1. Cryogenic Plant Controls – Safety Switches
Robert Norton
Cryoplant Controls Hardware FDR
September 13, 2017 1

2. Emergency Switches
Are Emergency Switches adequately located on the panels, cabinets and throughout the plant?
Stop switches are located on the guard vacuum pumps. 2
Cryoplant Controls Hardware FDR, September 13, 2017

3. Emergency Switches
Push-Pull E- Stop switches are located on the recovery compressors. 3
Cryoplant Controls Hardware FDR, September 13, 2017

4. These switches are lockable.
Emergency Switches
External power disconnect switches are located on other enclosures fed by greater than 150 Volts.
These switches are lockable.
2K cold box test heater control enclosure 4
Cryoplant Controls Hardware FDR, September 13, 2017

5. E-Stop switches are located on the warm Helium compressors
Emergency Switches
E-Stop switches are located on the warm Helium compressors
Warm He compressor control panel layout 5
Cryoplant Controls Hardware FDR, September 13, 2017

6. Emergency Switches
Is the Emergency Switches logic defined (local switches and/or overall switches)?
Yes, for the recovery compressors this logic is defined in the wiring diagrams. Stop switches are hardwired to stop equipment operation. Requires pull-action reset.
In addition, upstream breakers are lockable. 6
Cryoplant Controls Hardware FDR, September 13, 2017

7. Emergency Switches
The external power disconnect switches remove power to the control enclosure in question, in this case, a heater control box.
Upstream breakers and incoming power disconnect switches are lockable.
2K cold box test heater control enclosure 7
Cryoplant Controls Hardware FDR, September 13, 2017

8. Emergency Switches
Emergency switch logic is defined in the wiring diagrams for the warm He compressors.
E-Stop switches are hardwired to stop equipment. Requires pull-action reset.
Upstream breakers and incoming power disconnect switches are lockable. 8
Cryoplant Controls Hardware FDR, September 13, 2017

9. Emergency Switches
Stop switch logic is defined in the wiring diagrams for the guard vacuum pumps.
Stop switches are hardwired to stop equipment operation.
Guard vacuum pump enclosure wiring 9
Cryoplant Controls Hardware FDR, September 13, 2017