CG emotron TSA Series, Instruction Manual

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36 Application guidelines CG Drives & Automation 01-5980-01r2
4.4 Special conditions
4.4.1 Small motor or low load
The minimum load current for the Emotron TSA softstarter
is 10% of the rated current for the softstarter. An exception
is the TSA52-016 for which the minimum load current is
2 A.
Example: TSA52-056 with rated current of 56 A has a
minimum current of 5.6 A.
Please note that this is “minimum load current” and not
minimum rated motor current.
Note also that motor current can not be set below
25% of rated current for the Emotron TSA.
4.4.2 Ambient temperature below
0°C (32°F)
For ambient temperatures below 0 °C (32 °F) an electric
heater or similar must be installed in the cabinet. The
softstarter can be mounted remotely from the motor since
the distance between the motor and the softstarter is not
critical.
4.4.3 Pump control with softstarter
and AC drive together
It is possible, e.g. in a pump station with two or more
pumps, to use one Emotron FDU AC drive on one pump
and softstarters on each of the other pumps. The flow of the
pumps is then controlled by the pump control function in
the Emotron FDU.
4.4.4 Starting with counter-
clockwise (reverse) rotating
loads
It is possible to start a motor clockwise (forward direction),
even if the load and motor are rotating counterclockwise
(reverse direction), e.g. fans.
Depending on the speed and the load “in the wrong
direction”, note that the current can be quite high.
If required, it is possible to limit the start currents by
increasing the start time (menu [336]).
4.4.5 Running motors connected in
parallel
When starting and running motors connected in parallel,
the total amount of the motor current must be equal or
lower than the rating of the connected softstarter. Please
note that it is not possible to use the internal thermal motor
protection or use other individual settings for each motor.
For instance, the start ramp can only be set for an average
starting ramp for all the connected motors. This means that
the start time may differ from motor to motor. Similarly, the
load monitor alarm levels/margins are applied for the
average shaft power value of the connected motors. In order
to work around this kind of problem, it could be necessary
to deactivate a number of functions and alarms.
For motors connected in parallel, torque control is not
recommended because of the risk of oscillation between the
motors. Voltage control with or without current limit is
recommended instead. The use of the braking functionality
is not recommended for motors connected in parallel.
Note, by using the Emotron TSA built in PTC plus optional
PTC/PT100 boards it is possible to have individual PTC
protection of up to 3 motors.
4.4.6 Running motors linked
together
When starting and running motors mechanically linked
together but with one softstarter connected to each motor,
there are two kinds of operations available. The first is to
start the motors at the same time using voltage control with
or without current limit. The second is to start one motor
first with torque or voltage control and after the motor has
reached full speed, the voltage to the other motors is ramped
up using voltage control.
4.4.7 Heat dissipation in cabinets
For guidelines regarding calculation of heat dissipation in
cabinets, please contact your cabinet supplier. The required
data is found in “Technical Data”, Chapter 13. page 157.
4.4.8 Insulation test on motor
When testing the motor with high voltage e.g. insulation
test, the softstarter must be disconnected from the motor.
This is due to the fact that the softstarter will be seriously
damaged by the high test voltage.
4.4.9 Operation above 1,000 m
(3280 ft)
All ratings are stated for operation at maximum 1,000 m
(3280 ft) over sea level.
If the softstarter is operated at 3,000 m (9843 ft) for
example, it must be derated, and it is likely that a higher
rated model than normal is required to fulfil the task. See
further information in section 13.3.2, page 162.
4.4.10 Aggressive environment
conditions
As standard the Emotron TSA is equipped with coated
boards in order to reduce the risk for corrosion. For
specification, see section 13.3, page 161.