Ease of control in operation is one of the most outstanding features of 'ELEKTROMAG' Clutches and Brakes. A magnetic field is generated as soon as current flows through the magnet coil. The magnetic poles are moulded into a disc with the friction material. The electromagnetic force from the field or magnet passes through the poles to attract the armature, clamping the two together tightly. Strength of the magnetic field is directly proportional to the amount of current applied. The full torque range is completely controllable from 0 to 100% simply by adjusting the D. C. Voltage applied to the coil.

The selection of the correct clutch or brake for a particular application is dependent on a number of factors. To assist designers and engineers, some detailed features of the drive which affect the choice of the clutch or brake are given below. Alternatively, the advice and services of our experts are freely available to assist in the selection and application of our range of clutches, brakes and clutch/brake units.

It is not sufficient to use a clutch or brake which will "just transmit the torque required", since the demand on a clutch when starting a high inertia load of working under high frequency cycling rates can cause clutch failure. High engagement speeds and the possibility of shock loading are also important factors affecting the size of the clutch or brake used. The torque figures quoted in this catalogue for different sizes of clutches and brakes are static torque values.

To simplyfy the selection of the correct size of unit, a series of service factors for speed, frequency of operation and type of load have been evolved and are listed below. The nominal torque requirement is calculated from the drive by means of the formula and this when multiplied by the service factors gives a "design torque". This design torque is used to select the approximate size of unit from the torque/size table. The most suitable type of clutch or brake is then selected e.g.`EM' or `RC' Clutch or `EMCB' Clutch and brake combination followed by a dimension check to ensure that it is suitable for the shaft sizes and will fit in the space available.

SERVICE FACTORS

Engaging Speed R.P.M.	S1	No. of oper. per Hour	S2	Operating conditions	S3
0-100	1.25	1-10	1	Steady load e.g. sliting machines, continuous rotary machines.	1
101-500	1.5	11-25	1.1	Moderate load e.g. conveyors, textile machines.	1.5
501-1000	2	26-50	1.5	Heavy shock loads e.g. ball mills, Crushers	2

For higher range consult 'Elektromag'.

The above three service factors S1, S2 and S3 are each multiplied together to give a combined service factor of C. Where C=S1 x S2 x S3. Thus the design torque is the nominal torque (see formula below) multiplied by C and it is this value which is used to determine the size of the clutch and/or brake to be selected from the torque rating given in the tables.
Nominal Motor Torque in Kg. M = (71620 x HP) / (RPM x 100) or (975 x W) / (RPM).

The Magnet Body and Armature is made of high permeability steel. The friction lining fixed on the magnet body/rotor is asbestos interwoven with brass wire which has a high co-efficient.

Sliprings used in `EM' Series Clutch are made of highly conductive and corrosion resistant alloy. Carbon Brushes are of hard grade quality to ensure long life and positive contact and spring loaded.

"ELEKTROMAG" Slipring Clutch comprises of a magnet body housing the coil and friction lining, armature plate and carbon brush with holder and sliprings.

When the coil is energised through the carbon brushes magnetic force attracts the armature plate and the clutch engages. When the circuit is opened the clutch disengages. The action of springs in the clutch provides for quick disengagement. There is a positive running clearance between the two sections when the clutch is disengaged.

'ELEKTROMAG' Rotor type Clutches are used in applications where the ATMOSPHERE IS DIRTY and likely to affect the slipring and carbon brushes.

These Clutches eliminate the need of carbon brushes as the coil body is stationary and a rotor rotates around the coil body. When the coil is energised the lines of force travel from the coil to the Rotor and the armature plate is attracted to the Rotor and thus engages the drive system.

CLUTCH AND BRAKE COMBINATION - TYPE : EMCB

`ELEKTROMAG' Clutch and brake combination comprises of a Clutch and Brake with a pair of armatures mounted on a common Hub and placed in between the Clutch and Brake.

The power supply unit is designed, such that when the clutch is engaged the brake is disengaged and when the brake is engaged, the clutch is disengaged.

COIL VOLTAGES FOR ALL SERIES

Normally all units are supplied with 90 Volts D. C. Coil and other voltages such as 110 V.D.C., 48 V.D.C., 24 V.D.C and 12 V.D.C. can be supplied on request at extra cost.

Power pack system suitable for input voltage of 415 V.A.C. 2 phase 50 C/s. or 230 V.A.C. 1 phase 50C/s. can also be supplied at extra cost.

ROTOR CLUTCHES 90V. D.C. TYPE : RC

TYPE	A0	B0	C0	D0	E	F	G	H	TORQ KG.M
RC-5	63	138	100	14	30	57	45	135	7.0
RC-6	50	175	100	14	45	51	50	172	13.0
RC-8	58	224	109	14	54	51	55	221	21.0
RC-10	76	272	119	25	54	51	70	268	34.0
RC-12	111	325	128	25	57	54	75	322	65.0
RC-15	130	413	140	25	61	61	85	406	97.0

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