15Ap1 Power Board; 15Ap1:1 Mains Rectifier Bridge And Charging Circuit - ESAB Arc 4000i Service Manual

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
C1, C2
C13 -- C16 Smoothing capacitors, with a total capacitance of 1000 mF.
R5, R10
R1
R8, R9
R11 -- R13 Varistors. Cut off voltage peaks exceeding about 1000 V.
R14
15BR1
ct32_15
Rectifier for charging current.
Capacitors, restricting the inrush charging current to rectifier
bridge BR2. The current while capacitors C13 -- C16 are
charging is about 0.7 A.
Discharging resistors for C1 and C2.
Load--limiting resistor (10 Ω) for the charging current to C13 --
C16.
Potential divider and discharge resistors for C13 -- C16.
The varistors do not conduct when the voltage is below 480 V
AC RMS, this corresponds to a peak voltage of 680 V.
Varistor
Main rectifier for mains voltage.
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S0740 800 191/E080229/P78