Sept 2007 Labday Safety Presentation

7/31/2019 Sept 2007 Labday Safety Presentation

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Outline

Background

InsulationComponent Selection

Labeling

Documentation

Wiring

Resistance to Fire


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Product Safety Requirements

US/Canada:NRTL Listing (cULus, cTUVus, cCSAus)

Legal requirement, customer requirement, or to limit liability

Europe:CE Mark

Legal requirement

Others:CB Report

To facilitate International Approvals.


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Product Safety Hazards Electric Shock Hazards: Accessible parts over 30Vrms,

42.4Pk, or 60VDC.

Energy Hazards: Energy level over 240VA or 8A

Fire Hazards: Materials, Enclosure, Abnormal conditions

Mechanical Hazards: Moving parts, Sharp edges,Tipping, Handles

Radiation Hazards: Lasers, UV, Sonic

Thermal Hazards: External temps, component temps


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Product SafetyDesign Guidelines


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Design Requirements

Protection against electric shock andenergy hazards:

The OPERATORcan not touch bare or inadequatelyinsulated parts at hazardous voltage or energy levels.

Hazardous Voltage Level is typically >30Vrms,42.4Vpeak, or 60VDC.

Hazardous energy is typically >240VA or 8A

Protection may be provided via insulation, guarding orinterlocking.


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What is Insulation? Physical barrier between two parts

(tape, plastic shield, wire insulation,

enclosure, etc)

Separation between two parts through

air or along a surface (creepage orclearance distance)


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Insulation Types

Functional / Operational Insulation (DC

input to ground)

Basic Insulation (Primary to Ground,TNV to Ground, TNV to SELV)

Reinforced Insulation (Primary toSecondary)


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Reinforced Insulation Example


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Spacings (Creepage / Clearance)

Based on the required insulation for your circuit.

Based on the maximum working voltage for yourcircuit.

Based on the environment the product will be used in

(Pollution Degree)

Based on the PCB material: Material Group -

Comparitive Tracking Index (CTI)


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Creepage / Clearance


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Creepage / Clearance

Creepage Creepage = distance between two points along the

surface

Creepage is measured on 1:1 artwork or on a blank board

Locations of circuits determined by reviewing schematics

Clearance Clearance = distance between two points through the air

Clearance is measured on a populated sample


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Component Selection

Safety Critical Components must have theappropriate approvals or additional evaluationwill be required.

Safety Critical Components: Devices in the AC path (inlets, fuses, switches, power

supplies, transformers, etc.) Motors, fans Power conversion components (AC-DC or DC-DC

Converters)

Any isolation component (Transformer, BridgingCapacitors, MOVs,) Wiring Batteries Others depending on their application.


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Component Selection For NRTL approvals, all components must be UL approved.

For CE Mark approvals, all components must have aEuropean approval such as CE, TUV, VDE, etc. (exception:fuses and wiring can be UL approved)

For GS or CB Scheme approvals, all components musthave a TUV, VDE, or other official European approval. CE

Mark is not acceptable for these approvals.

Approval certificates required (TUV or VDE Cert, CEDeclaration of Conformity, UL File number, etc.)


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Labeling and Marking

Rated voltage, current or power, frequency

Manufacturers name or registered

trademark. Model or type number.

Fuse replacement info (if applicable).

IEC symbols wherever possible. Warnings and Cautions appropriate for the

particular equipment.


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User Instructions

Installation Instructions - information regardingmounting, connection to the supply, ventilation, inputratings, etc.

All information regarding use, cleaning, maintenance(if necessary).

All safety warnings and cautions.

Rack Mount instructions.

Safety-related information to be in appropriate

language of the country you are exporting to. Some standards have entire sections of specific info

that must be in manual.


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Wiring and connection to the supply

Protective Earth - PE conductor must be green/yellow or bare insulation

conductor

PE connections must be double secured so that both

the wire and insulation are crimped

IEC PE symbol shall be marked adjacent to PE stud

PE conductor shall connect to chassis directly from

input (inlet, terminal block, etc).

PE conductor must be secured with washer and

locknut.

