Description Of Operation; Z001 Main Circuit Card - Kemppi MinarcTig Evo 200 Service Manual

Service manual MinarcTig Evo 200

3.4. Description of operation

MinarcTig Evo has the following parts and components:

Main circuit card Z001

Control card A001

Spark card A002

Panel card P001

Main switch S001

EMC choke L001

Auxiliary transformer T002

Spark transformer T003

Cooling fan M001

Shunt R001

Gas valve Y001

TIG torch control connector X001

Remote control connector X002

Main output terminals (Dix connectors) X003 and X004

TIG torch connector X005

Cooling fan is in the back of the machine and fresh air intake is through the rear grill. Air flows through the
heat sinks and exits in the front of the machine.
Note that both Z001 and A001 cards have +24VDC, but they are in different potential, Z001 in primary
and A001 in secondary.

3.4.1. Z001 Main circuit card

Main circuit card coil components and their functions:

Main transformers transformer ratio is 3,67:1; its primary winding is 11 turns (wire)
and secondary 3 (foil). The transformer has a 160°C PTC for over heat protection.
While temperature rises the resistance stays under 100Ω until the breakdown point,
then the PTC goes to high-resistance mode (>10kΩ). Control logic stops the inverter
if the resistance value rises over 1,5kΩ.

Secondary choke L4 inductance is 5μH and its winding has 10 turns. The choke
slows the secondary voltage changes and works as energy storage in the deep short
circuits.

PFC choke works together with PFC circuit. It has 66 turns.
Main circuit card itself provides the following functions:

DC-link soft start charging and over voltage disconnecting circuit. It avoids full power
connection if primary has short circuit or main supply voltage rises over the safety
limit. Relay control is in A001 card.

EMC filtering circuit filters EMC disturbances from main supply voltage to the ma-
chine and vice versa.

The single-phase rectifier/PFC module rectifies the mains voltage (nominal 230VAC)
to PFC circuit, approx nominal value of 320VDC. Rectifier holds four power diodes.
PFC circuit is integrated in the same module with rectifier diodes. PFC circuit (IGBT,
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Kemppi Oy
Version 1.1.5. 29.9.2015