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12
Resistor braking
Contents of this chapter
The chapter describes how to select the brake resistor and cables, protect the system,
connect the brake resistor and enable resistor braking.
Safety
WARNING!
Do not do work on the brake resistor or the resistor cable when the drive is
energized. A dangerous voltage is present in the resistor circuit, even when the
brake chopper is not operating, or when it is disabled by a parameter.
Operation principle
The brake chopper handles the energy generated by a decelerating motor. The extra
energy increases the DC link voltage. The chopper connects the brake resistor to the
intermediate DC circuit whenever the voltage in the circuit exceeds the limit defined by
the control program. Energy consumption by the resistor losses lowers the voltage until
the resistor can be disconnected.
Selecting the brake resistor
Drives have a built-in brake chopper as standard equipment. The brake resistor is
selected using the table and equations shown in this section.
1. Determine the required maximum braking power
P
Rmax
for the application.
P
Rmax
must be smaller than
P
BRmax
. Refer to
Reference brake resistors (page 175)
2. Calculate resistance
R
with Equation 1.
3. Calculate energy
E
Rpulse
with Equation 2.
Resistor braking 173
Summary of Contents for ACH480
Page 1: ... ABB DRIVES FOR HVAC ACH480 drives Hardware manual ...
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Page 156: ...Frame R1 Frame R1 front side IP20 UL open type 156 Dimension drawings ...
Page 157: ... Frame R1 bottom rear IP20 UL open type Dimension drawings 157 ...
Page 158: ... Frame R1 front side UL Type 1 kit installed 158 Dimension drawings ...
Page 159: ... Frame R1 bottom rear UL Type 1 kit installed Dimension drawings 159 ...
Page 160: ...Frame R2 Frame R2 front side IP20 UL open type 160 Dimension drawings ...
Page 161: ... Frame R2 bottom rear IP20 UL open type Dimension drawings 161 ...
Page 162: ... Frame R2 front side UL Type 1 kit installed 162 Dimension drawings ...
Page 163: ... Frame R2 bottom rear UL Type 1 kit installed Dimension drawings 163 ...
Page 164: ...Frame R3 Frame R3 front side IP20 UL open type 164 Dimension drawings ...
Page 165: ... Frame R3 bottom rear IP20 UL open type Dimension drawings 165 ...
Page 166: ... Frame R3 front side UL Type 1 kit installed 166 Dimension drawings ...
Page 167: ... Frame R3 bottom rear UL Type 1 kit installed Dimension drawings 167 ...
Page 168: ...Frame R4 Frame R4 front side IP20 UL open type 168 Dimension drawings ...
Page 169: ... Frame R4 bottom rear IP20 UL open type Dimension drawings 169 ...
Page 170: ... Frame R4 front side UL Type 1 kit installed 170 Dimension drawings ...
Page 171: ... Frame R4 bottom rear UL Type 1 kit installed Dimension drawings 171 ...
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Page 198: ... Declaration of conformity 198 The Safe torque off function ...
Page 206: ...Dimensions 206 BIO 01 I O extension module ...
Page 212: ...Dimensions 3AXD50000031148 rev A 212 BREL 01 relay output extension module ...