Professional competence in electrotechnics according to Act 50/1978 Coll. Workers instructed - §4 (without professional training or experience, only within laboratory training at the FBMI, not valid outside the FBMI)

Workers instructed (§4) - without requirements for professional training or experience were familiarized within the scope of their activities with the regulations for the operation of electrical devices by the organization, were instructed in this activity, were warned about the possible dangers of electrical devices, were familiarized with the giving of first aid during electrical current accidents.

The danger of electrical current accidents depends mainly on: the source voltage, the current frequency, the wave or pulse shape, the duration of the current’s passing through the organism, the current path through the body.

Symbology and signs in electrotechnics – the meaning of safety colours

Symbology and signs in electrotechnics – the safety meaning of geometric shapes

Symbology and signs in electrotechnics – safety notice examples SignSafety sign meaning SymbolSupplementary sign Notice examples Restriction Electricity use or electrical device manipulation restriction Lightning bolt 1) DO NOT SWITCH ON DO NOT SWITCH ON – WORK IN PROGRESS DO NOT SWITCH ON – THE DEVICE IS BEING WORKED ON Direction Directions for the correct operation of electrical devices Lightning bolt TURN OFF IN DANGER ! EARTH BEFORE WORK ! WarningDanger - electricity Lightning bolt WARNING – ELECTRICAL DEVICE ! WARNING – LETHAL VOLTAGE ! WARNING – LIVE DEVICE InformationSafe or release state of the device Lightning bolt EARTHED SHORTED OFF 1) ČSN IEC 417

Symbology and signs in electrotechnics – safety sign examples Restriction sign Direction sign Warning sign Information sign

What are safety signs or Help those afflicted by injuries

Symbology and signs in electrotechnics – graphical symbols on electrical devices

Symbology and signs in electrotechnics – labeling conductors with letters Conductor label English nameCzech equivalent LLine Conductorfázový vodič NNeutral conductorstřední vodič EEarthing conductoruzemňovací vodič PEProtective (+Earthing) conductorochranný vodič PENPE+N = PEN conductorvodič PEN

Alternating current nominal voltage according to the ČSN Voltage up to V Grid: three-phase with an earthed node Voltage over V Grid: three-phase with an isolated node ČSN ČSN IEC ČSN ČSN IEC / 380 V230 / 400 V3 kV 380 / 660 V400 / 660 V6 kV V 10 kV --22 kV --35 kV kV kV(400) 420 kV

Maximum allowed electric current values a steady electric current between parts that are touch accessible, flowing through 2000Ω of resistance, must never surpass 3,5mA A.C. or 10mA D.C.

Basic rules for working in ÚBMI ČVUT laboratories max. 10 students per one assistant, the assistant must check the switching device before starting class work, the assistant must supervise the correct use of protective instruments, safety signs and notices are used in the laboratory, each student has gained professional competence (§4).

Protecting electrical circuits from short-circuiting and overloading Protecting electrical circuits from short-circuiting and overloading safety fuse x circuit breaker, use only appropriate and original fuses and circuit breakers, do not repair fuses and circuit breakers, perform the replacement only with unloaded parts.

Electrical and electrotechnical device safety – protection classes

Electrical and electrotechnical device safety– extension cords (policy) two core flexible cords with a plug without an earthing contact cannot be used for connecting class I. devices, extension cords used for extending power distribution from outlets must always be triple cored, flexible cords without a protective conductor with a plug without an earthing contact for class II. appliances must have their plug inseparably connected,

Regular check-ups and reviews of electrical appliances and hand- held electric tools hand-held electric tools, appliances divided into categories, dates set according to usage, protection class and category (for appliances), the protective conductor connection is checked, the insulation resistance is measured, the line supply cables are also checked and measured, standards and recommendations exist.

Important regulations ČSN EN Medical electric instruments Part 1: General safety requirements, ČSN – 4 – 41 Electrotechnic regulations. Electric devices. Part 4: Safety. Chapter 41: Protection from electrical current accidents,

First aid during electrical current accidents FREE the afflicted person from the electric circuit in a safe and suitable manner, find out if the afflicted person is conscious, breathing, has a tangible pulse, treat any wounds, if the afflicted person isn’t breathing, then apply mouth to mouth artificial respiration, if the pulse isn’t tangible, then apply indirect heart massage (BE CAREFUL about internal injuries), possible combination of both – call a doctor, but continue with resuscitation until the doctor arrives.

First aid during electrical current accidents – clearing airways (and respiration check)

First aid during electrical current accidents – mouth to mouth artificial respiration (bending the head backwards)

First aid during electrical current accidents – mouth to mouth artificial respiration (performing)

First aid during electrical current accidents – stable position

First aid during electrical current accidents – indirect heart massage (preparation and principle)

First aid during electrical current accidents – indirect heart massage (performing)