EN 50059-1990 pdf download.Specification for electrostatic hand-held spraying equipment for non-flammable material for painting and finishing.
3.3 Electrical requirements
3.3.1 Any cable to the spray gun, other than that carrying only functional extra-low voltage circuits without electrical separation shall include an earthed metallic screen protected by an insulating sheath. If this is not possible in the case of the high voltage cable due to design reasons, any other construction shall be tested in accordance with 5.6.2.
3.3.2 All the non-current carrying conductive parts of the spray gun other than those designed to acquire a high potential shall he assembled so that they remain in electrical contact with each other. These conductive parts shall be connected to the earth terminal in the power supply of the high voltage generator by means of terminals of the type described in Annex A or other connections which are equally reliable.
NOTE I A method of connection between the metal parts of the spray gun and the earth terminal in the power supply of the high voltage generator is via the metallic screen referred to in 3.3.1 above.
NOTE 2 In the case where the generator is incorporated in the spray gun, the conductive parts of the spray gun must be efficiently connected to a good earth.
3.3.3 All the electrical components of a spray gun with the exception of the high voltage electrode shall comply with the degree of protection of IP 54 as defined in HI) 365 S3.
3.3.4 The spray gun shall pass a voltage test of 1.2 U between the high voltage circuit and all parts of the spray gun which are touchable in normal operational use while spraying (this will require the suppression of corona current from the high voltage electrode, see 5.6.1).
3.3.5 The high voltage cable shall be capable of withstanding a voltage test of 1,5 Umax (see 5.6.2).
3.3.6 The operating trigger of the spray gun shall be biased towards the OFF position. The trigger, when released, shall switch off the high voltage supply and the spraying material supply to the spray gun within 2 s.
Multi outlet high voltage supplies shall not be used unless isolation for each high voltage outlet can be achieved by release of the operating switch of the spray gun connected to the outlet concerned.
3.3.7 Any current limiting resistor used in the spray gun or the associated apparatus shall be so mounted, insulated and protected that it is immune from short circuit and shall be so rated that it is undaniaged when a short circuit occurs between the high voltage electrode of the spray gun and earth for 5 mm.
3.3.8 Components on which safety in respect of high voltage electric shock depends and which are built into the high voltage supply shall be connected, assembled, etc., so that the safety of the device cannot be prejudiced.
3.3.9 If Zener diodes are used to limit the high voltage, they shall be duplicated (connected in parallel).
Zener diodes and components, except transformers, on which safety depends shall not be operated at more than 213 of their manufacturer’s rating under a one fault condition (refer also to 4.2 and 7.6 of
EN 50020).
3.3.10 Potentiometers whose adjustment could increase the maximum tested high voltage output shall not be capable of re-adjustment. rrhe locking of the adjustment shall he durable and permanent.
3.3.11 The maximum capacitance of the whole system, e.g. high voltage generator and its high voltage cable, spraying material container and its hoses insulated from earth, shall not exceed 2 000 pF, see 5.5.4.
3.3.12 The shock current to a human being from a touchable part in normal operational use of the system, shall he limited by a limiting resistance of not less than 10 k per kilovolt of Umax.
Dependent on the design of the system this resistance can be the resistance of the spraying material in the hose, or a resistor in the high voltage supply lead in the spray gun or a combination of both, see Figure 1 to Figure 9.
3.3.13 The maximum energy from the whole system available in the form of an electrical discharge to a human being from a touchable part shall not exceed 350 mJ, see also 5.5.4.
3.3.14 The total direct current continuously available from a touchable part shall not exceed 2 mA.
4 Supply of spraying material
4.1 Spraying material container
4.1.1 If the container is made of conductive material it shall be provided with a means for connecting to earth (see 4.1 in Figure 1, Figure 3 and Figure 5).
4.1.2 If the container is made of non-conducting material it shall be equipped with an earthed conductive connection. This connection shall be in contact with the spraying material (see 5.2 in Figure 2 and Figure 6 and 12.1 in Figure 4).EN 50059-1990 pdf download.
EN 50059-1990 pdf download
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