Výukový program: Mechanik - elektrotechnik Název programu: Základy elektrotechniky II.ročník, základní charakteristiky elektrických zařízení Vypracoval : Škarka Miloš Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/ je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.

The protection of electric devices by using the casing is a way of protection, where the electric device is protected against outer effects and against other objects intrusion and also serves as a protection against dangerous contact with animate parts. The protection using the casing is defined in the regulation ČSN EN Levels of protection are defined by the IP code followed by a number and in some cases even additional letters.

The f irst number: Expresses the level of the casing protection against a dangerous contact with animate parts, against an intrusion of other objects and expresses also resistance to dust intrusion. The summary of meanings and meaning characteristics of individual numbers are mentioned in the chart no. 1. The symbol isn‘t required by the regulation, but it is usually mentioned on electric devices for installations. IP x x 1. protection against: Dangerous contact Intrusion of other objects Dust intrusion 2.Protection against water intrusion If it wasn’t verified, than instead of the number there has to be the letter X. Ingress Protection

Chart no. 1 NumberProtection against dangerous contact Protection against other objects and dust Symbol mustn´t reach animate partsmustn´t intrude into the casing 0 unprotecte d -----unprotected Contact with a hand ball with the diameter 50 mm pushed by the power of 50 N object up to the diameter 50mm ball with the diameter 50 mm pushed by the power of 50 N Contact with a finger Probe Φ 12,5 mm with handle pushed by the power of 30 N object up to the diameter 12,5mm ball with the diameter 12,5 mm pushed by the power of 30 N ----

Chart no. 1 3 contact with a tool Probe Φ 2,5mm with handle pushed by the power of 3 N object up to the diameter 2,5mm Probe Φ 2,5mm pushed by the power of 3 N contact with a wire Probe Φ 1mm with handle pushed by the power of 1 N object up to the diameter 1mm Probe Φ 1mm pushed by the power of 3 N ⋆5⋆ contact with a wire Probe Φ 1mm with handle pushed by the power of 1 N dust with granity lower than 25µm amount jeopardizing functionality and safety of a device 6⋆6⋆ contact with a wire Probe Φ 1mm with handle pushed by the power of 1 N dust with granity lower than 25µm not at all

The second number :Expresses the casing resistance to water intrusion. The summary of meanings and meaning characteristics of individual numbers are mentioned in the chart no. 2. The symbol isn‘t required by the regulation, but it is usually mentioned on electric devices for installations.

Chart no. 2 Num ber Protection againstThe dangerous amount mustn‘t intrude while⋆) symbol 0 Unprotected water falling in drops vertically Water falling in drops from nozzles with pitch 20x20mm, water flow rate 0,4ml/min for 10 minutes 2 water falling in drops under the angle of 15° from the vertical Water falling in drops from nozzles with pitch 20x20mm, water flow rate 1,2ml/min for 2,5 minutes – in each of the 4 positions 3 raining under the angle of 60° from the vertical Splaching from nozzles with diameter 0,4mm on the swinging curve, nozzle flow rate 0,07l/minute, time period 10 minutes, or by shower with diameter 102mm with 122 nozzles with diameter 0,5mm and flow rate 10l/minute minimally for 1minute/m2 4 splashing water under the angle of 180° from the vertical Splashing from 0,2m from nozzles with diameter 0,4mm on the swinging curve, nozzle flow rate 0,07l/minute, time period 10minutes, or by shower with diameter 102mm with 122 nozzles with diameter 0,5mm and flow rate 10l/minute minimally for 5 minutes

Chart no. 2 *) Intrusion of dangerous amount means that water intrudes to insulated parts, reaches animate parts, cumulates in cable muzzles or conductor spaces. It is assessed visually, but there is measuring of the insulation state as the evaluation criterion after the test. Numb er Protection againstThe dangerous amount mustn‘t intrude while⋆)symbol 5 Splashing water from all directions Splashing with hose nozzle with diameter 6,3mm from 2,5-3meters with flow rate 100l per minute for 1minute/m2 6 intensively splashing water from all directions Splashing with hose nozzle with diameter 12,5mm from 2,5-3meters with flow rate 12,5l per minute for 1minute/m2 7 temporary flooding the object up to 0,15 m above the upper edge immersion under water surface, the upper part at least 0,15 and the bottom part at least 1 m below the water surface for 30 minutes 8 permanent immersion of the object into deep water immersion under water surface to the chosen depth and for the chosen time …bar

 The protection using the casing  What is it, that casing protects a device from?  What is it, that casing protects an operator from?  The symbol on the picture 1 and 2 ? Picture 1Picture 2

 The IP code composition  How many levels of protection using the casing do we know?  What is the minimum casing, that has to be on a device used for operations under the surface of a swimming pool?

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