Technical information
and start-up
BSC624-12V-B
14
3.4.3
Overload protection – derating
This safety installation is a self-protection feature of the DC/DC converter. If the device reaches a defined
temperature threshold, this reduces the power rating (derating) to protect the device from damage caused by
overheating. Consequently, the maximum possible current is reduced proportionally to the temperature increase in
order to avoid a further rise in the temperature.
Via the CAN interface, the currently transferable current
LVCUR_AVL
is reported back. Here, it can be identified
whether or not the device is in the derating mode.
A total of 8 temperature sensors are installed to measure the temperature. These sensors are divided into 4
measuring groups:
Installation position / measuring point
Number of temp. sensors
Active regulation max. current
Switches buck / boost converter
2
no
Switches HV side transformer stage
2
yes
Switches LV side transformer stage
2
yes
Winding HF power transformer 1 + 2
1 each
yes
Switches buck / boost converter
Since very low losses occur at the switches of the buck / boost converter and an extremely efficient cooling
predominates, these measuring values only show slightly increased values regarding the cooling liquid
temperature. For this reason, these measuring values provide information on the actual ambient temperature in the
device. Generally, the device shuts down when the temperature of the switches of the buck / boost converter is
>/= 81°C. If this temperature falls to </= 80°C, the device is 100% operable again. Here, no derating occurs but a
direct shut-down of the device. With a shut-down of the device, the signal
E_OVERTEMP
is emitted.
