Miracel EMC Rack Details - dafnia.com Rack Solution...Miracel EMC Rack Details. ... No specification without EMC !!! Specification Prototype Production ... filtering, grounding. Michael

Miracel EMC Rack

Details

Michael Klatt

Application Engineer

Knürr Electronics GmbH, Arnstorf

2013, January 30th

EMI interfaces

ElectronicPower supply Signal lines

Coupling

Michael Klatt



2013, January 30th

Coupling mechanism

Magnetic fields

– inductive

Electric fields

– capacitive

Electromagnetic fields

Interference currents into cabling

– galvanic

Michael Klatt



2013, January 30th

No specification without EMC !!!

Specification Prototype Production Customer

Relative costs

1

10

100

1000

Technical

possibilities

Michael Klatt



2013, January 30th

Make sure that your system is EMC

With other systems and/or with the environment

Definition of the requirements:

– Interference field strength (maximum)

– Immunity (minimum)

EMC interferences

Testing procedures

important steps:

– Shielding, cabling, filtering, grounding

Michael Klatt



2013, January 30th

What do you have to think about ?

Rack/case:

– right and sufficient shielding

Cabling / Filtering / Grounding

– no influences into/out of the system

Ventilation

– cooling with shielding

Cable inlet

– easy to handle

– cost-effective

ESD

– protect your system

Michael Klatt



2013, January 30th

Steps to EMC

Narrow screwing

EMC spring

Material contact

Ventilation:

small holes

honeycomb filter

PSU

Mains filter

Signals

Screen contact

both sides

Highly

conductive,

sufficient thick

material

GND

separation

as required

Waveguide:

good mass contact

Michael Klatt



2013, January 30th

Shielding

protects

against

electromagnetic interferences

Michael Klatt



2013, January 30th

Shielding of a case

Material High conductivity

Surface Low impedance

Connections Low impedance

Openings No or small

Openings sealed

Ventilation many small holes instead of somebig holeshoneycomb filters

Michael Klatt



2013, January 30th

Points of discontinuity

“leaky“ connection

Ventilation:

Size + quantity of holes

Corrosion

Badly conductive material

Material thickness

Michael Klatt



2013, January 30th

Test setup ( VG 95373 )

Test 1: without rack (dBµV)

Test 2: with rack (dBµV)

Shielding attenuation = Test 1 - Test 2 (dB)

Highly shielded room with absorber

Rack

Signal

generator

Receiver

Michael Klatt



2013, January 30th

Test results (example)

Test1 without rack maximum field strength

100 200 500 1000 MHz

50

100 dB

Michael Klatt



2013, January 30th


Test 2 with rack field strength in the rack

100 200 500 1000 MHz

50

100 dB

Michael Klatt



2013, January 30th


Shielding attenuation: Test1 - Test 2

100 200 500 1000 MHz

50

100 dB

Michael Klatt



2013, January 30th

Increasing of shielding attenuation

ferromagnetic

material

Conductivity

Permeability

Thickness of material

Less quantity of openings

Better connections

Smaller

openings

Sh

ield

ing

atte

nu

atio

n

Frequency

Michael Klatt



2013, January 30th

Cabling: Requirements

Protect against:

“In-coupling” of interferences

“Out-coupling” of interferences

Coupling within the cabling

Michael Klatt



2013, January 30th

Coupling into cabling

by:

Magnetic fields

"inductive"

Electrical fields

“capacitive"

Electro magnetic fields

„resonant range“

Disturbing current on cabling

“galvanic"

Michael Klatt



2013, January 30th

Cable inlet

Use shielded cables

– HF currents go from cable shield to the surface of the case, not into the case

Use modular cable inlet

– easy to handle

– standard

– cost effective

For highest shielding use cable inlet for each cable, if necessary with integrated filter

HF currents

Michael Klatt



2013, January 30th

Miracel Design - Basic Frame

Universal Extrusion

IP

EMC

Assembly

Corner part

Michael Klatt



2013, January 30th

EMC-Concept - Miracel Double walled

Usage of stainless steel springs, Knürr patented, cost effective

Easy removable and reinstallation of used EMC springs

Secure contact to aluminium extrusions

Labyrinth effect due to the double walled concept increases the screening attenuation

Side panels removable.

Visible cover parts acc. Miracel standard parts. EMC screening performed with internal second EMC layer

EMC capabilities add-on

Usable for a large frequency range

Double walled concept is unique at the market – no competition

Protection of the EMC level done with outside IP sealing

Michael Klatt



2013, January 30th

Miracel EMC-Concept

Excellent screening:

Efficient screening concept for different requirements and for a different frequency range

ideal material combination (to prevent electro chemical corrosion)

Adapted sealing / springs (Stainless steel spring)

EMC design

flexible Accessories

Michael Klatt



2013, January 30th

Miracel EMC

Excellent shielding by:

effective shielding concept

ideal combination of materials

continuous high-grade stainless steel EMC springs

Michael Klatt



2013, January 30th

Miracel EMC - basic construction

EMC spring

IP seal

EMC tough panel

EMC tough panel

IP seal

IP side panel

IP front panel

vertical extrusion

“Sandwich” construction of front door and side panel

Michael Klatt



2013, January 30th

Miracel EMC double walled – Exploded Sample

Custom specific solution

Michael Klatt



2013, January 30th

Miracel EMC double walled – Test results

Michael Klatt



2013, January 30th

Miracel EMC - accessories

Michael Klatt



2013, January 30th

Modular cable inlet

Simple handling:

– Expose braided shield

– Push through cable with connector

– No cutting of cables

– Clamp cable with seal

Cost effective

Integrated in:

– Rack/Minirack

– Card frame

– Front/Rear/Bottom/Top

cable shield

EMC

meshcable

connector

Michael Klatt



2013, January 30th

Thermal management

Ventilation

– perforated top+bottom cover/doors

– integrated fan trays

– external fans

Heat exchanger

Air conditioning

many small holes

don‘t disturb the shielding concept

use mains filter

Michael Klatt



2013, January 30th

TestsPassed tests

IP-Test (DIN 40 050)

Vibration / shock test (MIL-STD 810 E)

UL 1244

NEMA 12 Standard

EMC (MIL-STD 285 / VG 95373)

Seismic test (Bellcore)

Earth continuity (VDE 0100)

Michael Klatt



2013, January 30th

EMC with Knürr

Knürr simplifies the certification of your product

EMC products for each application

All products designed and produced according to the standards

Products are approved (TÜV, CE, VDE, UL...)

Production control by TÜV, VDE, UL

Certification ISO 9001

Michael Klatt



2013, January 30th

Emerson Network Power Enabling Business-Critical Continuity™

Documents

Miracel EMC Rack Details - dafnia.com Rack Solution...Miracel EMC Rack Details. ... No specification without EMC !!! Specification Prototype Production ... filtering, grounding. Michael