MIL-STD-461G! Draft for Industry Review! Photo Goes Here Ken Javor! EMC Consultant! Ken Javor Content goes here! • 1! • 2! • 3! 30+ YEARS IN EMI/EMC Consultant to Government and Industry Industry representative to MIL-STD-461 and MIL-STD-464 Tri-Service Working Groups… ken.javor@emccompliance.com (256) 650-5261 PURPOSE OF STANDARD Controls EMI characteristics of equipment/ subsystems procured by DoD GO/NO-GO or Pass/Fail Requirements* Increases likelihood of compatibility in its EME Easier to build EMC into equipments/ subsystems that to Band-Aid it in during system integration * Officially - actually, not so much… APPLICABILITY Requirements depend on equipment/subsystem type and use 4 Standard Review /Comment Submission Your inputs can make a difference! The MIL-STD-461F change in how the rod antenna is used was prompted by an industry review comment that was submitted in response to the MIL-STD-461F draft for industry review (which didn’t address the issue at all). 5 Standard Review /Comment Submission MIL-STD-461G draft for industry review released on 01 April (!) and comments are due to DoD by 18 May. Comments submitted through a DoD website: https://assist.dla.mil/online/start/ It should allow you to set-up an account and then log into the specific site for 461 G comments. If you need a copy of the standard, it can be obtained from one of the industry reps, via email (3 MB attachment). 6 Electrical Bonding Requires measuring and recording bond values prior to cable connection and any further testing. No bond value requirements: bonding results must be in accordance with installation drawings/requirements. Requires LISNs bonded ≤ 2.5 milliohms. Sad But True (why do we need to put this in the standard?) 4.3.7.2 Excess personnel and equipment This section already said: “The test area shall be kept free of unnecessary personnel, equipment, cable racks, and desks. Only the equipment essential to the test being performed shall be in the test area or enclosure. Only personnel actively involved in the test shall be permitted in the enclosure.” Now the following is added: “Remove all equipment and ancillary gear not required, including antennas, from shielded enclosures not being actively used for a particular subset of radiated tests.” In other words, it’s a test chamber, not a broom closet… OTOH…. .l t F 9 2. a o ! i: il, x\ (r hg 9\ o rt. JN =8 vO \) O N MIL-STD-826A(USA r-} 30 June 1966 o8 q:: ir o=r ON 5$ .c-6-' v40 C^ i3'a .9 tsr 'o,9() rc bo9 ,€- 9€.| Oo^ E J jt (/l!iF * 6d5E= FCO, = ir-'* ;=; q6 e 9iebl l,l ,: f r5 0) 6 a :! tr. i I i6 t5 , )^&o ;d \{ Yo E F.g ;t,l rL 3:i ***Table II - Emission Sweeps*** 10 Table II - Emission Sweeps of 1 pps 10 us pulse Traditional EMI rcvr using 15 ms dwell time FFT EMI rcvr using 15 ms dwell time FFT EMI rcvr using 1 second dwell time From MIL-STD-461G Table II Appendix supporting information 11 General Set-Ups Expanded ground plane requirement (Figure 5) for equipments tested outside a shielded chamber. ***Detailed requirements (4.3.8.6.1) on cable routing for large floor-standing equipment. *** ***Further in the standard, under RE102 and RS103, more requirements on antenna placement positions for equipments with height as well as width. *** 12 ***4.3.11 Change in Routine Calibration Requirements*** 4.3.11 Calibration of measuring equipment. Primary measurement devices and accessories required for measurement in accordance with this standard shall be calibrated in accordance with ANSI/ISO/IEC 17025 or ISO 10012 or under an approved calibration program traceable to the National Institute for Standards and Technology. After the initial calibration, for passive devices such as measurement antennas, current probes, and LISNs, no further calibration is required. The measurement system integrity check in the procedures is sufficient to determine acceptability of passive devices. Suggested change acknowledges that passive device calibration is quite different than calibrating an EMI receiver and cycle times and procedures are significantly different. Balloting on SAE AIR 6236 for such passive device calibration is underway to support the change. 