Setting switching point for the bottom hoist limiter

The wire rope hoist has a gear limit switch with at least three switching points. The backup limiter and the top hoist limiter are set at the factory. The bottom hoist limiter must be set on site.

 

 

Lowering the load hook to the lowest hook position

*    Lower the load hook to the desired lowest hook position.

─     The load hook should not touch the floor of the building.

─     The wire rope should not be slack.

─     A certain minimum clearance must be maintained between the cable guide and the drum housing. This clearance is determined in the next work step.

─     The hook path (distance between the highest hook position (= hook headroom, C-size) and the lowest hook position) must not be greater than is specified on the type plate.

 

 

Only with wire rope hoists with one cable guide

 

Cable guide

 

Cable drum

Drum housing

*    Measure the distance 'F' between the cable guide and the drum housing and compare this with the table.

Wire rope hoist

Type

Reeving

Spacing 'F' [mm]

GM 800

E, D, DA

4/1

42 ± 2

GM 1000

E, D,
DA

4/1

2/1

56 ± 2

GM 2000

E, D,
DA, DQA

4/1

2/1

59 ± 2.5

GM 3000

E, D,
DA, DQA

4/1

2/1

73 ± 2.5

GM 5000

E, D, DA, DQA

4/1

2/1

87.5 ± 3

GM 5000

D

4/2

73 ± 2.5

GM 5000

Z

4/2

8/2

87.5 ± 3

GM 6000

E, D, DA, DQA

4/1

2/1

102 ± 3

GM 6000

Z

4/2

8/2

102 ± 3

GM 7000

D, DA,
DQA

2/1

4/1

6/1

131 ± 4

GM 7000

D

4/2

8/2

87 ± 3

GM 7000

Z, ZA

4/2

6/2

8/2

10/2

131 ± 4

 

 

 

Only with wire rope hoists with two cable guides

 

Cable guide

 

Cable drum

Drum housing

*    Measure the distances 'F1' and ‘F2’ between the cable guides and the drum housing and compare these with the table.

Wire rope hoist

Spacing 'F1' [mm]

Spacing 'F2' [mm]

GM 3000 - D

66 ± 3

66 ± 3

GM 5000 - D

80 ± 3

76 ± 3

GM 7000 - D

84 ± 3

87 ± 3

 

 

 

Warnung stürzende Last

Danger from falling suspended load!

The cable can be torn from the cable drum, causing the suspended load to fall and kill or injure people if the distances ‘F’ or ‘F1’ and ‘F2’ are not heeded. These distances guarantee that there is always enough wire rope wound onto the cable drum.

Always maintain ‘F’ or ‘F1’ and ‘F2’.

*    If necessary, raise the load hook until the distance 'F' or ‘F1’ or ‘F2’ is achieved.

●   The lowest hook position of the load hook has now been determined.

 

 

Only during normal operative travel of the bottom hoist limiter

This working step only applies if the bottom hoist limiter may be travelled to during normal operation.

 

Setting backup limiter for the bottom hoist limiter

The gear limit switch has a fourth switching point. This is used as backup limiter underneath the bottom hoist limiter.

 

At the lowest hook position previously travelled to:

Control cam

 

Adjusting screw

Microswitch

─     The backup limiter for the bottom hoist limiter is set using the foremost white adjusting screw. The gear limit switch has at least four switching points.

*    If necessary: Turn the adjusting screw until the control cam is to the right of the microswitch. It should not be either directly on or to the left of the microswitch.

*    Turn the adjusting screw to the left until the control cam presses in an anti-clockwise direction against the microswitch and an audible click is heard.

●   The main contactor switches off.

 

If the switching point is set with a different adjusting screw than previously specified, this is noted on the wiring diagram.

 

 

Adjusting screw

 

*    Turn the adjusting screw three-quarters of a turn to the right.

●   The microswitch switches again; the main contactor switches back on.

*    Raise the load hook slightly.

*    Turn the adjusting screw three-quarters of a turn back to the left.

 

 

 

Determining and approaching the braking distance in the limit switch range

*    Read off the braking distance from the table.

This braking distance is determined by the LIS-SV and is not identical to the braking distance during lifting/lowering in normal crane operation.

 

Lifting speed 3000 rpm

Lifting speed 6000 rpm

Reeving
2/1 and 4/2

320 mm

1280 mm

Reeving
4/1 and 8/2

160 mm

640 mm

Reeving
6/1 and 12/2

106 mm

480 mm

Reeving
10/2

128 mm

512 mm

Reeving
6/2

213 mm

853 mm

 

 

Lowest hook
position plus braking distance

 

Floor of building

Lowest hook position

*    Raise the load hook until it is exactly at the braking distance to the lowest hook position.

 

 

Setting bottom hoist limiter

At the lowest hook position with braking distance previously travelled to:

Microswitch

 

Adjusting screw

Control cam

─     With gear limit switch with three switching points: The bottom hoist limiter is set using the foremost white adjusting screw.

─     With gear limit switch with more than three switching points, where additional switching points are provided in the traversing range of the load hook: The bottom hoist limiter is set using the foremost white adjusting screw.

─     During normal operative travel of the bottom hoist limiter: The bottom hoist limiter is set using the second white adjusting screw from the front.

*    If necessary: Turn the adjusting screw until the control cam is to the right of the microswitch. It should not be either directly on or to the left of the microswitch.

*    Turn the adjusting screw to the left until the control cam presses in an anti-clockwise direction against the microswitch and an audible click is heard.

 

If the switching point is set with a different adjusting screw than previously specified, this is noted on the wiring diagram.

 

 

Checking the setting

*    Raise the load hook.

*    Lower the load hook at both slow and fast lifting speed and check whether it halts at the lowest hook position.

 

 

Display of impulses

 

●   The counted impulses of the encoder are shown in the LIS-SV display.