Description Of Operation - Kemppi Master S 400 Service Manual

Service manual Master S 400 and 500

3.5. Description of operation

Master S is divided in to six functional parts
Z001 main circuit card with control circuitry

Over voltage protection

IGBT based power section with full bridge architecture. Switching frequency is dual mode: 50kHz
in low and 20kHz in higher output power. Module has NTC resistor for overheat protection. It
limits the primary heat sink temperature up to 90 degrees of Celsius.

IGBT driver circuit

Input rectifier

Auxiliary power supply (switching mode)

PSU for secondary power (Remote controller)

DC-link capacitors (2x60μF film capacitors)

Control card functions

OCV (open circuit voltage) adjustment circuit keeps the voltage stable and at a safe level.

Microcontroller (note that it cannot be updated in the field. Connector is in the primary side)
Z002 secondary rectifier card

Secondary voltage rectification
P001 Panel card

7-segent displays

Display selection button for voltage/current

Setup functions

Potentiometer for current set value adjustment
T001 Main transformer

Lowers the voltage to lower level

Isolates primary and secondary
T002 Auxiliary transformer

needed for antifreeze and TIG functions
Cellu coil (optional)

Increasing voltage for cellulosic electrodes
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Kemppi Oy
Version 1.1 5.9.2014