ABB ACSM1 System Manual page 32

32
•
Nominal DC voltage: Average DC voltage level, when 400VAC supply
connected to ACSM1 AC input terminals.
•
DC voltage range: Actual DC voltage level with 3-phase AC supply
voltage range (380...480VAC +10% / -15%). Actual DC voltage with the
nominal load can be defined based on 3-phase AC supply voltage with
following formulas.
•
Charging limit: Charging relay will be closed, when this DC voltage level
has been reached. There are also other criteria (du/dt, time delay) in
firmware for closing the charging relay. Charging relay is opened, if the
DC link voltage is below 75% of the U
•
DC voltage control: The over voltage and under voltage control of DC link
voltage level are enabled as default. Then ACSM1 drive modules will
limit motoring and generating torque, if needed to keep DC link voltage
within control limits. In common DC configurations with enabled braking
chopper the over voltage control mode should be disabled. Please see
voltage control parameters in group 47.
•
DC over voltage and under voltage trip limit: These limits values protect
ACSM1 drive modules. Drive module will trip and give fault message, if
the DC link voltage will reach these levels.
•
Braking chopper limits: The braking chopper in ACSM1 drive module will
be activated (if braking chopper is enabled), when the DC link voltage will
reach the low level (U
level (U
with continuous current and the maximum braking power level is
reached.
Average DC voltage:
dc,brcl
), then the braking chopper is feeding the braking resistor
dc,brch
≈ 35 ×
U . 1 U
dc , ave ac
, when the drive is not running.
dc
). If the DC link voltage level will reach the high