"ELECTRO MAGNETIC FLUX" lifting magnets for heavy duty application are designed on the basis of research in this specialized field. The most favourable dimensioning of all components was determined by thorough mathematical and measuring studies of all factors affecting on performance. Experiments on models and fullscale prototypes were carried out to determine such features as usable and stray magnetic flux; influence of field line length and iron cross section; temperature drop from hottest point to magnet surface; thermal properties of the entire magnet; suitability of materials and production methods.
All "ELECTRO MAGNETIC FLUX"  lifting magnets are of weatherproof design for outdoor use. Completely sealed submersible models are available for dipping into water-field containers or underwater salvage and similar work.

MAGNET BODY
Mechanical construction of "ELECTRO MAGNETIC FLUX"  high capacity lifting magnets is very sturdy to meet toughest demands in service. The one piece magnet body is cast from high-grade dynamo steel. Underneath, between centre and outer poles, the magnet body is closed by sturdy, cast and rib-reinforced non-magnetic austenitic manganese steel plate. Fastening at the centre pole is effected by means of a shrunk-on ring, and at the outer pole by locking ring.
The standard three-fall chain suspension, designed with common suspension ring is rated to meet all normal duty load. Special change are available on request for extremely heavy loads.
Two lugs for guide ropes are fitted as standard.

COILS
Standard exciter coils are wound with Anodised aluminium conductor or fiber glass covered varnish bonded aluminium conductor. Coils wound with anodised aluminium conductor offer the following advantages:

1. greater filling factor
2. Better heat conductivity.
3. Higher resistance to thermal strain.

Coils are cast into their magnet body with a special resin compound of excellent heat conductivity and thus rigidly fixed in position. In special cases, coil can be furnished with copper conductor. Use of special resins loaded with fillers as sealing compound ensures reliable conduction of heat to the magnet surface, maintaining high magnet performance over long, continuous service. All insulation materials confirm to class " H" .

DUTY CYCLE

The permissible relative duty factor is 75% / 10 mins. or 60% /10 mins. depending on magnet construction and application. The standard operating voltage is 220 volts DC. Magnets for extra heavy duty or handling of hot materials are available on request.

TABLES FOR CIRCULAR LIFTING MAGNETS TYPE : LMH-SUPER

CABLE TERMINAL BOX
The cable terminal box is of robust construction to meet toughest practical service and it consists of the following parts :

1. Cast compartment (back) for exciter coil connection.
2. Line connections from back to front compartment.
3. Front compartment for connecting the cable.
4. Terminal board for connecting the cable.
5. Gland bolt for sealing the cable.
6. Cable collar to limit load on cable.
7. Back and front compartment covers are fitted with watertight gaskets, secured with socket head screws.
   
8. Solid and fracture-proof protective cover made of cast steel incl. set screw.

This cable terminal box is constructed for durability. However, it is only fully efficient and secure when the cable is held by the bland bolt, also when the two compartments are closed tightly by means of the covers, and when the protective cover is secured by the set screw.

ELECTRICAL SWITCHGEAR

Switchgear used for the control of lifting magnets must be provided with adequate protective gear to limit the voltage generated when the inductive exciter circuit is switched off. Provisions must also be made for a brief counter flow current surge to de-energise the system and throw off the load.

We supply a wide range of plant and switch gear to feed magnets from 3-phase or DC power mains or generators, in standard and special purpose models to suit all requirements.
To ensure continuity of operation and guard against the danger of accidents in case of power failure, we also supply complete equipments for stand-by or buffer battery operation.
Where the crane driver cannot keep the magnet under visual observation ( e.g. special magnets used for raising material under water) electronic instrumentation can be fitted giving optical or acoustic signals to indicate that the load has been seized or released.

IMPORTANT NOTES ON TABLE

Rated power input for cold magnets listed in column 2 governs selection of suitable electrical equipments. In continuous service heating of the exciter winding reduces input power.
Tear-off forces relate to a level, solid, thick slab and an air gap corresponding to 1/300 and 1/20 resp. of outer magnet diameter.
Lifting capacities are average values which may be exceeded or not be reached. In actual duty, since the volume seized in each lifting operation depends largely on type, shape, alloy distribution and piling of the material.

ELECTRICAL ACCESSORIES
The following electrical accessories are required with the lifting magnet and are available from “ELECTRO MAGNETIC FLUXâ€� 

1. Transformer rectifier set or DC generator.
2. Contactor Panel.
3. Cable reeling drum.
4. Master controller.

Note : The design, dimensions and specifications are subject to alterations without prior notice due to constant development for better performance.