Transcript ELECTRICAL DEVICE

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
Sign
Safety sign
meaning
Symbol
Supplementary 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 !
Warning
Danger electricity
Lightning
bolt
WARNING – ELECTRICAL DEVICE !
WARNING – LETHAL VOLTAGE !
WARNING – LIVE DEVICE
Information
Safe 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
http://ucjtk.ff.cuni.cz/publikace/12-04/tabulky.htm
Symbology and signs in
electrotechnics – graphical
symbols on electrical devices
Symbology and signs in
electrotechnics – labeling
conductors with letters
Conductor
label
English name
Czech equivalent
L
Line Conductor
fázový vodič
N
Neutral conductor
střední vodič
E
Earthing conductor
uzemňovací vodič
PE
Protective (+Earthing) conductor
ochranný vodič
PEN
PE+N = PEN conductor
vodič PEN
Alternating current nominal
voltage according to the ČSN
Voltage up to 1 000 V
Grid: three-phase with an earthed node
Voltage over 1 000 V
Grid: three-phase with an isolated node
1979
1993
1979
1993
ČSN 33 0120
ČSN IEC 38
33 0120
ČSN 33 0120
ČSN IEC 38
33 0120
220 / 380 V
230 / 400 V
3 kV
3 kV
380 / 660 V
400 / 660 V
6 kV
6 kV
1 000 V
1 000 V
10 kV
10 kV
-
-
22 kV
22 kV
-
-
35 kV
35 kV
-
-
110 kV
110 kV
-
-
400 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
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 handheld 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 60601-1 Medical electric
instruments Part 1: General safety
requirements,
ČSN 33 0000 – 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)