ESAB Aristo Arc 4000i, Service Manual

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S0740 800 191/E080229/P78
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ct32_15
15AP1 Power board
The power board carries the mains rectifier, the smoothing capacitors, the charging circuit
and the switching circuit.
Circuit board connectors marked NC are not connected.
15AP1:1 Mains rectifier bridge and charging circuit
When the mains power supply is turned on, smoothing capacitors C13--C16
are charged via rectifier bridge BR2. Contactor 2KM1 closes after about twelve
seconds and connects the mains supply to rectifier bridge 15BR1. See
page 43 for a more detailed description of the starting sequence.
Component description:
BR2 Rectifier for charging current.
C1, C2 Capacitors, restricting the inrush charging current to rectifier
bridge BR2. The current while capacitors C13 -- C16 are
charging is about 0.7 A.
C13 -- C16 Smoothing capacitors, with a total capacitance of 1000
m
F.
R5, R10 Discharging resistors for C1 and C2.
R1 Load--limiting resistor (10
Ω
) for the charging current to C13 --
C16.
R8, R9 Potential divider and discharge resistors for C13 -- C16.
R11 -- R13 Varistors. Cut off voltage peaks exceeding about 1000 V.
The varistors do not conduct when the voltage is below 480 V
AC RMS, this corresponds to a peak voltage of 680 V.
R14 Varistor
15BR1 Main rectifier for mains voltage.