Huaao NBC series, Operation Manual, Page: 15 / 18

(1) Heating Power Supply Outlet (AC36V)
The outlet connects the heater coil of the CO
2
regulator.
(2) Fans
The fans cool down the heating components inside the welding machine.
Note: The fans do not work immediately after the welding machine is powered on. Instead, they
start working when you start welding, and stop working 15 minutes after you stop welding.
(3) Power Supply Input Cable
The machine must be fitted with a reliable grounding using the floral wire. The other three wires
connect the three-phase 380V/50Hz power supply. The following table shows the cable
specifications.
Model NBC-350III NBC-500III NBC-630III
Input power 3-Phase AC380V 3-Phase AC380V 3-Phase AC380V
Cable Input side
≥ 2.5 mm 2 ≥ 6 mm 2 ≥ 10 mm 2
Output side 35 mm
2
70 mm
2
95 mm
2
Ground cable
≥ 2.5 mm 2 ≥ 6 mm 2 ≥ 10 mm 2
(4) Ground Bolt
To ensure personal safety and normal operating condition, the ground wire (floral) in the input
cable must be grounded in a reliable manner, or the bolt must be grounded using the ground cable
specified in the table above.
(5) Automatic Air Switch
This switch is automatically powered off when the welding machine is overloaded or faulty, so as
to ensure personal safety and protect major components. Generally, this switch is turned on by
being pushed upwards. Do not use this switch to power on or off the welding machine; instead,
use the power supply switch on the power distribution board (cabinet).