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AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
► History
► Scope
► Objectives and covered
risks
► Safety general
principles
► Terminology
► The circuits
► Grade of Insulation
► Quantification of
insulation
► Heating
► Resistance to fire
► Fault conditions
► Television receivers
► Philosophy of CEI 62368-1
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
IEC 60065:1952 (ed 1.0)
1952 Safety requirements for
electric mains operated radio
receiving apparatus
IEC 60065:1965 (ed 2.0)
Safety requirements for mains
operated electronic and
1965
related equipment for domestic
and similar general use
IEC 60065:1998 (ed 6.0)
07Audio, video and similar electronic
1998 apparatus – Safety requirements
091998
ACOS = Advisory Committee On
Safety
IEC 60950:1986 (ed 1.0)
Safety of information technology
equipment including electrical
business equipment
IEC 60950:1991 (ed 2.0) +
A1:1992 + A2:1993 + A3:1995
+ A4:1996
GUIDE IEC 112:1998 (ed 1.0) by ACOS
Guide on the safety of multimedia equipment
1986
1996
IEC 60065:2001 (ed 7.0)
2001 Audio, video and similar
electronic apparatus –
Safety requirements TC92
IEC 60950-1:2001 (ed 3)
Information technology
equipment – Safety – Part
1: General requirements
TC 74
Evolution of apparatus functionalities
High density of electronic components ==>
Increase and mixing of functionalities
TC 108
2005
2010
2013
= (TC92
+ TC 74)
IEC 60065:2001
+A1:2005
TC108
IEC 60950-1:2005
TC108
CEI 62368-1 :2010
TC108
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Electronics apparatus for
» reception, generation, recording
» Record and reproduction of audio, video and
associated signals
» Combination of the above apparatus
Household and similar general use
Places of public assembly
» School, theatres,
» Workplace
Supplied by:
»
»
»
»
Mains
External power supply module
Battery
Remote power feeding
At a rated voltage of
» 250 V (single phase) or
» 433 V (other than single phase)
May be connected to telecommunication
network or Cable distribution network of
antenna signal
Sound and /or image receiver and amplifier
(radio, television set, Citizen Band radio etc..);
Supply apparatus intended to supply other
apparatus in this standard scope;
Audio and/or video educational apparatus
(record player, tape reader, tape walkman and video player,
etc..);
Multimedia apparatus;
Beamer;
Video recorder and associated
monitors (camera, camcorder, etc..) ;
Electronic gaming and scoring machines;
Juke boxes;
Electronic light effect apparatus;
cable head-end receivers;
Antenna signal converters and amplifiers;
Antenna positioners;
Alarm systems apparatus;
Record and optical disc players;
Professional sound/video systems;
Electronic flash apparatus for photographic
purposes;
Etc…
Film, slide and overhead projectors
» IEC 60335-2-56
gaming and scoring machines for
commercial use
» IEC 60335-2-82
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Standard requirements allow
A protection against:
Hazardous current through human body
(electrical choc)
Excessive temperature value
Fire ignition and propagation
Mechanical instability
Injury from mechanical parts
Hazardous radiations
Implosion and explosion effects
Design of a reliable apparatus
Current flow through human body
Observed physiological effects
depend on:
»
Intensity of the current
Applied voltage and frequency
Body impedance (contact surface,
humidity)
»
Duration of the passage
»
Current path in the body
High intensity : directs effects
»
»
Burning
Ventricular fibrillation
Low intensity : involuntary reaction
»
»
»
Downfall
Injury
Etc.…
Direct contact in normal condition
»
Parts at hazardous voltage
Insulation failure;
in fault condition
»
»
Rupture of the electric envelope
Contact current
Short-circuit between high current energy
source connectors
»
»
»
Arcing
Emission of molten metal
Burning
Possible risks with low voltage circuits
»
Battery
Excessive heating
»
»
In normal use
In single fault situation
• Overload,
• Insulation failure
Ignition, fire
»
»
Releasing of connection
Inflammation of liquid
Instability
»
»
On inclined plane
In full deployment situation
Sharp edges and corners
Moving parts
Projection of particles
»
»
Implosion of cathode ray tube (CRT)
Explosion of battery
Radiations
Lasers and LED
Sound frequencies
Radio frequencies
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Safety integration
Remove
or lower
the risk at
the design
phase
Protect
for risks
which cannot
be removed at
the design
phase
Inform the user
about the
residual risks
Marking/Training
Goal: cancel all risk during the foreseeable
life time of the apparatus : transportation,
installation, usage, shutdown and disposal
Avoid risks
in normal operation conditions
but also:
In fault condition
In foreseeable unexpected usage
Under external environmental
influences (temperature, humidity,
altitude, pollution, overvoltage etc…)
Choose material and components
in such a way that they can:
Operate without being hazard source,
during the apparatus life time
Be compatible with the other components
Operate correctly in their ratings
Avoid hazard in single fault condition
Identify type of circuits in the apparatus
(Primary, Secondary, Low voltage, Extra-low voltage, Safety
Extra low voltage, current limited , Telecommunication network
voltage, cable distribution of antenna signal).
