Operation Manual

Protect PV.250 Operating Instructions
Page 15 of 51 80000027023 BAL, en
As soon as the control assembly of the Protect PV.250 is supplied
with voltage, fan control always starts with the fast fan stage. The
control can be restarted to check whether the fans are working cor-
rectly. For example, after maintenance work, it is not necessary to
wait for the fans to reach the temperature criterion to switch on the
fast fan stage.
The fast fan stage is always active for at least a certain time. The
IGBT stack temperature is checked after this time. If it is below a
certain value, fan control switches to the slow fan stage.
The IGBT stack temperature is also checked in the slow fan stage.
If it is below a certain value, the fans are switched off. However, if
the temperature rises again during operation with the lower fan
stage, fan control switches back to the fast fan stage.
If the IGBT stack temperature rises above a certain value with the
fans switched off, fan control switches to the fast fan stage.
Slow fan stage
Fan switched off
IGBT-Sack temperature
< limit
Start
Fast fan stage
least time
IGBT-Stack temperature
< limit
IGBT-Stack temperature
> limit
IGBT-Stack temperature
> limit
Fig. 6 Fan control