Emerson Unidrive M700 Installation Manual page 59

4.10.2 External braking resistor
Overload protection
When an external braking resistor is used, it is essential that an overload protection device
is incorporated in the braking resistor circuit; this is described in Figure 4-8 on page 61.
WARNING
When a braking resistor is to be mounted outside the enclosure, ensure that it is mounted in a
ventilated metal housing that will perform the following functions:
• Prevent inadvertent contact with the resistor
• Allow adequate ventilation for the resistor
When compliance with EMC emission standards is required, external connection requires the cable
to be armored or shielded, since it is not fully contained in a metal enclosure. See section
4.12.5 Compliance with generic emission standards on page 70 for further details.
Internal connection does not require the cable to be armored or shielded.
Table 4-7 Minimum resistance values and peak power rating for the braking resistor at 40 °C (104 °F)
Model
200 V
03200050
03200066
03200080
03200106
04200137
04200185
400 V
03400025
03400031
03400045
03400062
03400078
03400100
04400150
04400172
* Resistor tolerance: ±10 %. The minimum resistance specified are for stand-alone drive systems
only. If the drive is to be used as part of a common DC bus system different values may be
required. See Braking resistor software overload protection on page 62.
Unidrive M/HS Frame 3 and 4 Power Installation Guide
Issue Number: 3
Minimum resistance
*
Ω
22
18
74
50
37
Instantaneous power
rating
kW
7.7
9.4
9.2
13.6
18.3
Continuous power
rating
kW
1.5
1.9
2.8
3.6
4.6
6.3
1.5
2.0
2.8
4.6
5.0
6.6
9.0
12.6
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