IMPULSE•G+/VG+ Series 4 Technical Manual
November 2022
Page 99
Dual Brake Feature
The Dual Brake feature is designed for hoist systems with redundant holding brakes. One brake is controlled by an
MFDO programmed to 00, and the second brake is controlled by an MFDO programmed to 0A. After a Load Float,
during the BE6 (Brake Test) time, one brake is left Open, while the VFD tests that the Closed brake is capable of
holding the load. After the BE6 time expires, the second brake is closed.
This feature is only intended as a method to test each brake individually. A mechanical delay system may be
required to prevent both brakes from closing simultaneously if power is lost.
NOTE:
All brake faults are annunciated by both the keypad and via a programmed digital output. Since the keypad
is not visible by the operator, an external warning device must be used to ensure proper safety of personnel
and equipment. Annunciating a brake fault can be accomplished by using one, or both, of the following
methods: 1) An indicator or strobe light that is continuously “ON”, indicating proper operation. If the light
should turn “OFF”, this indicates that the light bulb has either burned out, or there is a VFD or brake
problem. Either scenario requires immediate corrective action. 2) The use of an indicating light wired to
relay output terminals MC-MA, N.O. contact, or an audible warning device that will sound during a brake
fault condition. A 120 VAC audible warning device can be wired directly to terminals MC-MA, provided that
its ratings do not exceed the 1 Amp, 120 VAC, Inductive Spec.
If a brake fault is annunciated during a “Start” sequence, it is recommended that the crane be moved to a
safe location with the load on the hook. The hoist should only be operated if absolutely necessary. In this
type of alarm sequence, either the brake is seized or the VFD cannot develop enough torque in the motor
in the time allotted. To troubleshoot the hoist, it will be necessary to monitor the keypad on the VFD and
operate the hoist at the same time. Two people are recommended for this procedure. With one person
operating the hoist and the other person monitoring the keypad, run the hoist. The keypad should display
one of the following faults: BE1, BE2, BE3, or BE4. For corrective action,
.
If a brake fault is annunciated after the hoist has come to a complete stop, and Load Float (C08-10) has
timed out, it would indicate that the VFD has checked the brake and determined that the brake has
insufficient torque available to hold the load. DO NOT TURN OFF POWER. This condition indicates that
the brake has failed and the VFD / motor combination is suspending the load. If, during this condition, the
hoist is operated in the “Raise” direction, it will only be allowed to run at a speed equal to or less than the
“BE6 Up Speed” setting in parameter C08-18 (C08-18 is 6 Hz by default.) This is an additional indication
that the brake has failed to open, or the load is slipping through the brake. It is recommended that the crane
be moved to a safe location and the load lowered to the ground. Corrective action should be taken to repair
the brake. The keypad will be displaying one of two alarms during this condition: BE5 or BE6.
WARNING
DO NOT turn off power to the VFD during a BE5, BE6, or BE8 alarm. This may result in loss of control of the
load if the brake has failed in the open position or is unable to hold the load.
Содержание Impulse G+ series 4
Страница 20: ...IMPULSE G VG Series 4 Technical Manual November 2022 Page 20 Figure 2 1 Capacitor Reform Diagrams...
Страница 30: ...IMPULSE G VG Series 4 Technical Manual November 2022 Page 30 Figure 3 1 Typical Connection Diagram...
Страница 53: ...IMPULSE G VG Series 4 Technical Manual November 2022 Page 53 4 3 2 Menu Structure Figure 4 1 Menu Structure...
Страница 243: ...IMPULSE G VG Series 4 Technical Manual November 2022 Page 243 Figure B 5 Figure B 6 Figure B 7...
Страница 246: ...IMPULSE G VG Series 4 Technical Manual November 2022 Page 246 Figure B 8 Figure B 9 Figure B 10 Figure B 11...
Страница 248: ...IMPULSE G VG Series 4 Adjustable Frequency Vector Crane Controls Technical Manual November 2022...