LIFTING MAGNETS

INSPECTION AND VERIFICATION

FOR MAGNETIC LIFTING SYSTEMS

Norms:

  • UNI EN 13155:2009 Lifting equipment
  • Safety - Removable load handling equipment
  • Other norms:
  • ASME B30.20, “Below-the-Hook Lifting Devices”

GO TO VERIFICATION PROGRAMM

CHECKS FOR SAFE WORKING

Magnetic lifting equipment must be subjected to periodic checks, testing its correct functioning. The check must include the verification of the overall state of the magnet and of the safety devices that prevent any possible accidental deactivation, of the regular identification (data plates) and of the capacity by means of a tear-off test.
The pull test must give as a result a minimum value three times higher than the declared capacity value, under the conditions established by the manufacturer.
Our service center is equipped with certified equipment for the periodic checks of any magnetic lifter, in the event of a positive result of the tests, a certificate is issued with the results of the checks and the requirements necessary for correct operation.

DIFFERENT KIND OF LIFTERS

MAGNETIC LIFTING SYSTEMS

Permanent-Magnet Lifters

They exploit the intrinsic magnetic energy of the built-in permanent magnets and are activated by a lever, which rotates a group of magnets so that the magnetic flux passes through the load (working phase) or closes inside the magnet itself (phase release). These lifters are suitable for handling loads up to a maximum capacity of 3,000 kg, and are mainly used for storage, transport and loading of machine tools. They can work on "cold" materials (T≤70 ° C). THEY ARE INHERENTLY SAFE.

Electropermanent Lifters

They use the intrinsic magnetic energy of the built-in permanent magnets, but the magnetization or demagnetization command is done impulsively (a few seconds max.) By means of a coil, which reverses the polarity of a group of magnets, causing the flux magnet passes through the load (work phase), or closes inside the magnet itself (release phase). Once the current impulse has ceased, the lifter is completely independent from any external energy source, remaining in its ON or OFF state. These lifters are suitable for handling compact loads (billets, slabs, single sheets, rounds, cold rolled coils, etc.), with capacities over 45t. They can be installed in groups on sling bars, in order to lift even flexible loads. They can work on hot materials with temperatures up to 500 ° C. THEY ARE INHERENTLY SAFE.

Battery powered Electropermanent Lifters

Similar to the previous ones, but powered by a battery on board the magnet. On the magnet there is an indicator of the battery charge level: below a minimum level, work must be stopped and the battery must be recharged. These lifters are suitable for handling loads up to a maximum capacity of 4,000 kg and are mainly used for storage, transport and loading of machine tools. They can work on "cold" materials (T≤70 ° C). THEY ARE INHERENTLY SAFE.

Electromagnetic Lifters

They exploit the electricity from the network to power the coils incorporated in the electromagnet itself, which generate the necessary magnetic field. The holding force can be affected by network problems (interruptions or fluctuations) or by faults in the coils or power system. For this reason they must be equipped with emergency batteries, which guarantee the holding of the load for the time necessary to restore the network. These lifters are suitable for handling any type of load, even loose (scrap) or bundles with capacities over 45t. They can be installed in groups on sling bars, in order to lift even flexible loads. They can work on hot materials up to a temperature of 650 ° C.

Battery powered Electromagnetic Lifters

Similar to the previous ones, but powered by an on-board magnet battery. On the magnet there is an indicator of the battery charge level: below a minimum level, work must be stopped and the battery must be recharged. The holding force can be affected by battery problems, coil failures or power system failures. These lifters are suitable for handling loads up to a maximum capacity of 4,000 kg and are mainly used for storage, transport and loading of machine tools.

FAQs

INSPECTION AND MAINTENANCE CHECKS
Inspections
to be carried out		 Daily Weekly Monthly Yearly Note
Visual O
General Check O M
Functional inspection
(lever adn safety)		 O M
Corrosion Check O M
Cleaning O M
Plates
(must be readable)		 O M To be change if not readable
Hooks M Deformation <10%
Magnetic Poles integrity M Dent <10%
(if more, grinding)
Test tear force M Contact your dealer
O = Operator | M = Specialized worker

HOW OFTEN SHOULD I CHECK A MAGNETIC LIFTER?

the work equipment must be subjected to periodic checks, according to frequencies established on the basis of the indications provided by the manufacturers, or by the rules of good technique, or in the absence of the latter, inferable from the codes of good practice. [ISO 9927: 2013 and ISO 12482-1]:

DAILY GENERAL INSPECTION:
  • Check the general conditions and functions of the sliding parts and locking pins and of the magnetic lifter, according to the instructions contained in the use and maintenance manual.
  • In the event that the lifting eye should be visibly damaged, replace it immediately.
  • Damaged and / or illegible parts of the data plates and flow charts must be replaced immediately.
  • Inspection carried out daily by the crane operator or slinger before starting lifting operations; consists of a visual inspection or functional tests;
In case of anomalies, stop using the magnetic lifter and contact the technical assistance center.

