HEIDENHAIN TNC 370D - Manual (Page 14)

3.7.2 Power Supply
X31 NC Power Supply
Terminal
X31 Assignment
PE Protective ground (YL/GN)
U
1
L1 330 Vac to 450 Vac;
U
2
L2 50 to 60 Hz
–U
Z
Do not use
+U
Z
Do not use
Danger to internal components!
Do not engage or disengage any connections while the unit is under power.
July 02 Mounting and Electrical Installation TNC 370 D 3–11