The EC-C1200 inverter has an internal discharge resistor, highlighted in the schematic below. The resistance of the discharge resistor is either 3,9 kOhm or 39 kOhm depending on which inverter variant is selected (small/large system option, see the datasheet for more information).
This discharge resistor is activated automatically to reduce the DC-link voltage when the device is shut off or trips to a hardware fault. It will be disconnected automatically after the inverter is powered up with 24 V auxiliary power and any hardware trips are reset.
Active coolant flow in the inverter cooling circuit is required always when there is voltage on the DC-link and the resistor is activated. If, for example, the inverter's 24 V power is shut off, the cooling circuit must be switched on as long as there is any voltage present on the DC-link.
Note that the discharge resistor cannot force the DC-link voltage to zero if there is some device actively feeding power into the DC-link, since the maximum dissipation power of the discharge resistor is very limited due to the high resistance. The discharge resistor cannot be activated manually by the user, and it cannot be used as a braking resistor.