Ulvac EGL-206M Instruction Manual page 22

(9) Wiring of flow switch
Connect the flow switch contacts to the GUN WATER interlock circuit of the
electron beam gun power supply.
If there is a heat source (for example, resistance evaporation source) near
the EB gun, provide an interlock such that the heat source is not activated
unless cooling water is fed to the hearth and coil.
(10) Grounding
Class A grounding (ground resistance of 10
(See the electron beam gun power supply instruction manual.) Connect the
ground terminal of the electron beam gun chamber wall to Class A ground.
Don't operate EB GUN without wiring of a ground cable. For wiring of a
ground cable, read the EB power supply instruction manual carefully.
SECTION 3
CAUTION
DANGER
12
or less) is recommended.