Integrated precharge
Precharge: The BAT+ relay is bridged with a 2 Ω resistance. This produces current ow charging the
capacitors in the connected consumers, e.g. an inverter. When current ow undershoots the preset
maximum at the end of the precharge phase, the BAT+ relay closes and precharging ends.
Default parameters
■
Precharge time: 0.65 s
■
Current at end of precharge time: < 2 A
These parameters may be changed without notice during series production or be changed to match
customer requirements.
DAMAGE
■
The lower the current at the end of the precharge time, the lower also the wear on the relay contacts.
■
No more than 10 precharge operations may be performed or attempted within 10 minutes.
Two factors affect residual current at the end of the precharge time:
1. The connected capacity value. Experience has shown that the precharge facility’s design can handle
the reasonably expectable capacities.
2. Continuous current I
DC
at the end of the precharge time.
Typical causes for I
DC
■
Consumers that are already attempting to supply power during precharging, e.g. DC/DC converters. In
this case, DS/DC converter power-up needs to be delayed so that it does not supply power until after
precharging has nished (e.g. via ‘enable pin’).
■
Consumers with significant input capacities feature bleeder resistors (discharge resistors) that ensure
input capacities are discharged when switched off. Their resistances are typically within the low kΩ
range. Parallel circuits with multiple consumers will often result in significantly higher I
DC
.
Contact data
Headquarters
HAWE Hydraulik SE
Einsteinring 17
85605 Aschheim
Germany
Email: [email protected]
www.hawe.com
Phone: +49 (0) 89 / 37 91 00 - 1000
Manufacturer
HAWE Mattro GmbH
Pocherweg 24
6130 Schwaz
Austria
e-mail: [email protected]
www.hawe.com
Phone: +43 (0) 5242 / 20904 - 0
38/39
B 6130 - 02-2022 - 1.0en
HAWE Hydraulik SE
