ROWAN ELETTRONICA s.r.l. - Via Ugo foscolo, 20 - 36030 CALDOGNO (Vicenza)
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OPERATING PRINCIPLES
The 390S drive was designed to control the speed of Rowan high slip motors (S series) equipped with tachometrical
dynamo. It is a three-phase current adjuster with tachometric feedback which uses controlled diodes (SCR) piloted by
the system with thyristore for phase control. The voltage which pilots the motor comes from an analogue process
which keeps the revolutions constant by means of differential control between the real speed reference extracted by the
tachometrical dynamo and the speed set by the potentiometer or external analogue voltage.
When combined with a Rowan threephase high slip motor, the result is a fast system with constant couple that is
extremely quiet and uniform, from zero to maximum motor revolutions.
The choice of the controlled diodes for the power part (already overdimensioned) guarantees reliability in the case of
extra voltages or extra currents. The rotational direction of the motor is selected by exchanging 2 phases of either the
supply card or the motor itself, as is done with standard threephase asynchronous motors (to check the rotational direction
with a +10VDC signal use the 380S type bidirectional drive).
It is also possible to adjust the acceleration and deceleration ramps according to the needs of the device moved by the
Rowan threephase motor. Dc braking (which is also valid for low inertia loads or limited braking needs) starts automatically
if the ramp time of deceleration ramps with inertial loads is not respected. If the contrary is necessary, a 380S type two-
way drive should be installed. With the 390S drive it is possible to carry out combined couple-revolution control of the
Rowan three-phase motor, which can, consequently, work as an electromagnetic brake or gear. Because of this, the
combination of a 390S drive and a Rowan high slip motor could be used with excellent results in moving winders/
unwinders.
MAIN CONNECTING DIAGRAM WITH TRIMMER AND LED POSITIONS
MARCIA
STOPINRAMPA
EMERGENZA
MOTORE IN ROTAZIONE
FRENATA
POWER ON
Inner RE excited when
drive is supplied and not
in emergency (contact
closed between 9 and 12
terminals)
