1. Prisma Plus the tested switchboard, complying with standard IEC 60 439-1

2. Contents The low voltage electrical switchboard
The functions of an electrical switchboard
The IEC standard
Prisma Plus : a structured switchboard based on functional units
Forms: partitioning
Forms : separations within an assembly
The minimum requirements to guarantee the safety of a LV switchboard
The tests of standard IEC
7 type tests performed by the manufacturer
3 routine tests performed by the panelbuilder
Switchboard builders and manufacturer, together for the safety challenge IEC
Prisma Plus and the IEC standard : an international influence

3. The low voltage switchboard
A vital link for electrical distribution
To satisfy the increasing needs of safety of people and equipment and availability of electrical power : its realization is not improvised…
Safety
Reliability
Availability
Maintenability
and to provide a continual balance between:
the needs of safety and availability
and the constraints of reliability and maintenability of the installation.
Definitions
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4. The low voltage electrical switchboard
Definitions
The safety is the aptitude of a system not to put the people in danger .
Availibilty is the percentage of time during which the system functions correctly. MTBF (Mean Time Between Failure) average time between two failures of a reparable system is a means of characterizing the availibility.
Reliability is the aptitude of a system to function correctly as long as possible. MTTF (Mean Time To Failure) average time of good working before the first failure is a means of characterizing the reliability.
Maintainability is the aptitude of a system for being repaired quickly.La maintenabilité est l'aptitude d'un système à être réparé rapidement. MTTR (Mean Time To Repair) the average duration of repair is a means of characterizing maintainability.
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5. The functions of an electrical switchboard
To group and protect against external influences the protection and control devices and all their electrical and mechanical connections.
To inform the end-user on the state of his installation
To protect the switchboard user against the risk of accidents (direct and indirect contact).
To evolve with the activity.
Definitions
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Wall-mount and floor standing enclosures up to 630 A
Cubicles up to 3200 A

6. The functions of an electrical switchboard
Definitions
Some of the components or specificities of the switchboard realize and/or guarantee its finalities,
in functional term :
The architecture of LV network in centralized distribution :
It results in a cutting into various switchboard, wall-mount enclosures... Distributed geographically, which
carry out the installation drawing.
Then various areas are defined within the switchboard :
equipment
busbar
connection
auxiliary
The distances from minimal insulation and safety must already be respected.
The functional units :
allow to realize the electrical functions correspondint to the user ’s
each unit is intended to cover a function, for example :
- the incoming of current in the switchboard
- the protection of a feeder or a feeders whole - the motor control...
The enclosure :
It materializes electric volume and ensures simultaneously:
the protection of electrical materials which it contains against the external influences
the protection of people against electrical shocks (direct and indirect contacts).
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7. The IEC standard
The IEC standard gives general rules for switchboards construction to meet with safety and availability needs required by the application
guarantees the minimum level of safety of people and equipment
concerns the low-voltage switchgear and controlgear assemblies for the power distribution and control.
states :
- the service conditions (temperature...)
- the construction requirements (IP, IK, forms,...)
- the tests requirements
So conformity to the standard is, for the end user, an insurance on switchboard realization quality.
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8. Prisma Plus : a structured switchboard based on functional units
This modular design brings much clearness to the switchboard :
incoming unit
current distribution units
feeder units
distribution units
connection units
communication units
Definitions
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9. IEC 60439-1 Standard and Prisma Plus : a structured switchboard based on functional units
Definitions
Incoming units : incoming circuit breaker (Masterpact, Compact NS, Interpact INS...).
Current distribution units : busbars (Linergy, flat bars, Powerclip...).
Feeder units : feeders circuit-breaker and contactors (Compact NS, Interpact INS, switch INV, modulars devices...).
Each device is part of a functional unit comprising:
a dedicated mounting plate for device installation
a front plate to block direct access to live parts
prefabricated busbar connections
systems for on-site connections
running of cables and auxiliary wires
Connection units : insulated flexible bars, prefabricated junction
Distribution units : distribution block (Polypact, Polybloc, Multiclip, terminal block...).
Communication units : measurement devices, BP, Powerlogic, Digipact (Human/swichboard Interface).
