
MANUAL MOTOR STARTER GUIDE
APRIL 19
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3. Load types
Although the name suggests that their suitable application is limited only to motors, manual motor starters can ad-
ditionally be used for controlling and protecting other types of loads, such as heaters. When combined with an
additional controller, the applications for manual motor starters are even broader. The table below shows the tested
ratings for ABB manual motor starters and AF contactors.
Tested ratings for manual motor starters
Tested ratings for contactors < 100 Amps
—
AC-1: General use
—
AC Motors
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AC-3: Squirrel-cage motors: starting, switches off mo-
tors during running time
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AC-4: Squirrel-cage motors: starting, plugging, inching
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DC-1: Non-inductive or slightly inductive loads, re-
sistance furnaces, heaters
—
DC-3: Shunt-motors, starting, plugging (1), inching (2),
dynamic braking of motors
—
DC-5: Series-motors, starting, plugging (1), inching (2),
dynamic braking of motors
—
AC-1: General use
—
AC Resistance Air Heating (100,000 electrical
cycles)
—
AC Motors
—
Elevator control, AC Motors (500,000 electrical
cycles)
—
AC-5a: Electric discharge lamps (ballast)
—
AC-5b: Incandescent lamps (tungsten)
—
AC-8a: Hermetic refrigerant compressors
—
DC-1: General use
—
DC Motors
Table 10: Load types
3.1 General use and heaters
The harmonized utilization category AC-1 covers general and resistive type loads. This includes non-inductive or
slightly inductive loads, as well as resistance furnaces and heaters. Additional ratings, such as “Resistance Air Heat-
ing” and “CSA Electrical Heating Control”, which require additional electrical cycling, can be performed to further
validate control devices for use in heating applications. However, the general use AC-1 rating is sufficient for most
heating applications.
ABB manual motor starters are suitable for manual control and the protection of heating loads. Magnetic only (MO)
types can be selected when additional overload protection is not required.