13 4.3.11 Test Equipment Calibration Change 14 TABLE IV. Emission and susceptibility requirements CS106 deleted. New! New! 15 Table V. Requirements Matrix 16 5.5 CE102 When performing the measurement system integrity check, there is an extra step that confirms LISN impedance is in tolerance below 2 MHz. This is in lieu of calibrating LISNs on a periodic cycle. 17 5.6 CE106 Transmit requirement becomes very complex if application is high power Navy ship topside installation. The 5% frequency exclusion becomes transmit power dependent: The Navy topside limit becomes independent of transmit power: “Transmitters and amplifiers (transmit mode): Harmonics, except the second and third, and all other spurious emissions shall be at least 80 dB down from the level at the fundamental. The second and third harmonics shall be suppressed to a level of -20 dBm or 80 dB below the fundamental, whichever requires less suppression. For Navy shipboard applications, the second and third harmonics will be suppressed to a level of -20 dBm and all other harmonics and spurious emissions shall be suppressed to -40 dBm, except if the duty cycle of the emissions are less than 0.2%, then the limit may be relaxed to 0 dBm.” 18 5.7 CS101 Change 5.7 CS101 Solution Performance Comparison 800 Hz CS101 Ripple Performance Comparison 100 Hz CS101 Ripple The Past Into the Future? – No. Testing at frequencies below the power frequency. 22 5.11 CS106, Conducted Susceptibility, transients, power leads DELETED. No justification exists. Tests indicated that CS115 couples the same amount of crosstalk into a wire adjacent to the power wire with transient as when using the transient itself. From a review of MIL-STD-461F when it was new: The purpose of this requirement is however entirely different than when CS06 was developed and required in MIL-STD-826 and MIL-STD-461 A/B/C. CS106 has little to do with electrical power quality except modeling coupling from power bus transients to signal lines within an equipment enclosure. It is now a special purpose cross-talk test limited to Navy procurements, particularly submarines, which requested and justified it, as follows (from the rationale appendix): "The Navy submarine community has found the obsolete CS06 of MIL-STD-461 (through revision C) requirement to be an effective method to minimize risk of transient related equipment and subsystem susceptibility. This type of transient susceptibility test has been successful in early identification of transient related EMI problems in naval equipment and subsystems. The Navy has found good correlation between transient related shipboard EMI problems, including longevity, degraded performance and premature failures, and CS106 susceptibilities." Most of the problems uncovered by the heritage CS06 requirement were not with the power input circuitry, but rather other circuits which were affected by cross-talk between power and signal wiring within the test sample. 23 ***5.12 CS114, Conducted Susceptibility, Bulk Cable Injection*** S E-field spatial variation E-field spatial variation line is electrically short E length = λ/4 Field-To-Wire Coupling (Vi/E), Normalized coupling efficiency Vi = 2h sin (πl/λ) Ei length = λ/2 (max coupling) line length = λ ( 1st null) f = (2n+1)c / 2L, n an integer 0 -10 -20 f = n c / L, n an integer -30 -40 L = λ/200 L = λ/20 L = λ/2 electrical length 24 ***5.12 CS114 – Major Impact on Shielded Cables! *** Level on current as present or on precalibrated forward power? IN Compliance magazine, October 2014 issue 5.12 CS114 When performing forward power calibration, the current probe used to monitor injected current must also be verified. ***5.15 CS117 – Lightning Indirect Effects*** Purpose: Lightning is not a new requirement for DoD platforms; but it is being included in MIL-STD-461 so as to eliminate the need to separately call out a non-DoD standard. Borrowed from RTCA/DO-160G Section 22. At present time, no pin