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10. Forms: partitioning
In most installations, Prisma Plus cubicles do not require partitioning, Schneider Electric offering options and features that go well beyond the recommendations of the standard :
front plates requiring a tool to be removed
doors providing access to live parts are keylocked
systematic installation of terminal shields on Compact NS circuit breakers and Interpact INS and INV switch-disconnectors
upstream and downstream terminals on the incoming device are covered
The protection of people and equipment is ensured on origin
However, Prisma Plus offers different levels of partitioning to create separations inside the cubicles and thus create Form 2,3 and 4, as defined by the standard.
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11. Forms : separations within an assembly
Prisma Plus
Form 1
Form 2a
Form 3a
Form 4a
Prisma Plus
Prisma Plus
Prisma Plus
Definitions
Form 2b
Form 3b
Form 4b
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12. Forms : separations within an assembly
Definitions
Form 1 : no separation within the enclosure.
Form 2a : the functional units are separated from busbars, but not the terminals
Form 2b : the functional units and terminals are separated from the busbars. The terminals are not separated from each other.
Form 3a : the functional units are separated from each other and from the busbars , but not the terminals.
Form 3b : the functional units are separated from each other and from the busbars. Terminals are separated from busbars, but are not separated from each other
Form 4a : the functional units are separated from each other and from the busbars . Terminals which are in the same compartment as the associated functional unit are separated from each other
Form 4b : the functional units are separated from each other and from the busbars. Terminals are separated from each other and from the functional units.
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13. The minimum requirements to guarantee the reliability of a LV switchboard
First of all, it must comply with standards :
Switchboard construction standard :
IEC : low voltage switchgear assemblies.
Structural standards for incorporated switchgear :
IEC : general provisions
IEC /3 : circuit-breakers/switches
IEC : low voltage fuses.
Installation standards :
IEC : buildings electrical installation
specific standards and rules to each country.
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14. The tests of standard IEC 60439-1
They guarantee that the switchboard complies with standard and confirm its characteristics:
7 type tests :
n°1 - temperature rise limits
n°2 - dielectric properties
n°3 - short-circuit withstand
n°4 - protective circuit effectiveness
n°5 - clearances and creepage distances
n°6 - mechanical operation
n°7 - degree of protection
3 routine tests :
n°8 - overall inspection : cabling, electrical operation
n°9 - insulation/dielectric test
n°10 - protection measures .
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15. 7 type tests performed by the manufacturer
The aim of these tests is to confirm the switchboard characteristics.
The 7 type tests are carried out on most difficult and unfavourable system Prisma Plus configurations. The assembled and cabled switchboards are made up of their usual components, connection system…, equipped with Merlin Gerin and Telemecanique switchgear and assemblied and installed according to inductrial standards
The tests are conducted either in approved laboratories (Asefa, Kema, Lcie,…), or in Schneider Electric ones
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16. Test n°1 (8-2-1) :Temperature rise limits
Guarantees the safety and reliability of the switchboard, by avoiding problems such as :
connection damages
reduction in insulation performances
risk of burn for maintenance operators
electronic components damages
faulty operation of the devices : inopportune release
Conditions
Results
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17. Test n°1 (8-2-1) :Temperature rise limits
Conditions
Tests progress:
several switchboard configurations
equipped with Merlin Gerin and Telemecanique switchgear
+10 °C< ambient air temperature<+40 °C
switchgear loaded to its rated current, multiplied by the rated diversity factor
Complying limits (temperature rise limits) :
when the temperature has stabilised, the temperature rise should not exceed limits admitted by materials or cause any burn :
70 °C for terminal for external insulated conductors
15 °C or 25 °C , according to material type , for manual operating means
30 °C or 40 °C for accessible external enclosures and covers
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18. Test n°1 (8-2-1) :Temperature rise limits
Results
The tests conducted with Prisma Plus have recorded temperature rises less than or equal to those stipulated by the standard.