FREQUENT INSPECTION:
  • inspection conducted on the basis of the frequency and severity of use of the equipment and the work environment, within time intervals not exceeding three months (unless periods of inactivity);
PERIODICA INSPECTION:
  • inspection conducted on the basis of the working environment, frequency and severity of use of the equipment, within time intervals not exceeding 12 months (unless there are periods of inactivity);
It is recommended to subject the lift to a verification of the magnetic field produced at least once a year (contact the maintenance technician / manufacturer), to verify its performance.

HOW to carry out the checks, concerns the inspection method:
  • VISUAL EXAMINATION: examination conducted in order to identify any anomalies or deviations from normal conditions by means of visual checks. Generally the examination is conducted without disassembling the equipment, unless there are special needs that arise;
  • NON-DESTRUCTIVE CHECKS: reference is made to examinations such as penetrating liquids, ultrasounds, magnetic particles, radiographs, which may be necessary downstream of the visual examination;
  • FUNCTIONAL TESTS: these concern the controls, switches and indicators. As regards, instead, the electrical and / or hydraulic system, the test must be conducted, only if necessary;
  • OPERATIONAL TESTS: includes tests with and without load and functional tests of the limiting and indicator devices.

WHO can carry out the checks
The checks can be performed by the same person, as long as they have all the specific skills to perform them. It should also be noted that these figures must not be specifically recruited by the employer, but may coincide, subject to possession of the requisites necessary for the performance of the tasks provided, with the staff employed by the employer.
  • CRANE DRIVER: person who operates the crane in order to position loads. He is responsible for the correct handling of the equipment. They must be adequately trained for the specific type of crane and have sufficient knowledge of the crane, its controls and its safety devices.
    COMPETENCE: DAILY CHECK
  • MAINTENANCE PERSONNEL: personnel responsible for the maintenance of the crane and its safe and satisfactory operation. It is required to carry out any necessary maintenance. He must be fully familiar with the equipment and the risks it presents and with the required intervention procedures. [EN 12480-1].
    COMPETENCE: FREQUENT CHECK
  • EXPERT TECHNICIAN: person who, due to his preparation and experience, possesses skills and knowledge in the field of cranes and sufficient familiarity with the main regulations to be able to determine any deviations from the foreseen conditions. [ISO 9927].
    COMPETENCE: PERIODIC CHECK

PRINCIPAL RISKS:

The main safety hazard associated with their use is related to the fall of the load due to a failure of the lifting accessory with consequent loss of power. Among the factors that can compromise the stability of the load: incorrect application (e.g. non-ferromagnetic material, air gap, load geometry, temperature, etc.) or malfunction / state of maintenance, lack of mains voltage or failure of the power supply system .
An additional potential health risk for people working in the vicinity of these magnetic lifting accessories is the static magnetic field around the magnet which could interfere with the operation of electronic devices (e.g. cardiac pacemakers) used by personnel or attract prostheses implanted in the human body.
The magnetic field could also interfere with communication and control systems / equipment that could be relevant to safety.

SAFETY MEASURES:

Power Failure Protection - With the exception of permanent magnet, electropermanent or battery powered electropermanent lifters, any power failure could cause the load to be released. Consequently, for electromagnetic lifting accessories, having a capacity greater than 20 kg and powered by the mains, an automatic battery intervention system must be provided, which, in the event of a power failure, is able to hold the load provide an audible or visual ALARM. The battery must be able to hold the load safely for a minimum of 10 minutes;
After the automatic battery intervention device has been activated, the load deposited on the ground and the electromagnet has been de-energized, it can no longer be used until the power line returns. In the event that the battery has discharged below a minimum value set by the manufacturer, the operation of the electromagnet will be inhibited when the power returns, until the state of charge has reached the minimum required value.

