Emerson Unidrive M700 Installation Manual page 58

High temperatures
Braking resistors can reach high temperatures. Locate braking resistors so that damage
cannot result. Use cable having insulation capable of withstanding high temperatures.
WARNING
4.10.1 Heatsink mounted braking resistor
A resistor has been especially designed to be mounted within the heatsink of the drive (size 3 and 4).
See section 3.10 Size 3 and 4 internal braking resistor for mounting details. The design of the
resistor is such that no thermal protection circuit is required, as the device will fail safely under fault
conditions. On size 3 and 4 the in built software overload protection is set-up at default for the
designated heatsink mounted resistor. The heatsink mounted resistor is not supplied with the drive
and can be purchased separately.
Table 4-6 provides the resistor data for each drive rating.
The internal / heatsink mounted resistor is suitable for applications with a low level of
NOTE
regen energy only. See Table 4-6.
Braking resistor overload protection parameter settings
Failure to observe the following information may damage the resistor.
The drive software contains an overload protection function for a braking resistor. On
size 3 and 4 this function is enabled at default to protect the heatsink mounted resistor.
CAUT ION
Below are the parameter settings.
Braking resistor rated power
Braking resistor thermal time constant
Braking resistor resistance
For more information on the braking resistor software overload protection, see
Pr 10.030, Pr 10.031 and Pr 10.061 full descriptions in section 4.10.3 Braking resistor
software overload protection on page 62.
If the resistor is to be used at more than half of its average power rating, the drive
cooling fan must be set to full speed by setting Pr 06.045 to 11.
Table 4-6 Heatsink mounted braking resistor data
Part number
DC resistance at 25 °C
Peak instantaneous power over 1 ms at nominal resistance
Average power over 60 s *
Ingress Protection (IP) rating
Maximum altitude
* To keep the temperature of the resistor below 70 °C (158 °F) in a 30 °C (86 °F) ambient, the
average power rating is 50 W for size 3, 100 W for size 4. The above parameter settings ensure this
is the case.
58
Parameter
Parameter
Unidrive M/HS Frame 3 and 4 Power Installation Guide
Size 3
200 V
drive
Pr 10.030
50 W
Pr 10.031
3.3 s
Pr 10.061
75 Ω
Size 3
1220-2752
75 Ω
8 kW
50 W
Size 4
400 V 200 V 400 V
drive drive drive
100 W
2.0 s
38 Ω
Size 4
1299-0003
37.5 Ω
16 kW
100 W
IP54
2000 m
Issue Number: 3