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19. Test n°2 (8-2-2) : dielectric properties
Guarantees the switchboard safety and reliability , to avoid problems such as :
electrical arc generation
insulation performance decreasing
connection damages
Conditions
Results
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20. Test n°2 (8-2-2) : dielectric properties
Conditions
Tests progress :
the test voltage is applied between all live parts and interconnected exposed conductive parts (frame), as well as between each pole and all the other connected poles
dielectric test voltage :
V for a rated insulation voltage = 1000 V for busbars in cubicle and rear busbars in enclosures
- 750 V for a rated insulation voltage = 3000 V according to the type of busbars in enclosure
- 500 V for a rated insulation voltage = 2500 V according to the type of busbars in enclosure
test duration :1 minute.
Complying limits :
No arc flash-over or insulator perforation are observed.
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21. Test n°2 (8-2-2) : dielectric properties
Results
No arc flashover or insulator perforation for the test voltage following the rated voltage of busbars
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22. Test n°3 (8-2-3) : short-circuit withstand
This test simulates an incident which could occur on site
Withstanding the short-circuit currents is :
to avoid danger (rupture and projections of components, arc generation and propagation outside the switchboard,...)
it also means the installation can be quickly put back into operation after the incident
Conditions
Results
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23. Test n°3 (8-2-3) : short-circuit withstand
Conditions
Tests progress :
the short-circuit tests are carried out by using bolted connections at the ends of the main or secondary busbars :
25 kA rms/1 sec. for Prisma Plus System G
85 kA rms/1 sec. for Prisma Plus System P
Complying limits :
the main conductors and the insulating parts must retain their insulation and mechanical withstand characteristics (lenght, cross-section, dielectric properties,…).
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24. Test n°3 (8-2-3) : short-circuit withstand
Results
After a short-circuit test, the Prisma Plus main conductors and the insulating parts keep on their insulation and mechanical withstand characteristics
maximum rated short-time currents on busbars :
Prisma Plus System G : Icw 25 kA rms/1 s
Prisma Plus System P : Icw 85 kA rms/1 s.
the installation can be quickly put back into operation after a simple inspection
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25. Test n°4 (8-2-4) : effectiveness of the protective circuit
The effectiveness of the protective circuit is verified by two tests :
resistance measurement of the connection between the exposed conductive parts and the protective circuits
short-circuit withstand performed between the protective conductor and the nearest phase conductor.
Conditions
Results
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26. Test n°4 (8-2-4) : effectiveness of the protective circuit
Conditions
Tests progress :
the short-circuit tests are carried out by using bolted connections at the ends of the main or secondary busbars :
15 kA rms/1sec. for Prisma Plus System G
51 kA rms/1sec. for Prisma Plus System P.
Complying limits :
the main conductors and the insulating parts must retain their insulation and mechanical withstand characteristics (lenght, cross-section, dielectric properties,…).
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27. Test n°4 (8-2-4) : effectiveness of the protective circuit
Results
After the test, continuity and short-circuit withstand of the protective circuit, whether it consists of a separate conductor or frame, is not significantly impaired
Continuity and short-circuit withstand of the Prisma Plus protective circuit comply with the standard.
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28. Test n°5 (8-2-5) : clearance and creepage distances
Clearance control : shortest distance between two conductive parts.
Creepage distance control : shortest distance along the surface of an insulating material between two conductive parts.
Conditions
Results
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29. Test n°5 (8-2-5) : clearance and creepage distances
Conditions
The values given in the standard apply to bare live conductors and the switchgear.
The minimum clearance in air depends on the rated impulse withstand voltage and the degree of pollution in the switchboard.
The minimum creepage distance depends on the rated insulation voltage, the degree of pollution and the insulating material group separating live parts.
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30. Test n°5 (8-2-5) : clearance and creepage distances
Results
The tests carried out on typical Prisma Plus configurations, equipped with standard main busbars, validate compliance with minimum clearances and creepage distances for a voltage of 1000V, degree of pollotion 3, IIIa material group. :
minimum clearance : 14 mm
minimum creepage distance : 16 mm.
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31. Test n°6 (8-2-6) : mechanical operation
Endurance of material, guaranteeing the longevity of the various mechanisms.
Conditions
Results
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32. Test n°6 (8-2-6) : mechanical operation
Conditions
The mechanical operation test is carried out on an assemblied switchboard.