injection. Levels don’t exceed RTCA/DO-260 section 22 Level 4. Includes multiple stroke and multiple burst. If a test facility has a section 22 lightning capability to Level 4, they can perform the MIL-STD-461 version. ***5.16 CS118 – ESD*** Personnel borne electrostatic discharge Applicable to electrical, electronic, and electromechanical subsystems and equipment which does not interface with or control ordnance items Leverage from Industry ESD standards RTCA/DO-160 section 25 IEC 61000-4-2 “Gun” definition per RTCA/DO-160 section 25. Target per IEC 61000-4-2 Levels from 2 to 15 kV. Levels below 15 kV are default contact discharge; 15 kV is air discharge. Risetime 0.6 ≤ tr ≤ 1 ns 5.18 RE102 Issues under discussion for -461G (no guarantee of concrete action due to time constraints: Rod antenna optimization Proper set-up – was in draft2, not in released draft Proper measurement system integrity check using correct capacitor value – YES. Proper capacitance based on counterpoise size: TBD… Proper illumination of test samples with height larger than antenna spot-size. 5.18 RE102 Three things you don’t want to see: Sausage-making Law-making Standard-making 5.18 RE102 -461F fixed a resonance issue with the rod antenna measurement. -461G was trying to make the -461F connection not dependent on a ground plane connection. The idea is to use isolation, either transformer, or optical. Optical has been done, and it works, but $ $$. -461F -461G desiderata No floor connection required XFMR or optical isolation 5.18 RE102 Transformer trials 1:1 isolation 50 Ohm XFMRs with little or no loss 10 kHz to 30 MHz 5.18 RE102 Rod antenna measuring electric field from wire over ground plane. 5.18 RE102 Rod antenna measuring electric field from wire over ground plane, using MIL-STD-461E connection. 5.18 RE102 Rod antenna measuring electric field from wire over ground plane, using MIL-STD-461F connection. 5.18 RE102 Rod antenna measuring electric field from wire over ground plane, using isolation transformer connection. 5.18 RE102 Rod antenna measuring electric field from wire over ground plane, using a different isolation transformer connection. 5.18 RE102 -461E connection Looks pretty good here, but WPAFB gets different results. -461F connection Not resolved. Isolation XFMR Not ready for prime time L Second isolation XFMR 5.19 RE103, Radiated Emissions, Antenna Spurious and Harmonic Outputs, The same Navy topside high power transmitter changes apply to RE103 (frequency exclusion and fixed transmit limit) as for CE106 39 5.21 RS103, Radiated Susceptibility, Electric Field 5.20.1 RS103 applicability (-461F). This requirement is applicable to equipment and subsystem enclosures and all interconnecting cables. The requirement is applicable as follows: a. 2 MHz to 30 MHz Army ships; Army aircraft, including flight line; Navy (except aircraft); and optional* for all others b. 30 MHz to 100 MHz all (except Navy aircraft) c. 100 MHz to 1 GHz all d. 1 GHz to 18 GHz all e. 18 GHz to 40 GHz optional* for all *Required only if specified in the procurement specification There is no requirement at the tuned frequency of antenna-connected receivers except for surface ships and submarines. 5.21.1 RS103 applicability (-461G). Much simpler, due to NAVAIR changes. This requirement is applicable for equipment and subsystem enclosures and all interconnecting cables. The requirement is applicable as follows: a. 2 MHz to 30 MHz Army ships; Army aircraft, including flight line; Navy; and optional* for all others b. 30 MHz to 18 GHz All c. 18 GHz to 40 GHz Optional* for all *Required only if specified in the procurement specification For Air Force only: There is no requirement at the tuned frequency of antenna-connected receivers. 40 5.21 RS103, Radiated Susceptibility, Electric Field MIL-STD-461F 5.20.3.4.c(2) RS103 Receive Antenna (calibration) procedure (> 1 GHz) is eliminated in MIL-STD-461G 41 Thanks for attending! Don’t miss our Test Bootcamp! November 12, 2015 www.emclive2015.com!
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