

The valve was 100% closed for starting to allow the rotors to spin up to full speed before loading the compressor.

[nh3wizard]

Untill recently we didnt have any other boosters at that location so we we had to use these with mechanical controls, someone in the past had stripped all of the wiring and acuators, dont know why. This is a good running machine in the heat of summer, which I then can use it as a lead machine and have the new screws we put in run the trim. These are the only 2 machines we dont have on our control system. Thanks for all the good input.

Gary

[Andy]

Untill recently we didnt have any other boosters at that location so we we had to use these with mechanical controls, someone in the past had stripped all of the wiring and acuators, dont know why. This is a good running machine in the heat of summer, which I then can use it as a lead machine and have the new screws we put in run the trim. These are the only 2 machines we dont have on our control system. Thanks for all the good input.

Gary

actually the inverter machine or in your case possibly two would be the most effcient to use for trim, keep the slide up on the others, any screw will be more effcient like this, but using the older, possibly less effcient compressor for trim would help the overall plant effciency (reduced electrical consumption)

Kind Regards. Andy

[Andy]

A VFD could be used if the oil pump is a full time pump, and not just for pre-lube.

.

But not on the oil pump

Kind Regards Andy

[US Iceman]

Right you are Andy.

Let me use a few more words to describe my original message.

If the oil pump is a separate pump and this pump is driven by a separate motor and this pump/motor is sized for full time operation the compressor motor can be driven by a VFD.

Sullair has several ways of dealing with oil flow. In some cases they used a part time pump for prelube only. In other cases, the external pump could be setup for full time oil lube.

Under no circumstances should any external oil pump be installed with a VFD!

[US Iceman]

nh3wizard,

If the butterfly valves are still in good condition and rotate freely you can still get parts for these.

Odds are you have an electro-mechanical control panel and most of the controls are still there (unless they have been removed also).

If you are interested in checking this out, send me a PM and I'll forward the contact information.

Sullair is not in the refrigeration business anymore. However, a bunch of ex-Sullair people are still providing parts and rebuilt compressors. Might be worth looking into.

[jmo422]

I was wondering what you mean by the acronym VFD.

Thanks

Jmo422

[US Iceman]

VFD = Variable Frequency Drive

You might also hear reffered to as varibale speed drives (VSD's) or Variable Frequency Drives (VFD's) or sometimes just as inverters.

They are electronic devices used to electronically change the speed of the electirc motors by changing the cycles (or Hertz) of the electrical supply.

[RANGER1]

Right you are Andy.

Let me use a few more words to describe my original message.

If the oil pump is a separate pump and this pump is driven by a separate motor and this pump/motor is sized for full time operation the compressor motor can be driven by a VFD.

Sullair has several ways of dealing with oil flow. In some cases they used a part time pump for prelube only. In other cases, the external pump could be setup for full time oil lube.

Under no circumstances should any external oil pump be installed with a VFD!

Why do you not recommend VFD on oil pump?

[US Iceman]

You could loose oil pressure if the pump slows down. And, I feel the potential energy savings are not worth the efforts that might be needed to make this work.

Just my thoughts only...

It could probably be made to work, but I prefer to choose my battles where there are some major gains to be made.

[Sullair Refrig]

If you are still looking for Sullair B Series actuator info please contact Mid-States Refrigeration