Braking resistor Braking resistor types for Infranor drives

Braking resistors for Infranor drives ! This is a general manual describing various braking resistor types for servo drives having output capability suitable for driving AC brushless sinusoidal servo motors. Instructions for storage, use after storage, commissioning as well as all technical details require the MANDATORY reading of the manual before getting the drives operational. Maintenance procedures should be attempted only by highly skilled technicians having good knowledge of electronics and servo systems with variable speed (EN 60204-1 standard) and using proper test equipment. The conformity...

Braking resistors for Infranor drives Content PAGE

Braking resistors for Infranor drives Chapter 1 - General description 1.1 - POWER FEEDBACK SYSTEM VIA A BRAKING RESISTOR All Infranor drives are equipped with the power feedback system. When the motor is decelerating, especially with high inertia and high speed, the mechanical braking energy is reflected to the drive. This energy is dissipated inside a resistor called "braking resistor". In order to avoid over-heating in the drive cabinet, particular care must be given to the thermal aspect. It MUST be mounted out of range of heat sensitive and inflammable elements (plastic, cable sleeves, etc.)....

Braking resistors for Infranor drives The rated power is the value given by the resistor manufacturer. At this power, the rise in temperature of the resistor reaches 350°C in free air cooling.

Braking resistors for Infranor drives VERTICAL MOUNTING IS MANDATORY

Braking resistors for Infranor drives

Braking resistors for Infranor drives The braking resistor MUST be mounted out of range of heat sensitive and inflammable elements (plastic, cable sleeves, etc.). In order to avoid any EMC or electrical problem, some rules must be observed: • heat must be evacuated, • shielded cable or at least twisted wires must be used, • wires must bear high voltage and high temperature (recommended type: UL1015, AWG 14) • wires must be as short as possible (max. 1 m).

Braking resistors for Infranor drives 2.4 - OPTIMIZING THE BRAKING RESISTOR The braking resistor can be chosen according to the drive reference. However, this choice is not optimized for a lot of applications. The following method allows the designer to optimize the braking resistor. Two different quantities are necessary to completely define a braking system: - The peak power: o It defines the deceleration energy, o It is limited by the braking transistor current. The average power: o It defines the heat dissipation 2.4.1- Estimation of the regenerative power The regenerative power must be calculated...

Braking resistors for Infranor drives 2.4.3 - Average power The required average power must be calculated to correctly choose the size of the braking resistor and to take into account the heat dissipation effect into the near environment. PELEC (n, p)  TDEC (n, p) TCYCLE Power managed by the drive axis n during the deceleration phase p, in W 2.4.4 - Braking I²t setup PI ² t  With: PI²t: Maximum average power (in W) allowed by the braking I²t function, in W tON: Conduction time allowed by the braking I²t function, in ms UBRAKING: Triggering threshold of the braking system, in V RBRAKING: Braking...