Anti-Dew Startup Sequence - ABB PCS6000 User Manual

8.5. Anti-dew startup sequence

The PCS6000 converter can be operated at very cold temperatures. The medium voltage
power part of the converter can work, if the following conditions are fulfilled:
Start and operating criteria for the power part:
1) The cooling water temperature is > 0°C (water/glycol mixture).
2) The internal converter air temperature is > 5°C.
3) The "anti-dew" monitoring is released (No condensation/dew).
Typical, these conditions are always fulfilled, when the converter is in production mode and
the internal losses heat up the converter. If the converter does not work in production mode
and is in the OFF-state, an "Auto-Maintenance-Mode" is running as long as the auxiliary
voltage is available. This mode turns on the WCU pump automatically. The WCU pump
circulates the water internally in the converter. The losses of the pump go almost 100% into
the water and the water heats up the converter inside. The 3 start conditions are always
fulfilled. The converter can immediately go in to production mode.
If the auxiliary voltage was switched off for a long time (eg, before commissioning or
service) and the converter was cooled down to low temperatures, the converter cannot be
started immediately and go into production mode. After turn on the auxiliary voltage it has
to run an anti-dew startup sequence, which raises the temperature until the start
conditions are reached. The flow chart is show in Fig. 8–2.
The first phase in the start-up sequence is to turn on the space heater in the CCU.
The second phase is to turn on WCU pump. The WCU pump circulates the water internally in
the converter. The losses of the pump go almost 100% into the water and the water heats
up the converter inside
The anti-dew startup sequence will prevent dew situations and the risk of damaged
components.
IMPORTANT! At very low temperatures (eg, -10 °C) the complete anti-dew startup
sequence can take up to 12 hours.
PRODUCT
PCS6000
DOCUMENT KIND
User manual
DOCUMENT ID.
3BHS600000 E40
OPERATION
REV. LANG. PAGE
G en 99/114