1) Turning OFF: Push this circular knob (red)

2) To Restart:

If outside tank pressure > 120 psi.
This can happen when performing a magnet fill which cause capturing boil-off helium with a faster rate. Therefore, checking the outside tank pressure before a magnet fill is necessary.
Avoid the outside tank pressure reaching 120 psi, by
i) Venting gHe from the outside tank when it is around 110 psi or below.
ii) Liquefaction
If it happens, then perform (i), then unplug/plug Kaeser Compressor (NOT HR3 power plug), or wait for a couple of hours to let the Kaeser Compressor to start automatically.
If PC1 < 0.1 psi
This 0.1 psi can be changed using the ProSense cube on the HR3.
If the buffer tank pressure (VSWR) doesn’t increase by 1 psi within a sample time of 10mins.
This is a setting on the LCD panel on HR3
Press F5, and then Press F1 to navigate to that screen, then use F3/F4 to increase/decrease value.
If the compressor (Kaeser) did many starts in a short period of time (6 + / hour).
If this happens, then unplug/plug the HR3 power, then it will start automatically.
If there is an alarm on Kaeser compressor.
In this situation, Kaeser compressor’s screen needs to be checked.

Date	Person	Note
07/05/2022	Sam	“ The main reason why the compressor wouldn’t start is if the system is at maximum pressure already or if it did many starts in a short period of time (6 + / hour I think). The system would instantly restart when PC1 > 0.7 even just after it stops due to a lack of pressure rise in PSW4.”
08/09/2022	Sam (and Ishara)	Buffer Tank Max Pressure was set to 250 psi (max allowed although Sam asked to change it to 999 psi).
07/28/2022	Adam	“ The check valve here acts as a pressure maintaining device. For example, in a situation where the storage tanks outside are empty. This check valve keeps a minimum of 50 psi in the HR3’s loop and buffer tank. When the pressure in HR3’s buffer tank reaches 100 psi, the solenoid valve SV7 will open, allowing free flow from the buffer tank to the storage tanks. This will discharge the buffer tank quickly until the pressure reaches 80 psi, then it will shut. It will keep doing this until the pressure in the storage tanks outside go above 80 psi at which point the lower set point will never be reached and SV7 will stay open. “The clicking that you hear from the HR3 may be the sound of the buffer tank unloading to the storage tank. The higher the incoming flow to the HR3, the higher the frequency of the clicking sound”. “ This model of recovery compressor is rated for 53 scfm at 125 psi. Any incoming flow above 53 scfm will be vented, but the compressor will continue to run and recover 53 scfm.”