Yaskawa 303 User Manual

DWG. NO. 02Y00025-0299 SHEET NO. 1 OF 6 EFF. 4/24/91 (m-df)

For GPD 303, 1-5HP, or GPD 503 230V 1-10HP, 460V 1-20HP, 575V 5-20HP Adjustable Frequency Drives, or VCD 703 230V, 3-10HP, 460V 3-20HP Vector Control Drives

CHANGE RECORD

STD-5980 2-16-95

STD-4809 5-17-91

STD-5398 12-21-92

STD-5536 5-18-93

DYNAMIC BRAKING (DB) OPTION

(BRAKING RESISTOR (HEAT SINK MOUNTED) OR

BRAKING RESISTOR UNIT)

(PART NUMBERS DETERMINED BY DRIVE RATING)

Before installing this option, a TECHNICALLY QUALIFIED INDIVIDUAL who is familiar with this type of equipment and the hazards involved, should READ this ENTIRE INSTRUCTION SHEET.

IMPORTANT

This option may have been installed by the factory. However, certain steps can only be completed at the installation site. Therefore, review and perform those steps which complete the installation process.

DESCRIPTION

Installation of this option enables the motor to be brought to a smooth and rapid stop. This is achieved by dissipating the regenerative energy of the AC motor across the resistive components of the Dynamic Braking option.

Dynamic Braking Operation

Whenever an excited motor is operated in the negative slip region (or is subjected to an overhauling load), the motor will behave as an induction generator. In this mode, energy will actually flow from the motor back into the drive, as shown in illustrations (A) and (B).

This energy will cause the DC Bus voltage to rise. Another condition that will cause the DC Bus voltage to rise is when the input voltage to the drive is high. When the DC Bus voltage reaches a certain level, the Dynamic Braking option will activate. The option will actually “shunt” the regenerative energy away from the Bus capacitors, as shown in illustration (C), and will dissipate it as heat in the DB resistors. Since the regenerative energy is dissipated in the DC resistors, the Overvoltage (OV) trip is prevented; thus the motor remains excited and continues to produce braking torque. However, for the high input voltage condition, an input contactor (1M) should be used (see Figure 4) to disconnect the drive when the high input voltage exists for a long period of time.

BUS CAPS

MOTOR

(A) "MOTORING" POWER FLOW

BUS CAPS

MOTOR

DB OPTION

BUS CAPS

MOTOR

(B) "GENERATING" POWER FLOW

DWG. NO. 02Y00025-0299 SHEET NO. 2 OF 6 EFF. 4/24/91 (m-df)

Refer to Sheet 1 for latest change.

Table 1

Drive Braking Resistor Unit

Voltage HP(CT) Part Number H W D H1 W1 Mtg Screws

1 5P41-0742 13.00 12.00 5.00 9.0 11.00 3/4 (4)

2 2 5P41-0743 13.00 12.00 5.00 9.0 11.00 3/4 (4)

3 5P41-0744 13.00 12.00 5.00 9.0 11.00 3/4 (4) 5 5P41-0745 13.00 12.00 5.00 9.0 11.00 3/4 (4)

0 7.5 5P41-0746 13.00 12.00 5.00 9.0 11.00 3/4 (4)

10 5P41-0747 13.00 12.00 5.00 9.0 11.00 3/4 (4)

1 5P41-0752 13.00 12.00 5.00 9.0 11.00 3/4 (4)

4 2 5P41-0753 13.00 12.00 5.00 9.0 11.00 3/4 (4)

3 5P41-0754 13.00 12.00 5.00 9.0 11.00 3/4 (4) 5 5P41-0755 13.00 12.00 5.00 9.0 11.00 3/4 (4)

0 7.5 * 5P41-0756 13.00 12.00 5.00 9.0 11.00 3/4 (4)

10 5P41-0757 13.00 12.00 5.00 9.0 11.00 3/4 (4) 15 5P41-0758 13.00 12.00 5.00 9.0 11.00 3/4 (4)

20 5P41-0759 13.00 12.00 5.00 9.0 11.00 3/4 (4)

Figure 1. Mounting Braking Resistor on

Heat Sink of GPD 503 or VCD 703

* VCD 703, 460V 7.5HP drive does not use this part number Braking Resistor Unit,

but instead uses the part number listed for the 10HP drive.

BRAKING RESISTOR

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