Determine insulation between:
- circuits taken by pairs,
- each circuit and accessible
part
(basic, supplementary, double, reinforced)
Verify conformity to standard
requirements (creepage distance, clearance,
solid insulation, dielectric strength )
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Mains
» power source with voltage > 35 V (peak) a.c. or d.c.
Rated voltage; rated current consumption; rated
power consumption; rated frequency;
» Values in normal operating condition
» Expected to be marked on the apparatus
» As an alternative, rated current consumption and
rated power consumption may be given in the
instruction manual.
» “/” for user selectable ratings (120/240 V)
» “-” for rating range (120-240 V)
Tolerance = +10%, -10%
Class I
» Basic insulation + earth connection of conductive
accessible parts
Class II
» Double insulation or reinforced insulation
Class III: Not defined in IEC 60065
Defined in IEC 60950-1 and CEI 62368-1
» Apparatus supplied by a SELV circuit or Energy
Source class 1 (ES1)
and
» No internal hazardous voltage or Energy Source
class 3 (ES3)
Direct connection to the mains
Mains
fuse
≥9A
Apparatus
Conductive connection to the mains
Mains
2000 Ω
≥ 0,7
mA
Apparatus
Permanently connected apparatus
» Needs a tool
» Cannot be loosened by hand
Remote power feeding
» supply of power to apparatus via a
cable network (e.g.: Telecommunication)
Pluggable equipment Type A
» connection to a mains supply via a non-industrial
plug and socket-outlet or a non-industrial appliance
coupler, or both
Pluggable equipment Type B
» connection to a mains supply via a industrial plug
and socket-outlet or an appliance coupler, or both,
complying with IEC 60309
Protective earthing terminal
» TERMINAL to which parts are connected and which
is required to be connected to earth for safety
reasons
Enclosure
» housing affording the type and degree of protection
suitable for the intended application
Safeguard
against the
spread of fire
from inside to
outside of the
product
Safeguard against
mechanically-caused
injury
Safeguard against
electrically-caused
injury
Minimize the
spread of fire or
flames from
within
Reduce the risk of
injury due to
mechanical and other
physical hazards
Limit access to parts
that may be at
hazardous voltage or
Hazardous energy level
Mechanical
enclosure
Electrical
enclosure
Fire
enclosure
The enclosure may be only for one
protection
The same enclosure can provide all the
three protections.
Decorative enclosure
» Is outside the mechanical enclosure of the
apparatus
» Has no safeguard function
Noise signal
» random signal having normal probability distribution
of instantaneous values.
Pink noise
» Energy per unit bandwidth inverse, proportional to
frequency
Rated load impedance
» Output circuit load specified by the
manufacturer (4 Ω, 2x8 Ω, 32 Ω etc..)
Source transducer
» Convert the energy of a non electrical signal to
electrical energy
Load transducer
» convert the energy of an electrical signal into
another form of energy
Non-clipped output power
» 1000 Hz sine-wave power dissipated at the onset
of clipping on either one, or both peaks.
