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4. Select the resistor so that the following conditions are met:
•
The rated power of the resistor must be greater than or equal to
P
Rmax
.
•
Resistance
R
must be between
R
min
and
R
max
given in the table for the used
drive type.
•
The resistor must be able to dissipate energy
E
Rpulse
during the braking cycle
T
.
Equations for selecting the resistor:
t
on
P
Rmax
P
Rave
T
For conversion, use 1 hp = 746 W.
Equation 1
When the drive supply voltage is 200 … 240 V:
When the drive supply voltage is 380 … 415 V:
When the drive supply voltage is 415 … 480 V:
Equation 2
Equation 3
R
Calculated brake resistor value (ohm). Make sure that:
R
min
<
R
<
R
max
P
Rmax
Maximum power during the braking cycle (W)
P
Rave
Average power during the braking cycle (W)
E
Rpulse
Energy conducted into the resistor during a single braking pulse (J)
t
on
Braking time (one cycle) (s)
T
Braking cycle time (s)
WARNING!
Do not use a brake resistor with a resistance below the minimum value specified
for the particular drive. The drive and the internal chopper are not able to handle
the overcurrent caused by the low resistance.
174 Resistor braking
Summary of Contents for ACH480
Page 1: ... ABB DRIVES FOR HVAC ACH480 drives Hardware manual ...
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Page 114: ...114 ...
Page 122: ...122 ...
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 ...
Page 172: ...172 ...
Page 180: ...180 ...
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 ...