Electromagnetic Transformers Guidelines for installation

Basic requirements:

• Lighting installations operating at “safety extra low voltage” (<50 V) must be supplied by a The transformers suitable for surface mounting are installed in (false) ceilings such that Note: preference should always be given to dichroic lamps, which not only reflect the light forward, but also a substantial proportion of the generated heat. - Compartment - Keep sufficient clearance from adjacent transformer, in order to avoid influence of heat. safety transformer indicated by the symbol . The primary and secondary windings of a safety transformer are isolated electrically by means of double or reinforced insulation.• A distinction is drawn between transformers which: - Are suitable only for building in . - Are suitable for surface mounting (in (false) ceilings), and therefore also for building in.• Safety transformers suitable for surface mounting have Safety Class II . • The use of short-circuit proof safety transformers is to be recommended. • Safety transformers which are not short-circuit proof have minimum protection in the form of a thermal fuse, which switches off the transformer in the event of overheating. • The transformers must be installed such that they are adequately protected against accidental contact, overload and short-circuits, in order to prevent hazards to persons or property.

Normalisation and Directives:

• Electromagnetic transformers conform to the safety regulations laid down in European standard Device Standard Max. temperature EN 60 742 , EN 61 558 and the national standard VDE 0551 . Transformer EN 60 742 105°C EN 61 558 Transformer VDE 710.14 115°CNote: transformers bearing the MM symbol have additional protection in the form of a thermal fuse.The wires connecting the transformer to a • in conformity with the European low voltage directive 73/23/EEC which came into force on January the first 1997. This directive applies to all electrical products working with an alternating voltage of minimum 50V. cable or busbar system must have a cross-section of not less than 4 mm • The ENEC, CEBEC and KEMA approval marks provide “independent” proof of conformity with the standards stated.
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Installation and assembly:

In view of the relatively high currents flowing on the secondary side of the transformer (20 x Ipri), the distance to the lighting element should always be kept as short as possible. This is necessary in order to limit the cable cross-section, taking into account an assumed voltage drop of

Protection against overload and short-circuit

5% in order not to affect the luminous colour adversely (see modern table). Basic rules: 1. Both the primary and the secondary conductors must be protected against overload and short-circuit. The choice of the protection depends among other things of type and the length of the conductor as well as of the short circuit current (see installation regulation).2. The
P (W) In (A) Max. Length (m) of a 2-core copper conductor of following cross-section: 11,5V 1,0 mm 2 1,5 mm 2 2,5 mm 2 4,0 mm 2 6,0 mm 2 10 mm 2 16 mm 2 10 0,8 18,5 27,8 20 1,7 9,3 13,9 23,1 35 2,9 5,3 7,9 13,2 21,2 40 3,3 4,6 6,9 11,6 18,5 27,8 50 4,2 3,7 5,6 9,3 14,8 22,260 5,0 3,1 4,6 7,7 12,3 18,5 30,9 75 6,3 2,5 3,7 6,2 9,9 14,8 24,7 39,5 100 8,3 1,9 2,8 4,6 7,4 11,1 18,5 29,6 150 12,5 1,9 3,1 4,9 7,4 12,3 19,7 200 16,7 1,4 2,3 3,7 5,6 9,3 14,8 250 20,8 1,9 3,0 4,4 7,4 11,8 300 25,0 2,5 3,7 6,2 9,9 350 29,2 2,1 3,2 5,3 8,5 400 33,3 2,8 4,6 7,4450 37,5 2,5 4,1 6,6500 41,7 3,7 5,9550 45,8 3,4 5,4600 50,0 3,1 4,9630 52,5 2,9 4,7 transformer must also be protected against overload and short-circuit.The protection of short-circuit proof transformers serves also as a line-protection, on the condition that the minimum wire diameter and maximum length are respected (see installation and assembly).Where transformers which are not short-circuit proof are installed, additional fuses must be fitted with ratings appropriate to the nominal current of the outgoing circuit. Single-pole protection is sufficient in this case, EREA “fuse-boxes” provide a suitable solution.Note: if cable or busbar systems are installed, it may be appropriate to fit a current-limiting device in the secondary circuit which reduces the power absorbed by the modern lamp, in order to avoid overcurrents. Dimmers cannot be used with these devices.

Dimmers:

The on-off switches (10 A/250 V, unipolar or bipolar) are fitted in the primary circuit of the transformer. The cooling of the appliance must not be impaired by insulating materialsAll transformers in the Erea range are suitable for surface mounting on a wooden surface, or for building into furnishings. The maximum temperature which the supporting surface and housing may be allowed to reach, in the event of a fault, is determined by the res-pective standards: Low-voltage halogen lighting is ideal for dimming by means of a suitable combination of upstream devices. Operation at a low voltage over a longer period may result in interference of the halogen cycle, resulting in formation of a black deposit and a reduction in the lifespan of the lamp. It is therefore advisable to operate the lamp regularly at nominal load.Selection of suitable dimmers for use in conjunction with The transformers suitable for surface mounting are installed in (false) ceilings such that operation, inspection and replacement are not impaired. They are secured to the fixed parts of the (removable) false ceiling.Only heat-resistant wire may be used for connecting the device to the lamp.The following electromagnetic transformers:• Phase control (leading edge) dimmers suitable for inductive loads .
R,L minimum clearances 20 cm must be observed if trouble-free operation is to be ensured: - Transformer to lamp: • U niversal dimmers Rem.:
R,L,C 20 cm Trailing edge dimmers are not suitable.

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