Altitude of installation.
The MEsoftstart range of soft starters are designed and tested at 1400m above sea level. When planning to use the soft starter
at altitudes higher than 1400m the soft starter the guideline is to de-rate at 0.67% per 100m for higher altitudes.
1. The application is a fan in a 400V AC3 distribution, which does not require high starting torque. A normal 3-wire
configuration (with bypass) 90kW fan motor is specified, with normal duty starting: Ramp-start of 20s duration,
requiring no more than 200% of the motor's running current during start-up:
Normal full-load current
Starting current needed
b) Conclusion: our starting current < 480A allowed for normal duty with MEsoftstart/I01
2. The application is a compressor or conveyor in a 400V AC3 distribution, requiring high starting torque. The same
90kW motor – this time driving a compressor motor – is specified (with bypass), with heavy duty starting: slow
ramp longer than 30s duration and approximately 400% of the motor's running current during start-up:
Here, starting current needed
b) Conclusion: our starting current >250A allowed for heavy duty with MEsoftstart/I01. Looking at
MEsoftstart/I02, its heavy duty starting current of 390A is also too low, i.e. MEsoftstart/I03 with a heavy
duty starting current of 900A would suffice.
Checking the Product when unpacking
Unpack the product and check the label on the soft starter to ensure that the model agrees with the order and that the product
is intact. Figure 2 shows product labels for the MEsoftstart/I01 and MEsoftstart/I02 models. From the label can be seen the
rated continuous current of the MEsoftstart soft starter, as well as the maximum starting current for normal duty. The rated
supply voltage is also visible on the label.
Note that the labels in Figure 2 are both labels for MEsoftstart models without built-in bypass contactors. This can be seen
from the grid side and motor side bypass terminal markings on the label.
Recommended motor sizes are shown on the label. These motor sizes are applicable for normal 3-wire installation. Also refer
to the tables in paragraph 1.1.1 for more information about the supported motor sizes.
= P(kW) / (√3 × PF × VL-L) × 1000
= 90 / (√3 × 0.8 × 400) × 1000
= 200% × 162.4
Use soft starter (MEsoftstart/I01).
= 400% × 162.4
Use soft starter (MEsoftstart/I03).