A001 Control Card - Kemppi Minarc Evo 150 Service Manual

Service manual Minarc Evo 150 and 180

Both modules have integrated NTC resistors for over heat protection: In 0-40° C
environment temperature range, resistance varies between the 60-15kΩ if the
machine is cool. In the overheat situation NTC resistance lowers down to 2kΩ and
even lower. Machine stops the inverter in the 2kΩ point. Note that NTC has
descending nominal curve: When temperature rises resistance lowers.

Z001 card has an auxiliary power supply which delivers auxiliary voltages to Z001
and A001 cards. Primary side: +16VDC for the upper IGBT gate buffer, floating
+16VDC and floating GND for the lower IGBT gate buffer, and +24VDC for the
cooling fan and charging relay. Secondary side: +12VDC (tolerance ±1V) for the
remote controller and reference GND.
o
Note! Voltages are in the primary side (except +12VDC) so be careful while
measuring the voltages.

DC-link with two 470μF electrolytic capacitors. Machine current is measured in the
DC-link and feedback goes to the A001 card. DC-link is discharged by cooling fan
while main switch is turned off.

Secondary rectifier has two working and three demagnetizing diode cases. Each
case holds two diodes so total quantity is doubled.

OCV (open circuit voltage) adjustment circuit keeps the voltage stable and at a safe
level.

Secondary shunt resistor is only for measuring the secondary current for the
displays. Machine uses primary current measuring for inverter feedback.

Remote control connection circuit with galvanic isolation. Remote controller reading
is in the A001 card.

Cooling fan control circuit. Control signal comes from the A001 card.

Dual forward inverter gate driver circuit. Control signal comes from the A001 card.

Secondary voltage monitoring in VRD mode. Limit is 32VDC and if voltage is higher
VDR led is off in A001 card.

3.4.2. A001 Control card


Minarc Evo 150 and 180 are using same control card but software is different so also
spare part codes are different. Cards are not programmable in field.

Microcontroller controls e.g. current and voltage measuring and adjustment,
protection circuits, remote control function, panel button function, panel LEDs,
provides serial bus and saves calibration data.
o
Note that calibration and service connection is in the primary side without
galvanic isolation. This is meant only for production use

Control card has control buttons for remote control ON/OFF and TIG/MMA selection.
It has analogue potentiometer for welding current set value. These buttons and
potentiometer are used for the machine calibration also.

Card LEDs have following functions: Machine ON, TIG/MMA selected, overheat
protection ON and VRD activated. VRD LED lights only when it is activated, so in TIG
mode and during the welding in MMA mode it is off.

7-segment display shows the current set value while not welding. During the welding
it shows actual welding current value. In calibration mode is shows the measured
current value of machine.
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Kemppi Oy
Version 1.3 30.9.2015