VANNER
Incorporated
OWNER’S MANUAL
Vanner High Voltage DC-
DC Converter OWNER’S MANUAL
7
Overload Condition
The HBA is current limited to its rated output current (250 or 300 amps). If the 24V load exceeds the
HBA's rated output current, it will continue to provide its rated output current until the battery voltage
falls below 20V. If the battery voltage falls below 20V the HBA will current limit at 90 amps. If the
battery voltage falls below 16V the HBA will shut down.
Output Short Circuit Protection
There are three ways that the output of the HBA is protected from short circuits.
1. The output current increment is monitored and if the rate is above 10A / 100µs, the HBA will
perform a soft shutdown.
2. A comparator will generate an over-current signal if the current in the high voltage side of the
transformer exceeds 70A. The HBA software will detect this signal and the HBA will perform
a soft shutdown.
3. Hardware will detect an over current condition. Once the current in the high voltage side of
the transformer reaches 90A, the HBA will perform a soft shutdown.
The HBA will automatically restart upon removal of the fault condition.
Thermal Protection
The temperatures of critical components within the HBA are continuously monitored. The highest
temperature of these components will be used for temperature control.
During light load conditions (less than 80% of the nominal current rating) the cooling fan will be turned
on at 75°C and turned off at 70°C.
During high load conditions (greater than 80% of the nominal current rating) the cooling fan will be
turned on at 70°C and turned off at 65°C.
The HBA will shut down if any of the following conditions exist:
temperature on the low voltage power stage reaches 82°C, or
* temperature on the high voltage power stage reaches 98°C, or
* temperature on the control board reaches 98°C
The HBA will restart automatically if all of the following conditions exist:
temperature on the low voltage power stage drops below 78°C, and
temperature on the high voltage power stage drops below 92°C, and
temperature on the control board drops below 92°C
The output of the HBA will current limit if the temperature on the high voltage power stage and
control board is below 98°C but above 92 degree C. The output current will be incrementally
reduced to avoid thermal shutdown conditions.
