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SINUS PENTA
PROGRAMMING
INSTRUCTIONS
336/452
37.
BRAKING
RESISTANCE
MENU
3 7.1.
Overview
The Braking Resistance Menu enables the clamp transistor command and sets its max. duty cycle in the drive braking
resistance. If no braking resistance is installed, promptness of the DC bus voltage control can be adjusted in order to
avoid OVERVOLTAGE alarm, causing abrupt deceleration.
To enable the clamp transistor command for the braking resistance, set
C210=[With resistor]
. In this operating mode,
when DC bus voltage exceeds a preset threshold value depending on the drive voltage class, the clamp transistor
closes in the braking resistor, so energy in excess is dissipated to the resistor and DC bus voltage does not exceed
voltage ratings.
The max. duty cycle of the braking resistor is parameterized with
C212
and
C211
: maximum duty cycle (100 * Ton /
(Ton+Toff) [%] ) and maximum time of continuous supply (Ton) respectively. If the braking resistor activation is Ton =
C212
, when this interval is over, the relevant command will be disabled for a time equal to Toff = (100 –
C212
) *
C211
/
C212
[sec].
Example
:
A lifting application featuring a Sinus Penta 0086 at 400V requires a braking resistor with a 50% duty cycle. The
braking period is 30s. According to the tables in the “Braking Resistors” section (
Installation Instructions
manual) the
applicable braking resistor is 10
– 24 kW.
The max. continuous duty for said resistor is 62s: the braking period is then compatible with that rating. Otherwise, a
higher rated resistor should be applied.
Parameter setting:
C210
=
[With resistor]
.
C211
=30s
C212
=50%
Factory-setting assumes that no braking resistor is provided. In this case,
C210
sets promptness, with respect to
variations of DC bus, for the deceleration ramp slowing-down, in order not to overload the bus capacitor bank.
If
C210
is set to zero in FOC control, deceleration slows down when given values of the voltage bar are reached
(depending on the drive voltage class).
If
C210
is > 0, DC bus voltage is controlled by considering the derivative of the bus voltage. The higher the value in
C210
, the lower the values for voltage variation affecting deceleration ramp times.
NOTE
The clamp transistor is not commanded if the drive is supplied from a Regenerative
source (see
C008
= xT Regen, where x can be 2, 4, 5, or 6 ).