Additional PE conductors can be secured to PE stud

with a second washer and locknut.


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EMI FILTER

TO OTHER

GROUNDS

GROUND: GREEN/YELLOW WIRE

SAME GAUGE AS OR BIGGER THAN SUPPLY

CHASSIS

CONNECTION

MECHANICALLY SECURED

PE Stud Example


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Wiring and connection to the supply Primary Wiring -

All AC wires shall be double secured. Double securement can

be met by:Double crimp connector or

Single crimp connector and cable tie or

Single crimp connector and shrink sleeving.

AC wiring shall be rated for the maximum working voltage andcurrent.

AC wiring shall be isolated from low voltage wiring or lowvoltage parts, this can be accomplished by:

Shrink sleeving the AC conductors or

By routing the AC conductors away from low voltage wires

and securing with cable ties or

By using UL1015 Reinforced Insulation wire.


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Resistance to fire and control

of fire spreading Enclosures, components, and other parts shall be

constructed such that propagation of fire is limited.Flammability of enclosure, internal, and external parts shallbe adequate for the use of that part.

Flammability ratings

5VA Most fire resistant 5VB

V0

V1

V2

HB40 HB75 - Least fire resistant

Foamed materials:

HF-1

HF-2

HBF


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Resistance to fire and control of

spread of fire

60950-1

Fire enclosure openings shall be: Top and side openings shall be:

less than 5mm in any dimension or

less than 1mm in width regardless of length or

meet the 5 projection rule.

There shall be no bottom openings (some exceptions

allowed but difficult to meet)


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Methods for Meeting FireRequirements in 61010-1 Requirement: There shall be no spread of

fire outside the equipment in Normal or Single

Fault Conditions.

Methods of Compliance:

A: Testing in single fault conditions

B: Reducing sources of ignition within theequipment

C: Containing fire within the equipmentshould it occur


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Requirements for fire enclosure

- Components in primary circuit

- Components in secondary circuits that are not supplied by LPS

- Components in secondary circuits supplied by LPS

but not on V-1 material

- Components with unenclosed arcing parts

- Insulated wiring


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Parts not requiring Fire Enclosure

- Motors

- Transformers

- Wiring and cabling insulated with PVC, TFE, PTFE,

FEP, neoprene or polymide

- Connectors in secondary circuits powered by less

than 15VA or LPS

- Components in secondary circuits supplied by LPS

and on V-1 material

- Components in secondary circuits supply by max

15VA and on HB785 if 3mm.


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Plastic materials used for fireenclosure Movable equipment


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Plastic materials used inside a fireenclosure Inside a fire enclosure:

V-2 or HF-2 or pass A.2

Exceptions:

Electronic components (ICs, optos, etc.) mounted onV-1.

Wiring and connectors insulated with PVC, TFE,PTFE, FEP, neoprene, or polymide.

Clamps, cable ties.

Wire marked VW-1 or FT-1 or better.

Others.


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Plastic materials used outside afire enclosure Material outside fire enclosure:

HB75 if 3mm or HBF or Glow Wire test at550C

Connectors:

V-2 or pass A.2 or mounted on V-1 and be small or be insecondary circuit with max 15VA

Exceptions: Electronic components (ICs, optos, etc.) mounted on V-1.

Wiring and connectors insulated with PVC, TFE, PTFE, FEP,neoprene, or polymide.

Clamps, cable ties.

Others.


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Washington Laboratories, Ltd.

Help you select the proper Directives and

Standards to apply to your product.

Evaluate and test your product to the

appropriate Safety Standard and offersolutions for non-compliances.

Provide product design assistance.

Obtain cTUVus, cCSAus, cULus, GS Mark,and other approvals.

WLL is a Partner Test Lab for TUV Rheinland

for 60950-1, 61010-1, and 60065


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Washington Laboratories, Ltd.

Give us a call or send us info about your product -were here to help!

Berri Remenick

Product Safety Manager

Phone: 301-473-1255

Fax: 301-473-1257

E-mail: [email protected]

Documents

Sept 2007 Labday Safety Presentation