Resistor braking
91
Resistor braking
What this chapter contains
This chapter describes how to select, protect and wire braking choppers and
resistors. The chapter also contains the technical data.
Braking choppers and resistors with the ACSM1-04
Braking choppers
ACSM1-04 drives have a built-in braking chopper as standard equipment to handle
the energy generated by a decelerating motor.
When the braking chopper is enabled and a resistor connected, the chopper will start
conducting when the DC link voltage of the drive reaches 780 V. The maximum
braking power is achieved at 840 V.
Braking resistor selection
To select a braking resistor:
1. Calculate the maximum power generated by the motor during braking.
2. Calculate the continuous power based on the braking duty cycle.
3. Calculate the braking energy during the duty cycle.
Pre-selected resistors are available from ABB as shown in the table below. If the
listed resistor is not sufficient for the application, a custom resistor can be selected
within the limits imposed by the internal braking chopper of the ACSM1-04. The
following rules apply:
• The resistance of the custom resistor must be at least
R
min
. The braking power
capacity with different resistance values can be calculated from the following
formula
where UDC equals 840 V.
WARNING!
Never use a braking resistor with a resistance below the value specified
for the particular drive type. The drive and the chopper are not able to handle the
overcurrent caused by the low resistance.
• The maximum braking power must not exceed
P
brmax
at any point
• The average braking power must not exceed
P
brcont
P
max
<
U
DC
R
2
Summary of Contents for ACSM1 Series
Page 1: ...ACSM1 Hardware Manual ACSM1 04 Drive Modules 0 75 to 45 kW...
Page 2: ......
Page 4: ......
Page 14: ...Table of contents 14...
Page 20: ...About this manual 20...
Page 24: ...The ACSM1 04 24...
Page 30: ...Planning the cabinet assembly 30...
Page 46: ...Planning the electrical installation 46...
Page 70: ...Maintenance 70...
Page 84: ...Technical data 84...
Page 90: ...Mains filters 90...
Page 96: ...Dimension drawings 96 Frame size A...
Page 97: ...Dimension drawings 97...
Page 98: ...Dimension drawings 98 Frame size B...
Page 99: ...Dimension drawings 99...
Page 100: ...Dimension drawings 100 Frame size C air cooled module...
Page 101: ...Dimension drawings 101...
Page 102: ...Dimension drawings 102 Frame size C for cold plate mounting...
Page 103: ...Dimension drawings 103 Frame size D air cooled module...
Page 104: ...Dimension drawings 104 Frame size D for cold plate mounting...
Page 106: ...Dimension drawings 106 Mains filters type JFI xx...
Page 108: ...Dimension drawings 108 Braking resistors type JBR xx...
Page 110: ...Dimension drawings 110...
Page 111: ......