Pollution degree 1
» No pollution or dry pollution, non-conductive,
Pollution degree 2
» Normal, non-conductive, possibility of temporary
conductivity due to condensation
Pollution degree 3
» Conductive pollution area, or non-conductive
pollution which could become conductive due
» to expected condensation
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Primary
Secondary
Hazardous live voltage
Hazardous energy
Low Voltage
Extra Low Voltage
Safety Extra Low Voltage
Limited current
Telecommunication network
Cable distribution network
Primary circuit: conductively connected to the
mains; may content the following components:
»
»
»
»
»
»
»
»
Cables
Primary winding of transformer
Filters components (mainly for EMC reasons)
Motors
Relay
Fan
Fuse
Etc.…
Secondary circuit: not conductively connected
to the mains
»
»
Separated from primary circuit
Supplied by isolation means: transformer,
converter etc…
Hazardous live voltage
»
»
»
> 35 V peak or 60 V d.c.
> 120 V rms for professional audio apparatus signal
> 71 V rms. for non professional audio apparatus signal
Hazardous energy
»
»
Stored charge > 45 µC for charging voltage U:
60 V < U ≤ 15kV peak or d.c.
For charging voltage U > 15 kV peak or d.c., then
discharged energy > 350 mJ
Extra Low Voltage (ELV)
»
»
≤ 35 V peak or ≤ 60 V d.c. in normal condition
Hazardous voltage in single fault condition
Safety Extra Low Voltage (SELV)
» ≤ 35 V peak or ≤ 60 V d.c. in normal condition
» ≤ 70 V peak or ≤ 120 V d.c. in single fault
condition
» Separated from hazardous voltage by 3 methods
•
•
•
M1: double insulation or reinforced insulation
M2: basic insulation with screen connected to the earth
M3: basic insulation with secondary circuit connected
to the earth
» Separated from TNV2 and TNV3 circuit
by basic insulation
Current limited circuits: by construction, the
current never become dangerous, regardless the voltage
level.
» IEC 60065: current (using measuring network), between
any part of the circuit and accessible part (Touch
Current)
» IEC 60950-1: current (measured through non inductive
2000 Ohms load or using measuring network) between:
any two parts of the circuit,
any part of the circuit and earth
any part of the circuit and accessible part
Current limited circuits: measuring network
Current limits and measured values in normal
conditions
0,7 mA peak for sinusoidal or mixed signals U2 = 0,35 V peak a.c.
2 mA d.c.
U1 = 1 V d.c.
70 mA peak for frequency >100kHz
U1 = 35 V peak a.c.
! Under tropical climate, current limits
are multiplied by 2
Current limited circuits measuring network
Current limits and measured values under single
fault
2,8 mA peak for sinusoidal or mixed signals U2 = 1,4 V peak a.c.
8 mA d.c.
U1 = 4 V d.c.
140 mA peak for frequency >100kHz
U1 = 70 V peak a.c.
Leakage current: equivalent
to « Touch Current »
in the protective earthing connection
Telecommunication network
» Metallic wire ended transmission means for
communication between two apparatus
» May be submitted to atmospheric overvoltage
Telecommunication Network Voltage circuit
(TNV)
»
»
»
»
Located inside the apparatus
Not conductively connected to the mains
Has limited accessible surface
Voltage level limited in normal and in single fault
conditions
» 4 types: TNV0, TNV1, TNV2 et TNV3
TNV0 and TNV1 limits same SELV
SELV < (TNV2 and or TNV3) < TNV limits
TNV limits
Summary table for TNV circuits
TNV-3
TNV-3
PABX
TNV-1
Analogic
interface
TNV-2
TNV-0
PABX
digital
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Insulation
» Conceptual separation between two circuits or
between a circuit and an accessible part.
» Basic, supplementary, double or reinforced (electrical
choc protection).
» Functional
Special case of functional insulation
» Not provides protection against electrical choc
» Can be used to lower ignition risk (between SELV
and protective Earth)
» Can be used for EMC reasons (Electro-Magnetic
Compatibility )
Insulation
Level of
protection
F
B
S
D
R
E (earth)
0
1
1
2
2
1
Suitable protection
against electrical choc
=
Basic
+
Supplementary
=
Basic
+
Earth connection
=
Double
=
Reinforced
PRINCIPLE: always 2 levels of protection
Example
Metallic enclosure connected to earth
B ou S
Primary
Mains connection
F
D
B
TNV
SELV
R
Hazardous
voltage
B
Outlet
S/R
SELV
Telecommunication lines
Current limited
B
Data output connector: RS232...
