Unloaders

[1tonn]

I have a Carlyle compressor mn#o6ET265360 208/230 v 3phase on a jobsite that has two unloaders, one on each side bank, 6 cylinder. Iam not sure if it is a hot gas or suction cut-off type unloader. I am going back Mon. AM to determine if the unloaders funtion correctly or even adjusted properly. The facilities mech. has been messing with them by screwing them in and out.
I have basic understanding of how they work but would like to first determine which type we have and the proper way to set them up. Any information would be appreciated.

[steveoo]

i tnink hot gas cut off has a 3 or 4 bolt plate on bottom of head,and bypass has unloader on top of head only,just remember the head closest to the disgharge is the last to unlaod,to keep saturated suction gas cooling the internal part's of compresser.I think the hex cap set's the unload pressure and the small screw under base control's differential pressure ,make sure your loaded up before you try to adjust.

[Failure2Comply]

Suction cut-off has plate on underside of head.

http://www.brainerdcompressor.com/06...tification.htm


Unloader adjustment:

"Turn the adjustment nut clockwise to the bottom stop. In
this position, the cylinder load-up pressure is 86 psig
(6.9 bar). Control set point is regulated to desired pressure
by turning the adjustment nut counterclockwise. The
number of turns can be determined from the curve in
Figure 15. Each full turn counterclockwise decreases the
load-up point by approximately 7.2 psi (.5 bar).
Approximately 12 turns changes the pressure from 86 psig
to 0 psig (6.9 bar to 1 bar). Pressure differential between
cylinder load-up point and unload point is adjustable from
6 psi to 16 psi"

Differential Set Point
Turn the adjustment screw counterclockwise to the
back-stop. In this position, the differential is 6 psi
(.41 bar). Differential is set by turning the adjustment screw clockwise. The number of turns to the desired differential
can be determined from the curve. Each full turn
clockwise increases the differential by approximately
0.8 psi (.06 bar). Approximately 5 turns changes the differential
from 6 psi to 10 psi (.41 bar to .69 bar)."

Page 36 of this document.

http://www.americanhermetics.net/ass...6deapguide.pdf

[Dallas Duster]

Suction cut-off heads look similar to a regular head but a HGBP head has an anchor shaped indenting on it. I'm sure it was probably suction cutoff.