Load Limiter – Crane Anti-Collision – Electronic Crane Scale 

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SAF-LIFT LOAD LIMITER
Crane Load Limiters start with SAF-LIFT. SAF-LIFT Load Limiters prevent inadvertent lifts that exceed the rated capacity of a wire rope hoist. They are factory set to trip at a specified load level. SAF-LIFT prevents overloads for all wire rope hoists up to ¾" in diameter. SAF-LIFT is easy to install, and requires only 5 ½ " of headroom. Aluminum and stainless steel components resist corrosion.

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Why Consider A Load Limiter?

SAF-LIFT  LOAD LIMITER -  VIDEO

Europe has already cre­ated the fol­low­ing IE60242-32 Standard:

9.2.5.5 Mon­i­tor­ing of com­mand actions

Move­ment or action of a hoist­ing machine or part of a hoist­ing machine that can result in a haz­ardous sit­u­a­tion shall be mon­i­tored. On man­u­ally con­trolled hoist­ing machines, oper­a­tors can pro­vide some of this mon­i­tor­ing. Con­di­tions that can­not rea­son­ably be expected to be mon­i­tored by the oper­a­tor will require means which may include over-travel lim­iters, motor over-speed detec­tion, mechan­i­cal over­load detec­tion or anti-collision devices.

SAF-LIFT Crane Load Lim­iter — Instal­la­tion Instructions:

STEP 1:

Remove clamps A and B and attach to dead end of hoist wire rope. The upper (A) set of clamps will grip rope securely and the lower (B) will allow a slid­ing fit on the rope.

STEP 2:

SAF-LIFT is fac­tory adjusted to the cor­rect rope ten­sion to trip on overload.

ATTEMPTING TO ADJUST UNIT WITHOUT CONTACTING THE MANUFACTURER WILL VOID WARRANTY.

STEP 3:

IMPORTANT. Check to ensure that there is no inter­fer­ence with the hoist upper limit switch and con­firm the upper limit func­tions properly.

ELECTRICAL HOOK-UP:

The switch is held closed dur­ing nor­mal oper­a­tion and is released to open con­tacts when the over­load is reached. The nor­mally open con­tacts of the switch are used and are usu­ally con­nected in series with the hoist UP con­trac­tor coil. Dif­fer­ent makes of hoists have vari­a­tions in the wiring arrange­ment and the elec­tri­cal con­nec­tions must be made by a qual­i­fied tech­ni­cian famil­iar with hoist­ing equip­ment. In the case of a 2 speed or vari­able speed hoist, a relay may be required. If prob­lems develop, con­sult your sup­plier for assistance.

DO NOT ADJUST SPRING TENSION BOLT OR SWITCH TRIP SCREW

THE UNIT IS FACTORY CALIBRATED

SAF-LIFT CRANE LOAD LIMITERACCURACY AND RELIABILITY

ACCURACY

SAF-LIFT crane over­load pro­tec­tion is designed and cal­i­brated to trip con­sis­tently within 50 Lbs of the Max­i­mum Rope Load.  Accu­racy “at the hook” depends on the hoist reev­ing.  Max­i­mum Rope Load per OSHA is the num­ber of pounds seen on one turn of the rope (tons/parts of rope).  For exam­ple, a 2 part dou­ble reeve hoist con­fig­u­ra­tion (4 rope parts) will be accu­rate to within 200 Lbs at the hook.

Typ­i­cally, SAF-LIFT crane over­load pro­tec­tion is sized for 115% of the crane full load capac­ity.  The addi­tional 15% is built into each unit to min­i­mize the pos­si­bil­ity of nui­sance trips.  Com­mon rea­sons for adding a nui­sance factor:

  • Weight of the wire rope con­tin­u­ously changes depend­ing on the dis­tance from the hoist drum to the bot­tom block.
  • Tem­po­rary attach­ments like chains, slings, spreader beams.
  • Sud­den accel­er­a­tion / sud­den snatch includ­ing accel­er­at­ing from low speed to high speed when oper­at­ing near the crane capacity.
  • Rig­ging prac­tices in a 2 hoist lift with cen­ter of grav­ity considerations

RELIABILITY

SAF-LIFT crane over­head pro­tec­tion must trip within 50 Lbs of the rope load 3 times in suc­ces­sion in order to pass our inspec­tion pro­ce­dure.  It is rec­om­mended that the device be tested to the same stan­dard annu­ally by a qual­i­fied  crane inspec­tor to ver­ify that the unit remains within this tol­er­ance.  Some rea­sons why the field tests should be con­ducted regularly:

  • Phys­i­cal dam­age to the device  (inter­fer­ence from dou­ble block­ing etc).
  • Changes to the hoist (Dif­fer­ent rope diam­e­ter etc).
  • Relo­cat­ing the unit to a hoist that it was not designed for (dif­fer­ent reev­ing / wire rope).

In most cases, recal­i­bra­tion can be done in the field dur­ing an annual inspec­tion.  If there is phys­i­cal dam­age to a unit, we rec­om­mend that it be returned to the man­u­fac­turer for inspec­tion and repair.

 

 

On-Site Manufacturing

We can cus­tomize and cal­i­brate your SAF-LIFT Over­load Pro­tec­tion Device quickly and have it on its way.

SAF-LIFT DEMO VIDEO