Braking; Braking Unit (Internal) - gefran installationSIEIDrive ADL300 Quick Start Up Manual, Specification And Installation

7.8 Braking

There are various possible types of braking:
- Internal Braking Unit
- Injection of direct current from the Inverter into the motor (D.C. braking)
There are two essential differences between the two braking methods:
- A braking unit can be used for speed reduction (e.g.: from 1000 to 800 rpm), whereas D.C. braking can only be
usedfor braking to standstill.
- The energy in the drive is converted into heat in both cases. This conversion takes place in a braking resistor
encased in the braking unit. With D.C. braking, the energy is converted into heat in the motor itself, resulting in a
further rise in motor temperature.

7.8.1 Braking unit (internal)

Frequency-regulated asynchronous motors during hyper-synchronous or regenerative functioning behave as genera-
tors, recovering energy that flows through the inverter bridge, in the intermediate circuit as continuous current.
This leads to an increase in the intermediate circuit voltage.
Braking units (BU) are therefore used in order to prevent the DC voltage rising to an impermissible value. When used,
these activate a braking resistor that is connected in parallel to the capacitors of the intermediate circuit. The feedback
energy is converted to heat via the braking resistor (R
four-quadrant operation.
In the standard configuration, ADL drives (≤ 55kW) comprise an internal braking unit.
Note!
When the internal braking unit is present the protection must consist of fast-acting fuses! Follow the relative assembly instructions.
A twisted cable must be used for the connection of the braking resistor (terminals BR and C or BR1 and BR2). If the
resistor includes a thermal protection device (Klixon), this must be connected to the "External fault" input of the drive.
Size
1040
1055
2075
2110
3150
3185
3220
4300
4370
4450
5550
5750
2055
3075
3110
4150
4185
4220
5300
5370
64
_
R
BR
U
ZK
BU
Figure 7.8.1: Operation with braking unit (circuit diagram)
Table 7.8.1: Technical data of the internal braking unit
I
rms
(A)
5.5
8.5
8.5
15.5
22
37
37
57
57
76
76
15.5
22
37
57
57
76
76
ADL300 • Quick installation guide - Specifications and connection
), thus providing very short deceleration times and restricted
br
M
3
I
pk
(A)
ADL300-...-4, 3ph
7.8
12
12
22
31
52
52
80
80
107
107
External Braking Unit (optional)
ADL300-...-2T, 3ph
22
31
52
80
80
107
107
External Braking Unit (optional)
E
R
br
(Ω)
100
67
67
36
26
15
15
10
10
7.5
7.5
36
26
15
10.1
10.1
7.5
7.5