Exercise (To find circuit type and insulation grade)
1000 V d.c;
mA
85 V
120 V a.c.
Connection to the mains
Metallic enclosure
+ 18 V
1
+5V
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Creepage distance (CR)
» Shortest distance between two conductive parts,
measured on the surface of the insulating material
Clearance (CL)
» Shortest distance between two conductive parts,
measured in the air
See Annex E of IEC 60065:2011 for all possible situations
Distance through the isolation
» Thickness of solid insulation
Insulation resistance
» Measurement on any insulation type
Dielectric strength
»
»
»
»
On any insulation type
On thin sheet materials
May be required in addition to CR and CL.
On any insulation as validation test after
environmental treatment (heating, cooling,
humidity, vibration, choc etc…)
Creepage distance
Tables 8, 9, 10 et 12
» Supply voltage
» Pollution degree
» Grade of insulation
» Working voltage
» Overvoltage category
» Material group and
comparative tracking
index
Clearance:
Tables 11 et 12
» Supply voltage
» Pollution degree
» Grade of insulation
» Overvoltage category
» Working voltage
Distance through insulation: §8.8
» Grade of insulation
Insulation resistance: Table 5
» Grade of insulation
Dielectric strength: Table 5
» Supply voltage
» Working voltage
» Grade of insulation
Working voltage: Maximum voltage value between
2 circuits separated by an insulation (expressed in rms,
peak or d.c.)
» Value including non-periodic superimposed pulses
with a half-value time longer than 50 ns
» Unearthed accessible conductive parts shall be
assumed to be connected to an earth terminal
» Floating circuit assumed to be connected to an
earth terminal at the point which results in the
highest working voltage being obtained;
» Double insulation: short-circuit across on of the
insulation when measuring the second
one and vice versa.
Working voltage:
» Between two transformer windings:
TS = highest voltage between any two ends of
the windings
» Between transformer winding and other parts of
the apparatus:
TS = highest voltage between any end of
the winding and the other part
Overvoltage category: Define the level of
overvoltage on the mains according to 4 identified areas
IV: Outdoor power lines
and cables
III: Building installation
II: Equipments, apparatus
IV
III
II
I
I: parts of apparatus
connected to secondary
circuit
Table from IEC 60950-1
Material group:
characterisation of resistance
against spread of arching on insulation material surface
» CTI = Comparative Tracking Index
» 4 groups
I
II
IIIa
IIIb
600
400
175
100
≤
≤
≤
≤
CTI
CTI < 600
CTI< 400
CTI < 175
» If CTI not known, group IIIb is used.
Thin sheet material : no insulation thickness
required if:
» Basic and supplementary insulation
2 layers of sheet material, each withstand the
dielectric strength test
3 layers of sheet material with any 2 by 2
combination withstand the dielectric strength
test
» Reinforced insulation
2 layers of sheet material withstand the
dielectric strength test
3 layers of sheet material with any 2 by 2
combination withstand the dielectric
strength test
Thin sheet material :
Dielectric strength test instrument
Printed board
» CR and CL between 2 conductors, one may be
conductively connected to the mains : Figure 10
d
lacquer = ignored
d
» type B coated printed board (type 2) shall comply
with the requirements of IEC 60664-3
Jointed insulation
» Uncemented joints: normal CR et CL
» Cemented joints : no CR et CL; but
3 samples submitted to 10 times the following
thermal cycling test
•
•
•
•
68 h at (X ± 2)°C
1 h at (25 ± 2)°C
2 h at (0 ± 2)°C
1 h at (25 ± 2)°C
X= (Max temperature
max during heating test
+ 10K), with minimum
85°C
1 sample submitted to dielectric strength with
test level x 1,6 and after humidity treatment
2 samples submitted to dielectric strength with
test level x 1,6 without humidity treatment
No insulation breakdown
Enclosed and sealed parts (§13.7)
»Not directly connected to the mains
»CR and CL in Table 12
3 samples submitted to 10 times thermal
cycling test
• 68 h at (X ± 2)°C
• 1 h at (25 ± 2)°C
• 2 h at (0 ± 2)°C
• 1 h at (25 ± 2)°C
X= (Max temperature max during heating test + 10K), with minimum
85°C
Dielectric strength test
No failure allowed.
