Nelson ALPHA 850 - 6 Equipment fuses; 6.1 Fuse elements

6 Equipment fuses Page 31
Stud welding unit operating manual Date: July 2021
ALPHA 850 07.2021 / EN Rev.: A
6 Equipment fuses
6.1 F
use elements
For protection against impermissibly high current values, there are four fuses inside
the welding device for fuse protection of the control current circuits below.
The power unit is secured with the 35 A network fuse.
Warning:
• Only authorized electro-technical personnel are allowed to open the
welding device or work inside its housing.
• Before opening the welding device, the ALPHA 850 must be switched
off, unplugged and secured against restart!
• Before closing the device housing, the earth conductors must be
reconnected to all housing parts.
• Nominal values for fuse elements
Backup Nominal current Nominal voltage Response behaviour
F1 1 A 250 V Slow
F2 4 A 250 V Slow
F3 4 A 250 V Slow
F4 0.315 mA 250 V Slow
• Secured control current circuit
Backup Fuse protection
F1
Supply to 18 VAC PCB
F2
Supply to 18 VAC start monitor/coil monitor
F3 Coil current circuit of connected welding gun
F4 fan