The standard requires that 50 operating cycles be carried out.
Verification of locking mechanisms are included in this range of tests.
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33. Test n°6 (8-2-6) : mechanical operation
Results
After 50 operating cycles, the interlocking mechanisms and other moving parts of the switchboard preserve their initial properties: - operation, - operating force.
Some more solicited moving parts of Prisma Plus have passed until operating cycles (door handles, hinges…).
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34. Test n°7 (8-2-7) : degree of protection
The tests carried out define the capacity of an equipped switchboard to :
protect persons against contact with live parts
protect equipment against penetration of solid objects and liquids
protect equipment against external influences such as impacts (shocks).
Conditions
Results
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35. Test n°7 (8-2-7) : degree of protection
Conditions
Tests for solid objects penetration (test finger, stem and wire).
Tests for water ingress (jets of water, drop vaps).
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36. Test n°7 (8-2-7) : degree of protection
Results
Results of tests confirm the characteristics of Prisma Plus switchboard: IP30 to IP55 and IK7 to IK10 according to the different configurations.
Prisma Plus system P : - IP30/31/55 - IK07 with fixed panelling frame - IK08 with door IP30 - IK10 with door IP55.
Prisma Plus system G :
enclosure : - IP30/31/43 - IK07 without door - IK08 with door
IP55 enclosure : IK10
Pack enclosure: - IP30 - IK07 without door - IK08 with door.
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37. The IP degrees of protection : (IEC 60529/EN 60529)
1st digit:
protection of persons
protection against solids.
2nd digit :
protection against liquids.
Additional letter (optional) : protection of persons against contact with live parts
A : protect againts access of the back of the hand
B : protect against access of fingers Ø 12 mm
C : protect against access of a tool diameter 2.5 mm
D : protect against access of a tool diameter 0.1 mm
Definitions
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38. Degree of protection Definitions
The IEC standard (02/ 2001) gives , by the IP code, the different degrees of protection provided by an electrical enclosure.
The IP code is described by 2 specific digits; an additional letter , in option, can complete the IP code when the real protection of persons against contact with live parts is better than the protection given by the first digit:
the 1st digit gives the level of protection of equipment against penetration of solid objects and protection of persons
the 2nd digit gives the level of protection of equipment against penetration of liquids.
Additional letter :
it is used only when the effective protection of persons is better than the one given bythe first IP digit
in case of only protection of persons is needed, the 2 IP digits are replaced by x.
Example : IPxxB.
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39. Degree of protection : IK (IEC 62262)
IK code : 2 digits giving the level of shock energy, in Joules :
IK 01 : 0,14
IK 02 : 0,2
IK 03 : 0,35
IK 04 : 0,5
IK 05 : 0,7
IK 06 : 1
IK 07 : 2
IK 08 : 5
IK 09 : 10
IK 10 : 20.
The IEC standard defines a IK code which gives the equipment capacity to resist to mechanical impacts , on all the enclosure surfaces.
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40. 3 routine tests performed by the panelbuilder
The 3 routine tests, easily and rapidly performed, must be carried out by the panelbuilder. :
overall inspection according to the mounting instructions and technical documents (right device ratings, tightening torques)
insulation checking by a dielectric test
checking of protective measures and of the electrical continuity of the protective circuits.
They complete the 7 manufacturer type tests and guarantee professionnalism and responsability of panelbuilder.
Schneider Electric supplies a full range of tools for assistance:
Quality inspection guide
switchboard assembly and installation guide
Prisma Plus System P and G assembly guides
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41. Test n°8 (8-3-1) : cabling, electrical operation
Check of mechanical actuating elements, interlocks, ... effectiveness
Check of proper laying of conductors and cables and proper mounting of device
Check of connections adequate contact, especially screwed and bolted connections.
Conditions
Results
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42. Test n°8 (8-3-1) : cabling, electrical operation
Conditions
Check of conformity with:
drawings, circuit and wiring diagrams
cabling (power and auxiliary connection)
cabling quality (cross-section, crimping...)
information and marking (cables and devices).
