ABB ACS 800 Series, Firmware Manual

Page: 88 / 340

Program features
88
Settings
Diagnostics
Torque proving (Crane system check)
Torque proving (Crane system check) consists of electrical and mechanical tests.
Both functions are tested at the same time, and if the electrical test is accepted, the
mechanical test is not continued. You can enable both functions with parameter
76.01 TORQ PROV SEL:
• electrical test with Torque proving (parameters 76.01 and 76.02 TORQ PROV
FLT TD) to make sure that electrical components are healthy.
• mechanical test with brake slip (parameters 76.01 , 42.11 MOTOR SLIP SPD and
42.12 SLIP FAULT DELAY) to make sure that the motor brake is not slipping.
Torque proving ensures that the drive is able to produce torque before it releases the
brake and starts the crane operation. The function is mainly intended for hoist drives,
but it can also be used with drives that control other crane motions if they have the
encoder feedback in use.
Torque proving gives a positive torque reference when the mechanical brake is still
on. If the Torque proving is successful, in other words, the actual torque of the drive
reaches the reference level, the drive allows the brake to open and initiates the next
step in the starting sequence.
The time to execute the torque proving sequence is so short (executed in 20 ms
cycle time) that the operator does not experience any time delay in the starting
sequence. The maximum allowed time for the torque to be proved is set in
parameter
76.02 TORQ PROV FLT TD. The drive waits for a time period of 76.02 for
the torque to be proved. An unsuccessful torque proving will trip the drive on TORQ
PROVE FLT.
The function operates as follows (see the block diagram below):
• Parameter 76.01 TORQ PROV SEL (= TRUE) activates the function.
• The output signal TORQ PROV OK is “0” until the Torque proving is performed.
Parameter Additional information
75.01 Activation of the function
75.02 Speed deviation limit
75.03 Delay for the fault trip
75.04 Speed change per second
Actual signal Additional information
03.33 bit 1 Speed match fault bit
Faults
SPD MATCH FLT Excessive speed error when running at set point or rate of change of actual
speed is low