RISKS EVALUATION:

A correct risk assessment must be developed when introducing this type of lifting accessories, also with the help of the information provided by the manufacturer of the equipment. In particular, it must be considered whether such equipment is appropriate and adequate in relation to the nature of the load and the operations to be performed.
Furthermore, the risks deriving from the presence of people in the immediate vicinity of the loads must be taken into consideration. Finally, in the VdR document, the control planning plan for the maintenance of accessories must be provided, together with the information, training and specific training to be transmitted to the workers in charge of lifting operations.
Some fundamental FACTORS to consider for a safe and correct use of the lift are:
  • Dimensions and maximum weight of the load to be lifted (= nominal capacity) and the lifting accessory;
  • Thickness of the load (which can reduce the effective capacity of the lift);
  • Composition of the steel constituting the material to be handled: alloy steels have a different magnetic behavior depending on the content of the alloy elements present, which is reflected in a variation in the capacity of the magnet;
  • Nature of the load, it is necessary to know if the loads must be taken individually (e.g. slabs, coils and sheets, beams), overlapping (e.g. sheets), in layers (e.g. billets, rounds, pipes, beams), in bundles (rods and merchant bars) or in bulk (eg scrap);
  • The nominal capacity of the lifter or the weight of the maximum load to be lifted;
  • The capacity of the lifting system which must be greater than or equal to the sum of the weight of the lifter and the nominal capacity of the lifter;
  • The flatness of the load (eg for billets, sheets, bars and slabs);
  • The Flexibility of the load (eg: sheets, bundles);
  • Air gap: this term refers to the distance that is created between the poles of the magnet and the contact surface of the material, due to surface defects, dirt, non-magnetic material interposed (e.g. paint, oil, paper, etc. ). The distance between the poles of the magnet and the surface of the load (the so-called air gap) can compromise the performance of the lifting accessory. Therefore, it is necessary to ensure good contact between the magnet poles and the load, for optimum and safe performance.
  • Material temperature: the standard execution provides up to 70 ° C, but special executions can reach up to 650 ° C;
  • Frequency of use: if the use is very high (frequent and / or repeated maneuvers), the reduction in efficiency due to the heating of the winding must be taken into account; unless otherwise indicated, a standard cycle intermittency ED equal to 60% must be considered (from the German: Eintschalt Dauer = duration of insertion), which indicates the percentage in which the electromagnet can be kept excited with respect to the reference time. 10 min .: for example, an ED equal to 60% means that, over a total cycle time of 10 minutes, the magnet can stay energized for a maximum of 6 minutes (ON) and 4 minutes de-energized (OFF); if this ratio is exceeded, the electromagnet heats up excessively and, in the long run, there is a risk of compromising the insulation of the winding, with consequent discharge to ground or the formation of short circuits;
  • Duration of movement with load (magnetization / demagnetization cycle): the magnetization must not last more than "ED%" x10 minutes continuously, to avoid the risk of the electromagnet overheating and its damage (see above).
  • Surface profile of the materials to be lifted. Non-uniform surfaces (eg corrugated, polygonal, corrugated or perforated sheets), can be raised by means of magnets, but the percentage of the load surface actually in contact with the magnet poles must be evaluated.
  • Round and tube lifting. In the case of lifting pipes and rods, unless otherwise provided by the manufacturer of the equipment, a reduction in capacity must be taken into account. Therefore, the capacity is not the nominal one but it is necessary to refer to the plate on the magnetic lifter. In both cases it is necessary to check the indications provided by the magnet manufacturer.
  • Lifting of multiple loads. (e.g. sheets) in the case of lifting multiple sheets it is necessary to perform the PARTIAL MAGNETIZATION of the electromagnet, lift slightly to check that the desired number of sheets has been hooked (compatibly with a safe lifting) and, if is correct, maximize the magnetization and complete the desired handling of the sheets.
  • Lifting of bulk loads (scrap) - during the handling of scrap, the penetration of the magnetic flux may not guarantee the secure grip of the outermost parts of the load and cause parts of the same to fall, even if the rated capacity has not been exceeded . For the above, the area where the load is handled must not be accessible during handling (NO GO AREA). The operator assigned to the operations must make sure that no one is inside the handling and passage area of the magnetic accessory, before starting any maneuver. In particular, in the case of handling scrap, the risk of parts being released is possible, given the type of bulk cargo.
  • Nature of the lifting operation - An unbalanced load can compromise the grip of the magnet. To do this, it is necessary to position yourself on the center of gravity of the load.
  • Lifting loads with multiple magnets - When multiple magnets are used for lifting loads, they are usually fixed on a crossbar. The magnetic suspension must be chosen so that there is a distribution of the load as uniform as possible on the individual magnets, and that the magnets can adapt to the surface of the lifted load.
  • Lifting equipment suitability assessment - Magnets connected to lifting equipment: the weight of the magnet, its accessories and the load to be lifted must be taken into account when assessing the load capacity and safe operation of the lifting equipment ACCESSORY MASS + LOAD MASS ≤ LIFTING DEVICE CAPACITY
    Magnets attached to mobile cranes; in this case, in addition to the weight of the magnet, its accessories and the load to be lifted, the effects of inertia during rotation and movement must also be taken into consideration. In addition, the risks associated with the sudden release of the load before it is grounded must be assessed. For this purpose, it is necessary to check from the manual of the mobile crane manufacturer the possibility of using the magnet in consideration of the stresses induced following the use of the magnet. In fact, the manufacturer could prohibit such use or advise to reduce the range in case of using magnets.
  • Power failure. Suspended load - The lack of electricity could cause the load to be released and cause damage to things and people. For this purpose, it is necessary to prepare emergency management procedures (for example actions to be taken in the event of a power failure aimed at descending the load and / or handling the loads safely).
  • Lifting of bundles it is essential to implement technical and organizational measures aimed at protecting people, plants and machinery from the risk of falling material. In particular, electromagnets can be used to lift bundles of materials after evaluating the suitability of the load containment bindings. This is because the depth of field generated by the electromagnet can vary from half to two thirds of the thickness of the load. The handling area must be adequately signaled and forbidden to the passage of people as there is a risk of releasing part of the load in the event that the containment bindings break during the lifting and handling phase.
  • For the purposes of a correct risk assessment, in addition to the factors described above, it is also necessary to adopt measures aimed at implementing: Specific training of operators Maintenance checks

