possible to operate the motor at very high speeds that would give a very high motor terminal voltage, but this voltage is prevented by the action of the

drive. If however, the drive is disabled (or tripped) when the motor voltages would be higher than the rating of the drive without the currents to counter-

act the flux from the magnets, it is possible to damage the drive. If high speed mode is not disabled the motor speed must be limited to the levels

given in the table below unless an additional hardware protection system is used to limit the voltages applied to the drive output terminals to a safe

level.

Drive voltage rating

200

400

575

690

Ke is the ratio between r.m.s. line to line voltage produced by the motor and the speed in V/1000rpm.

High speed mode is disabled as default (i.e. Enable High Speed Mode (B28) = 0 (Disable)). The motor flux is not modified to limit the motor voltage to

the level defined by Motor Rated Voltage (B03). The motor voltage will increase as the speed is increased until the motor line voltage x √2 is equal to

the d.c. link voltage (D.c. Bus Voltage (J65)). It will not be possible to further increase the speed significantly. This mode is safe because the motor

voltage with no current flowing in the motor cannot exceed a level that can damage the drive provided Position Feedback Phase Angle (C13) is

correct for the motor. Note that if Position Feedback Phase Angle (C13) is modified by the user to change the flux level in the motor then it is possible

to damage the drive.

If Enable High Speed Mode (B28) = -1 (Limit) then the motor flux is modified to limit the motor voltage to the level defined by Motor Rated Voltage

(B03). An Over Speed.1 trip is initiated if the measured motor speed exceeds the levels defined in the table to protect the drive.

If Enable High Speed Mode (B28) = 1 (Enable) then the motor flux is modified to limit the motor voltage to the level defined by Motor Rated Voltage

(B03), but no trip is provided, and so it is possible to damage the drive without additional protection. An indication that cannot be cleared is stored in

Potential Drive Damage Conditions (L73) and saved on power-down. The motor manufacturer should always be consulted before using this mode as

care must be taken not to de-magnetize the motor.

B29

Motor Contactor Monitoring Enable

Mode

Open-loop: RFC-A, RFC-S

Minimum

Default

Type

1 Bit User Save

Display Format

Standard

Coding

When set to Off (0), monitoring of the motor contactors is disabled.

When set to On (1), monitoring of the motor contactors is enabled, where Motor Contactor Monitoring Input (B30) is monitored to determine the state

of the contactor. It is assumed that if Motor Contactor Monitoring Input (B30) = Off (0) the contactor is open, and if Motor Contactor Monitoring Input

(B30) = On (1) then it is closed. The contactor has 3s to operate before a Trip 70 (Mot con open) / Trip 71 (Mot con closd) is called.

212

Electrical

Getting

User Menu A Commissioning

installation

started

Text

Limit

Disable

Enable

Maximum motor speed (rpm)