complete animated and info graphic description of EMI and EMP and EMC along with definition, causes, effects, products for EMI / EMP shielding and preventive measures
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● Part – I What is EMI, EMP and EMC?
● Part – II Causes / sources of EMI and EMP
● Part – III Effects of EMI and EMP
● Part – IV Mil Stds for EMI / EMP Protection of C4I Facilities
● Part – V Preventive Measures
5. Electromagnetic Pulse - Powerful pulse of short duration
and high intensity electromagnetic radiation such as
lightening or nuclear explosion.
Nuclear Blast
Definition
6. • Ability of IT Eqpt to operate in proximity of
electromagnetic envmt (EMI&EMP), without causing
or suffering unacceptable degradation in output or
performance
Definition
7. • 100% electronic shielding and containment.
• No EMI signal can enter inside DC
Definition
10. EMI EMP
EMI is a low intensity
interference
EMP is a high intensity interference
Interfere the electronic /
electrical devices but does not
cause damage
It damages electrical / electronic eqpt
Definition
24. EMI / RFI - 20 dB (10 times higher than normal lvl)
EMP - 20-90 dB (10-30000 times higher)
NEMP - 20-90 dB (10-30000 times higher)
NNEMP - 30-60 dB (30-1000 times higher)
Definition Causes Effects
25. EMI - 20 dB
RFI - 20 dB
EMP - 20-90 dB
NEMP - 20-40 dB or 60-90 dB
NNEMP - 30-60 dB
HEMP - 20-40 dB
29. Standard for EMP hardening of fixed ground-based
and transportable C4I facilities and prescribed fol:-
Min performance Req
Min test req
Design and test criteria
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Definition Causes Effects Stds
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Faradays Cage
Shielding Cover
Al / Cu / Steel
1
Use Shielded
Power Cable
2
Proper Earthing3
Definition Causes Effects Stds
Preventive
Measures
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Option I
Shielding at Device lvl
Not Recom
Option II
Shielding
Enclosures
Recom
Option III
Shielding of Room
Not Recom
Definition Causes Effects Stds
Preventive
Measures
33. Option 1 : Shielding at component or device Lvl
(individual SW, FW or Chassis etc)
Pros :
No need to design Big infra for shielding
No structural changes req
Cons :
Expensive
Req lot of time for implementation
Difficult to implement
Difficult to op and maint
Concl : Not Recom
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Definition Causes Effects Stds
Preventive
Measures
34. Option 2 : Shielding Enclosures – Faraday’s cage (at
Row Lvl )
Pros :
No need to design Big infra for shielding
No structural changes req
Customized solns are aval
Easy to implement
Not Expensive
Cons :
Racks are req to disassemble
Req 1 week time to implement
Cooling may be disturb but
honeycomb vents can compensate
Concl : Recom
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Definition Causes Effects Stds
Preventive
Measures
35. Option 3 : Shielding of Room (6 sided shielding
of room )
Cons :
Need to design Big infra for shielding
Structural changes req
Ceiling changes are req
Floor changes are req
Difficult to implement
Expensive
Racks are req to disassemble
Req lot of time to implement
Concl : Not Recom
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Definition Causes Effects Stds
Preventive
Measures
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Lvl 2 : Meet or exceed lvl 1 req
• Surge protection device on power cord, data and comm cables
• Dedicated EMP protected power supply
• Double conversion UPS
• Use fiber optics
• Shielded cable
• Shielded Rack, Room or facility
• EMP filters
•
Lvl 1 :
• Turn off eqpt – unplug power and data / comm lines
• Wrap spare electronic eqpt with aluminum foil
• Dedicated EMP protected backup power supply for 1 week
Definition Causes Effects Stds
Preventive
Measures
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Lvl 4 : Meet or exceed lvl 3 req
• Use Military EMP std MIL-STD-188-125-1
• 80+ dB shielding protection
• Double door EMP protected safe entry
• 30+ days of EMP protected power backup
Lvl 3: Meet or exceed lvl 2 req
• Use civ EMP protection std (IEC SC77C)
• 30-80 dB shielding protection through 10GHz
• SPD for eqpt outside shielded area
• Single door EMP safe entry
• 30 days EMP protected power backup
Definition Causes Effects Stds
Preventive
Measures
40. Conductive Paint thickness – 0.025 mm to 0.050 mm
Pros :
Easy to use – spray
Cost effective
Cons :
Mostly all conductive paint are designed for plastic casing of
devices.
Paint can’t block medium and low freq signal.
Such paint can’t be used for masonry work.
Paints deteriorate with time – making shielding highly
ineffective.
It may not be used for more than 3’ x 3’ x 3’ dimension.
Attenuation lvl is less (<30 dB)
Concl : Not Recom1/14/2018 40
41. EMI Shielding Gaskets – use to avoid gaps and
completely contain the shielding
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Definition Causes Effects Stds
Preventive
Measures
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Preventive measure
Faradays cage on double row (HAC) :-
• Material – Copper (preferred steel)
• Cage - 3-6 mm thickness
• 80+ dB shielding protection
• Double door EMP protected entry
Surge protection device at svc entrance – Type 1
Surge protection device at distribution / sub panels – Type 2
Surge protection device at point of use (ferrites) – Type 3
Generator with 30+ days backup must be EMP protected
Double conversion UPS
Shielded cable
Proper grounding
Lightening arrester
Proper cable layout (metal cable tray and tight bundles etc)
Power Line Filters
Data / Signal Line Filters