Mounting Components On The Heat Sink - ESAB Caddyt Arc 150i Service Manual

Mounting components on the heat sink

Thermal paste
Apply thermal conducting paste to the components before fitting them to the heat sink.
Start by cleaning the heat sink, and then apply a very thin, even layer of thermal paste to
the contact surfaces of the components. The purpose of the paste is to fill out any hollows
in the surfaces of the components and the heat sink. Those parts of the component and the
heat sink that are in true metallic contact may already have good thermal contact.
Mount the components as described below.
See the spare parts list for the order number for thermal paste. Use only the paste
recommended by us.
Fitting instructions
15AP1 Power board with semiconductor module
1. Clean the heat sink and apply thermal conducting paste to the
semiconductor module as described above.
2. Fit the board and tighten the screws to a torque of 2.5 Nm, and then further
tighten them to 4.5 Nm.
3. Tighten the screws that connect transformer 15TM1 and capacitor 15C1 to
circuit board 15AP1 to a torque of 4.5 Nm.
Warning: Incorrectly fitted components can cause failure. Do not tighten the
screws to more than 4.5 Nm.
Note: If capacitor 15C1 or transformer 15TM1 have to be replaced, the power
board must be removed and then refitted as described above.
15D1 Diode module
1. Clean the heat sink and apply thermal conducting paste to the diode
module as described above.
2. Fit the module and tighten the screws to a torque of 2.5 Nm, and then
further tighten them to 4.5 Nm.
3. Tighten the connections to circuit board 15AP2 to 4.5 Nm.
4. Tighten the screws that connect transformer 15TM1 and inductor 15L1 to
circuit board 15AP2 to a torque of 4.5 Nm.
15ST2 Thermal overload switch
1. Clean the heat sink and apply thermal conducting paste to the thermal
overload switch as described above.
2. Fit the thermal overload switch and tighten the screw to 2 Nm.
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S0740 800 161/E061205/P66