Main Circuit Diagram; Forced Cooling Components; Control Side Devices; Overheat Protection Ptcs (Rg101, Rt101, Rg201) - Kemppi FASTMIG X 450 Service Manual

1. MAIN CIRCUIT DIAGRAM

1.1. Forced cooling components

Auxiliary transformer (T002)
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Cooling fans (M001, M002).
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Primary choke (L001)
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Auxiliary rectifier bridge (G003)
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Secondary rectifier card (Z003)
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Secondary cut-off card (Z004)
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Secondary cut-off shunt resistor (R004)
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Secondary choke (L002)
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Blocking diode (V7)
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Main transformer (T001)
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The auxiliary transformer (T002) is a toroidal transformer. It has 400 V primary and 38V and 20V secondaries. 38V secondary
voltage is rectified with auxiliary rectifier (G003) to 50V dc -voltage. 50V dc voltage supplies the serial communication bus and
devices that are connected to it. 20V secondary supplies the control card A001 circuitry and the fans M001 and M002.
The primary choke (L001) limits the inrush current to the DC-link capacitors when the mains switch is turned on. It also increas-
es a power factor. Secondary cards rectifies secondary voltage and with cut-off resistor forms some special welding characteris-
tics as PipeRoot. The secondary choke (L002) reduces the ripple contents of secondary current. To achieve better welding prop-
erties L002 is constructed so that choke saturates in certain voltage and current values. Blocking diode V7 prevents dc-link volt-
age from rising too high while turning on device. The main transformer (T001) has one primary winding (7 turns) and two serial
secondary windings (1+1 turns).

1.2. Control side devices

Mains switch (S001)
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Varistors (R001)
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EMI-choke (L003)
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DC-link card (Z002)
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System bus fuse (F001)
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Main circuit card (Z001)
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Secondary shunt resistor (R002)
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Gate driver card (A001)
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Processor card (A002)
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System card A003
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Mains switch (S001) disconnects power source from the mains and the varistors (R001) protect power source from the low
energy voltage spikes. Choke (L003) reduces conducted electromagnetic interference (EMI) to the supplying power network.
DC-link card (Z002) has only dc-link capacitors and discharging resistors. Z002 is connected to main circuit card Z001 by conduc-
tive screwtowers. System bus fuse (F001) protects system bus power feed (+50Vdc) against short circuit on system bus. Size of
the fuse is 6.3A. Secondary current is measured with the shunt resistor (R002). Control of the device is made by all three con-
trol cards (A001, A002 and A003).

1.3. Overheat protection PTCs (Rg101, Rt101, Rg201)

PTC resistors connected to the primary heat-sinking profile (Rg101), main transformer (Rt101) and secondary heat-
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sinking profile (Rg201) provides overheat protection for the power source.
Kemppi OY
SERVICE MANUAL
FASTMIG X
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