SAFETY PROCEDURES:

The workers in charge must have all necessary information and instruction and receive adequate training and training in relation to safety in relation to:
a) the conditions of use of the equipment;
b) to foreseeable abnormal situations.
For this purpose, it is necessary to prepare, for each type of lifting accessories, safety operating instructions concerning their safe use. These instructions must be made available to the workers in charge. In addition, the detailed tables of the maximum loads for each type of material (eg sheets, bars, tubes, etc.) be conveniently displayed.
Safety operating procedures:
  • Use the type of accessory suitable for the load (eg mass, material, shape, etc.) to be lifted and be aware of the limits of each equipment;
  • Lift one piece of material at a time. Obviously this indication is unsuitable for handling scrap, etc. In the case of lifting several pieces, consult the instructions for use;
  • Always follow the instructions provided by the manufacturer of the equipment (instruction manual);
  • Do not use magnetic lifting accessories to handle gas or liquid containers;
  • Check the thickness of the materials before lifting and compare the tables relating to lifting capacities of different thicknesses;
  • Make sure that the magnetic lifting accessories are checked before each use to check for any flaws or defects;
  • Make sure there is good contact between the magnet surfaces and the load. In fact, the magnetic efficiency could be affected by the air gap.
  • Take into account the flexibility of the load. Any slingbar used must be suitable for the purpose.
  • If more than one magnet is to be used, it is important that the center of gravity of the load is ascertained so that the load taken by each magnet can be established. It is important that the range of each individual magnet is not exceeded.
  • Implement technical and organizational measures aimed at ensuring that the user is at a safe distance from the load being handled. When waste material (eg scrap) is lifted all people should be excluded from the scrap handling area (no go area). Provide operators with safe workplaces to ensure that they cannot be hit by loads.
  • Display suitable warnings at entrances to places where lifting is taking place. Prevent unauthorized access to the "dangerous area";
  • All material movements must be properly organized and managed to avoid injury and damage to plants and people. To this end, lifting operations and procedures must be clearly defined and followed.
  • Move the load as low as possible, as far as possible no higher than 1.5 m above ground level. Where this is not possible, other precautions should be considered (eg the application of "extended exclusion zones);
  • Before disconnecting the socket plug, the magnet must be OFF (de-energized), to avoid, in the event of opening under load, the formation of an electric arc, dangerous for the person who disconnects the accessory.
  • Before leaving the workplace, it is necessary to deposit the load: never abandon the lifted load!
  • Prepare emergency management arrangements e.g. actions to be taken in case of power failure / equipment, etc.

SAFETY CHECKS:

  • The use of the lifting accessory is allowed only to informed, trained and trained workers;
  • Check that the material to be lifted is ferromagnetic and that the shape, mass, etc. load are suitable in relation to the accessory to be used;
  • Check that the lifting accessory is provided with the relative plate showing the capacity diagrams and that it does not have any flaws or defects and that it has been subjected to maintenance checks (with the latest favorable outcome);
  • Check the condition of the magnet each time before use. Clean the polar surfaces of the magnet and the contact surface of the workpiece to be lifted.
  • Make sure the load is properly distributed for the lift being used.
  • The thickness of the load to be lifted and the air gap are factors to be taken into consideration before starting the lifting operations. Therefore, it is necessary to compare them with the plate applied to the accessory or with the information given in the instruction manual.
  • During use, follow the instructions provided by the manufacturer and in any case keep a safe distance from the load
  • Don't lift people
  • Do not allow the load or the magnet to come into contact with any obstacles.