IMPULSE•G+/VG+ Series 4 Technical Manual
November 2022
Page 88
5.2.11 Load Float 2
When Load Float (C08-10) is enabled, it maintains the motor shaft at a stationary position with brake open. The Load
Float 2 (MFDI=35) function triggers the VFD to go into Load Float for the time set in C04-01. During this time, the VFD
will open the brake and hold the motor at a zero position. A FWD or REV run command takes priority over this
function.
Table 5-27: Load Float 2 Parameter Settings
* Dependent on kVA (
≤
30 HP: 10; > 30 HP: 20)
5.2.12 Load Check II™
The Load Check II function is a load-limiting feature which ensures the programmed load limit of the hoist is not
exceeded. It prevents the lifting (and potential stall) of a load that is overweight. When an overload condition is
detected, further lifting is restricted. The load may then be lowered at the speed that is specified by the Load Check
Alarm Speed (C05-08).
5.2.12.1 V/f Operation (A01-02 = 0)
When using Load Check II in V/f, motor current (U01-03) is compared to values stored during the Load Check set
up process. If they exceed the values for the active Load Check Zone, the motor will stop based on the LC Alarm
Action (C05-02) and display a Load Check alarm (LC).
NOTE:
If an application requires Load Check to be bypassed, program an MFDI to 69 (N.O.) or 6A (N.C.).
NOTE:
It is highly recommended to use OLV or FLV control methods for Load Check II.
5.2.12.2 OLV and FLV Operation (A01-02 = 2 and 3)
When using Load Check II in Open Loop Vector or Flux Vector, motor torque (U01-09) is compared to values
stored during the Load Check set up process. If they exceed the values for the active Load Check Zone, the motor
will stop based on the LC Alarm Action (C05-02) and displays a Load Check alarm (LC).
NOTE:
If an application requires Load Check to be bypassed, program an MFDI to 69 (N.O.) or 6A (N.C.).
NOTE:
The Load Check II function will alter the acceleration time, depending on loading. It must be disabled when
using two or more hoists to lift a single load.
Parameter
Display
Function
Range
Default
C04-01
Load Float Time2
Maximum duration of Load Float 2 time when
MFDI = 35
0–65535 sec
10
C04-02
Load Float Gain
Gain for the control loop to hold the load from
moving during load float
0–100
10*
DANGER
Load Check II is designed to limit loads less than or equal to the crane’s rated capacity. Consult the factory and
crane manufacturer before calibrating Load Check II with a load heavier than the crane capacity.