Enclosed, filled and sealed parts (§13.8)
Insulating compound fills all internal void spaces
» No CR and CL; but
» 3 samples submitted to 10 times thermal cycling
test as above.
» Dielectric strength test
» After test, visual verification:
no cracks in the encapsulating, impregnating or
other material,
coatings not loosened or shrunk
no significant voids in the material after
sectioning the component
Insulation resistance
» Measured with 500 V d.c.
Dielectric strength
» Direct current voltage or alternative current
voltage at mains frequency
» The measurement equipment shall be able to
source 200mA when its output is short-circuited
» Internal overcurrent limited to 100 mA during test
» Application of half of the maximum test voltage,
increase quickly the voltage level to the maximum
value and maintain it for 1 minute.
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Test conditions
» Maximum load configuration
» Apparatus positioned in accordance with the
»
»
»
»
instructions for use
If position not specified, 5 cm behind the front
edge of an open-fronted wooden test box with 1
cm free space along the sides and top and 5 cm
depth behind the apparatus
Apparatus supplied at maximum ranges of rated
supply voltages with tolerance values added
Measurement after thermal stability (in general
after 4 hours of operating)
Test environment air shall be quiet and
not
ventilated
Measurement method
» By thermocouples (refer to IECEE document
reference CTL-OP 108)
» By resistor variation
Motor
Transformer
Inductance
Not used for switching mode power supply
transformer
Permissible temperature rise: tableau 3
Maximum values in single fault condition
Permissible value can be exceeded in the following
situations:
» Short-circuit of insulation which withstand
dielectric strength test
» Short-circuit or disconnection of a component in
conformity of requirements of the standard clause
14
Maximum values in single fault condition
Permissible value can be exceeded in the following
situation:
» operation of replaceable or resettable protective
devices
°C
Heating test
2 min
Permissible
Temperature
rise
t
Heating test
Heating test
t
Heating test
1 min
Measurement of dielectric strength
Maximum values in single fault condition
Permissible values can be exceeded:
» on printed circuit board: by 100K for 5min
» for class V-0 printed circuit board on one or more
small surfaces with total value no more than 2
mm2 in case of no electrical choc.
Conductors can be interrupted, peeled or loosened
during the test providing that:
» The printed board is classified V-0
» The interruption is not a potential fire source
» CL and Cr are not reduced
» Protective earthing connection
is maintained
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Objective: Prevent
» Ignition
(Potential ignition source : V > 50 V d.c. or peak and
P > 15 VA)
» Spread of fire
Solutions
» Good design practice in order to prevent potential
ignition sources
Thermal cut-out
Electronic circuit for protection (IC current
limiter)
» Choice of appropriate components
Flammability categories as per IEC 60695-11-10
Their position in the apparatus
» Implementation of fire enclosure
Flammability categories
» From HB, outer decorative part, to 5V metallic
enclosure
» Wood and wood-based material of thickness > 6
mm === V-1
HB
V-2
V-1
V-0
5V
No Flammability class required
Ventilation
opening
< 1 mm
Envelop > V-0
-
components
Metallic parts < 4g
Small electrical components
Printed board V-1
Capacitors volume < 1750 mm3
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Implementation conditions
» Apparatus in normal working situation
» Only one single fault each time
» Multiple faults can result from the applied
single fault
» Possibility of non operation of the apparatus
after the fault test
Which fault to simulate?
» Open and short-circuit
» Overload of the output of linear or switch mode power
supply transformer
» Continuous dissipation of apparatus designed for noncontinuous dissipation
» Excessive dissipation of integrated circuit
» Isolation breakdown between primary circuit and any
accessible parts:
conductive accessible parts
earthed metallic screen
SELV
Limited current circuit
Which fault to simulate?
