2 electrical isolation, 3 use of residual current protection devices, 4 replacing the two semiconductor fuses – JUMO 709050 IPC IGBT Power Converter IPC 70/100A Operating Manual User Manual

Page 26: Electrical isolation, Use of residual current protection devices, Replacing the two semiconductor fuses, 4 electrical connection

4 Electrical connection

4.1.2 Electrical isolation

The control section, including the inputs and outputs, as well as all operator
controls can be connected to SELV circuits.

The fault signal relay can be connected to SELV or supply potential, without
prejudicing the electrical isolation arrangements of the other inputs and
outputs.

4.1.3 Use of residual current protection devices

The converter is equipped with an internal input rectifier. A short to the housing
can result in a residual DC current that blocks the tripping of the conventional
residual current protection device. For this reason, any RCD used must be an
„all-current sensitive“ version of Type B.
When defining the trip current for the RCD, the leakage currents of the EMC
filter caused by the Y capacitors (<3mA) as well as the capacitive currents
from the cable shielding have to be taken into account.

4.1.4 Replacing the two semiconductor fuses

h Disconnect (all poles) the converter from the voltage supply.
h Wait 1 minute to allow hazardous voltages to discharge.
h Check that no voltage is present on the screw terminals.
h Open the housing as described in Chapter 3.4.1 „Opening the housing“.
h Undo 2 screws of the semiconductor fuse, remove fuses from the holder by

turning laterally, and replace with new fuses.

h Tighten the screws with a maximum tightening torque of 20 Nm.

There is no electrical isolation between the voltage supply of the
power section and the load.

Ensure that the metal housing of the oven or combustion chamber
is properly earthed.

v Chapter 3.2 „Filtering and interference suppression“ Installation

must comply with EVC requirements.