View Full Version : Sab163 HF unloading problem

20-03-2017, 08:58 AM
Dear all,

Sab163hf not unloading. I checked slide valve, NO,NC solenoid valves, position transmitter every thing fine. When comp. goes to 100% and then try to unload but not unloading. On 80% or less compressor unloading.
Please suggest me what to do more.

20-03-2017, 09:06 AM
When compressor continues run the low pressure warning on unisab II . For cross check I closed throttle valve on unloading EVM. Capacity remain on 100% then stop compressor I throttle to open then capacity being uploaded.
Even on 100% compressor stop then compressor unloaded from 100%.

20-03-2017, 01:56 PM
There is three things
One your current if goes high than you set
Another is you low pressure stop you go for more load
3)your volume capacity in slide valve

20-03-2017, 08:16 PM
Hi Shaaf,
this is very often on this type of compressor.
When you reach 100% slide stop(volume) and capacity slide meet and stick like with glue.
Sometimes problem is dirty oil or mineral oil used.
Solution is to make modifications in compresor.

best regards

21-03-2017, 02:48 AM
How many hours on compressor since last device?
Had similar problem, ended up being one of the solenoids not operating correctly.
When compressor turned off in loaded position, unloading occurs not through solenoids, but a small non return valve in unload pushrod, in discharge port (202 machines)assume the same for 163.
Mother possibilities could be slide valve or guide wear.

21-03-2017, 06:07 AM
Compressor in stop position unload via same way through unloading solenoid valve. Because I stopped throttle valve before stop compressor and compressor remain same position where it was stuck during running. After ten minutes I throttle to open and compressor starting to unload.

21-03-2017, 09:33 PM
Shaaf, are needle valves on solenoid block fully open?

If you manually bled oil from cylinder while it was loaded by loosening fitting , see if unloads.

What system do you have for slide valve indication?
Is it rotating dial or linear position indicator, is it ready correctly?

22-03-2017, 05:18 AM
Yes needle valve on unload side fully open.
For slide valve indication linear position indicator.