» Unexpected impedance value loaded on power output
»
»
»
»
»
terminal
Short-circuit of protection components (thermostats,
temperature limiter) or of component bridging these
protections if the apparatus is used without
surveillance
Opening of component in regulation circuit loop
Overload of motors (blocked rotor)
neutralisation des timers
simulation of cooling liquid leakage
Evaluation during fault conditions
» No excessive heating
» No hazardous voltage or energy on accessible parts
» No loosening of protective earth connection
» Moving parts shall not become dangerous
» In case of ignition, no spread of fire outside of the
enclosure (flame shall stop in less than 10 s)
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
Surge test (§10.1)
» Between :
TERMINALS for the connection of antenna
AND
MAINS supply TERMINALS
» Between
MAINS supply TERMINALS
AND
any other TERMINAL of apparatus providing supply
to antenna apparatus
» 50 discharges at a maximum rate of 12/min, from a
capacitor of 1 nF charged to 10 kV (tested apparatus is
not supplied)
» Expected result: dielectric strength test OK
Surge test (§10.1)
Test circuit
Surge test (§10.1)
Example of
switch S
Antenna coaxial sockets (§12.5)
» 3 tests in the following order:
Endurance: 100 insertion and withdrawal
Impact: 3 spring-operated hammer impact of 0,5 J
Torque: 10 times 50 N force applied during 10 s
» Followed by a dielectric strength test
» No damage in the sense of this standard:
No access to hazardous voltage
No damage to any isolation
Antenna coaxial sockets
Test plug for
endurance test and
its dimensions
Mechanical strength of picture tubes(§18)
» Protective film required if maximum face dimension >
16 cm
» Intrinsically protected tubes: IEC 61965 tested
» No Intrinsically protected tubes : implosion test
Scratch on the side or on the face of the tube
Repeatedly cooling with liquid nitrogen (-273°C + 77
K = -196 °C) up to fracture
» Expected result:
No particle exceeding 2 g shall have passed a 25
cm high barrier, placed 50 cm from the tube
No particle, regardless its size, shall have
passed a similar barrier at 2 m.
Mechanical strength of glass (§19.5)
» Excluded: picture tubes; laminated glass with surface
area > 0,1 m2 or major dimension > 450 mm
» Test: 3 shocks of 0,5 J using impact hammer
» If the glass breaks or cracks: fragmentation test §19.5.1
» Expected result:
number of particles counted in a square of 50 mm >
45
or no loose of particles in the square (particles are
kept together)
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS
PRINCIPLE
1- Pain, injury or property damage occurs during
transfer of energy from an energy source to a
body part or to property
2- Safety = interposition of safeguard in order to
reduce the likelihood of the transfer of the energy
and/or the hazard level
Energy
source
Energy
transfer
Three block model for pain and injury
Body
part
Three blocks model for safety
Energy
source
Safeguard
Body
Models for protection against fire
Energy
source
Safeguard
Energy
source
Fuel
material
Fuel
material
Safeguard
Equipment safeguard
»
»
»
»
basic
supplementary
double
reinforced
Installation safeguard
»
supplementary
•
•
Specified by the manufacturer
Implementation not controlled by the manufacturer
Personal safeguard
»
»
»
basic
supplementary
reinforced
Instructional safeguards
»
»
»
basic
supplementary
reinforced
Precautionary safeguard
»
»
for class 2 Energy Source
provided by skilled person to instructed
person
•
•
•
training
experiences
supervision
Skilled safeguards
»
»
»
for class 2 and class 3 Energy Source
supplementary
related to skilled person
Identify and classify the Energy
Source for each type of hazard
(SE1, SE2, SE3).
Require the appropriate Protection
for each Energy Source
(basic, supplementary, double , reinforced)
Verify conformity to
standard requirement
AFSEC
Certification Officer 26/27-08-2013
NAIROBI
Jean LANZO
IEC SYSTEM OF CONFORMITY ASSESSMENT
SCHEMES FOR ELECTROTECHNICAL
EQUIPMENT AND COMPONENTS