
MANUAL MOTOR STARTER GUIDE
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5. Selection criteria
5.1 Sizing manual motor starters for motor applications
Manual motor starters should be sized based on the rated current (for UL full-load amps (FLA)) of the motor. The
rated operational current I
e
of a manual motor starter represents the maximum current rating of the device. Similarly
to thermal overload relays, these devices are provided with a thermal setting range. Manual motor starters should be
selected so that the motor current rating falls between these ranges. If the thermal setting ranges of two devices
overlap for the intended motor current, select the device with a range that will allow greater flexibility for adjust-
ment. For magnetic only (MO) manual motor starters, select the device with a rated operational current Ie equal to,
or the next size above, the FLA of the motor.
5.2 Selected Optimized Coordination (SOC)
As a help to select the right ABB product for the application, the “Selected Optimized Coordination” (SOC) web tool
will be very useful.
In order to guarantee the best performance and the longest lifetime, devices involved in the applications mentioned
above (short-circuit protection devices, contactors, overload relays, soft starters) need to be coordinated.
The coordination between devices cannot be determined directly: tests in power laboratories have to be carried out
to qualify the coordination type at low fault and high fault currents according to IEC or UL standards. ABB coordina-
tion tables are the results of such tests and represent the ABB offerings in terms of motor starting and protection,
selectivity, back-up and switch-disconnector protection.
In the SOC all available ABB coordination tables are stored and easily accessible. The following chapter will guide you
on the main tasks and user interactions.
The SOC is available on
(in the "Support “menu select "Online Product Selection Tools “,
then select “Coordination Tables”) or at the following permanent link:
http://applications.it.abb.com/SOC.
Figure 26: Screenshot from SOC