Soft Starting - ESAB Aristo Mig 3001i Service Manual

Soft starting

We recommend soft starting of the machine after replacing control circuit board 20AP1 or
circuit boards or components in the power module. This supplies the power module with a
low DC voltage in order to avoid injury to persons or damage to components.
It is also a good idea to use soft starting when fault tracing in the power module. In addition,
certain measurements in the machine should be made only during soft starting.
The following description refers to the use of soft starting tool SST 2.
Changing wire connections prior to soft starting
1. Disconnect the machine from the mains supply.
2. Disconnect wires 1592 red (+) and 1591 black (-) from circuit board 15AP1.
3. Insulate the wires from each other and from all other parts.
4. Connect soft starting tool SST 2 to 20AP1 and 15AP1 as shown below. Connector C
must only be connected if there is an interuption in the temperature monitoring circuits.
SST 2 connected to 20AP1 and 15AP1
Measurements
The item numbers below refer to the circuit and component position diagrams on pages 52
and 53.
1. Connect the machine to the mains and switch it on.
2. 24 V AC from transformer 2TC1: must be 21 - 27 V
+ 24 VA: must be 24 V $5%.
3.
+ 15 VA: must be 15 V $5%.
4.
5. + 5.1 V, reference voltage for the over-/under voltage and temperature monitoring
circuits: must be 5.1 V $5%.
Set the machine to the MMA mode. The voltage levels given below are depending on the
input voltage from SST 2. If this voltage is higher or lower than in this description, the other
voltages will change correspondingly.
6. Terminals CN09 1 and 2, intermediate voltage from SST 2: 23.4 V.
7. Intermediate voltage after the charge resistors and the short-circuiting thyristor: 23.4 V
8. The voltage across each one of the filter capacitors: 11.7 V. It is important that the
voltage is the same over both of the capacitors.
ca41f2soft
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S0740 800 196/E101019/P76