Visual inspection :
degree of protection, creepage distances and clearancess
technical data document (diagrams, characteristics...).
Mechanical and electrical functioning test :
check of cabling and most sensitive parts of the switchboard : (mechanical control facilities,interlocks...).
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43. Test n°8 (8-3-1) : cabling, electrical operation
Results
The design of the switchboard , a structure based on functional units, insures conformity to this test.
Schneider Electric gives the basic rules of assembly and installation in its documentation for assistance
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44. Test n°9 (8-3-4) : insulation resistance / (8-3-2) : dielectric test
No arc flash-over or insulator perforation must be observed between the live parts each other and between the live parts and the conductive structural parts.
Conditions
Results
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45. Test n°9 (8-3-4) : insulation resistance / (8-3-2) : dielectric test
Conditions
2 possibilities of test depending on the panelbuilder ’s means
either insulation measuring (8-3-4)
or dielectric test (8-3-2).
all electrical equipment shall be connected for the test, except those apparatus which are designed for a lower test voltage
the test voltage is applied :
- between each pole and interconnected exposed conductive parts - between each pole of main circuit and the other poles
- between each auxiliary control circuit and main circuit and exposed conductive parts
- between supply and withdrawable part of a switchgear .
Insulation test (8-3-4) :
insulation measurement using an insulation measuring device at a voltage of at least 500V.
Dielectric test (8-3-2) :
for a rated operational voltage of 240/400 V, the dielectric test voltage of 2500 V must be applied during 1 s.
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46. Test n°9 (8-3-4) : insulation resistance / (8-3-2) : dielectric test
Results
Verification of insulation resistance (8-3-4)
The test is passed if there is no perforation or flashover between the different tested parts
Dielectric test (8-3-2)
The test is passed if the insulation resistance between circuits and exposed conductive parts is at least 1000 Ohms/V..
The standardization of the distribution and conenctions is the best guarantee.
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47. Test n°10 (8-3-3) : protective measures
Checking of protective measures and of the electrical continuity of the protective circuits for metallic assemblies
Conditions
Results
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48. Test n°10 (8-3-3) : protective measures
Conditions
Visual inspection :
Checking of protective measures against direct and indirect contacts
Checking of the electrical continuity of the protective circuits for metallic assemblies (screwed and bolted connections shall be checked for adequate contact) possibly by random tests.
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49. Test n°10 (8-3-3) : protective measures
Results
Compliance of mechanical and electrical assembly instructions guarantees good electrical continuity of protection circuits.
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50. Panelbuilder and manufacturer, together to offer maximum safety and realibility
products tested in real configurations
detailed instructions for fautless construction.
Installer :
it has to its disposal informations, by means of tools of switchboard assembly and installation guide (catalogs, internet)
confidence in products and swichboards systems, the result of many years of experience
A shared success :
this complementarity must fall under the duration to consolidate our professionalism.
Customers advantages
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51. Panelbuilder and manufacturer, together to offer maximum safety and realibility
Customers advantages
Panelbuilders (and installators’ workshops) :
they complete a work of quality, simply
they minimize the risk related to their responsibility for realization of a switchboard of which they know and ensure the level of safety
they carry out very simply the conformity to the standard, therefore CE marking
they develop their professionalism by making known it
they are different from the other panelbuilders
they profit from the transfer of Schneider Electric ’s experiment and tools
Installators :
for them, a certified switchboard is the guarantee of the safety of installation and the good completion of work
it is also the certainty to fulfill the user ’s requirements
they minimize the risk related to their responsibility for installation
they show professionalism.
Users :
They have the certainty to have a switchboard ensuring
- the safety and whose the quality is proven
- maintenance and evolutivity easy thanks to the prefabrication and the standardization of the components
They are ensured of the equipment and components perennity.
They minimize the risks related to their responsibility for exploitation
Specifiers/consultants :
For them it is the certainty to prescribe a switchboard which ensures the level of safety required by the user.
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52. Prisma Plus and IEC 60439-1 standard : an international influence
IEC : the same standard for all the professionals of switchboards
Prisma Plus complying with the IEC standard: an international dimension.
IEC UL
IEC
IEC
IEC
IEC
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