ABB ACS880-87LC-4000A/4021A-7, Hardware Manual

Page: 139 / 144

Cooling and heating 139
Heating
The converter is not equipped with a heating element. Thus, it must be heated using the
coolant circuit. The external liquid cooling unit must be equipped with a heater capable of
heating the converter up within reasonable time. Temperatures in each converter cubicle
are monitored separately by using thermostats with a fixed set point of 10 ± 5 °C. There is
no specific heating request signal in the converter cabinet for the customer. You can check
the heating request signal on the terminal XDI:7 on the BCU control unit of the grid-side
converter. For more information, see
Hardware manual and the circuit diagrams delivered
with the converter .
Note: The cooling unit must always be equipped with a proper overtemperature protection
device(s).
The operation of the converter temperature control logic is described in the following
sections in two different circumstances: cold start and normal start.

Cold start (-30 °C … +10 °C)
The auxiliary 230 V AC and 400 V AC power is connected to terminal block X1 on the
converter. At first, the auxiliary power is not switched on and the printed circuit boards are
not energized.
1. Switch on the external cooling unit and heating of the cooling liquid. Make sure that
the coolant circulates in the converter cooling circuit (all cubicles).
2. Switch on the auxiliary voltages. Connect input voltage to the terminal X1:
230 V AC (UPS) and 400V AC (non-UPS).
3. Wait for the converter cabinet to warm up.
4. If the temperature of the auxiliary control cubicle is < -10 °C, the fans inside the
converter cabinet start and speed up the warming process.
5. Wait until the fans stop. The temperature has risen enough in all parts of the converter
cabinet.
6. When the temperature is high enough and the fans stop, a control relay switches on
the energizes the control boards automatically. The converter is ready for the normal
power up.
Temperature sensors control relays K12.1, K18.1, K18.2 and K18.3. When the converter
is heated up properly (
T > 10 °C), auxiliary power to the printed circuit boards is switched
on by relay K18.3. The relay stays energized unless auxiliary power is switched off with
circuit breaker [F11]. The heating requests to the cooling unit change automatically from
on to off when heating is not needed any more and vice versa. The converter also
switches off the cooling pump start request if the converter is not powered up yet (does not
need any cooling).

Normal start (-30 °C … +10 °C)
When the temperature in all converter cubicles is above 10 °C, no heating is needed. You
can start without any pre-heating:
1. Switch on the external liquid cooling unit and the pump that circulates coolant in the
converter.
2. Switch on the auxiliary power. The converter is ready for the power up.