1、DOD-STD-2145 bL 97997LL 0012614 1 9 1 F IMETRIC 1 DOD-STD-2145(SH) 1 June 1983 MILITARY STAhTDARD DISCONNECT SWITCH BOXES, CONTACTOR PANELS AND SWITCHBOARDS, LOW MAGNETIC FIELD DESIGN OF (METRIC) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I . :-
2、 DOD-STD-2145(SH) 1 June 1983 DEPARTMENT OF THE NAVY NAVAZ, SEA SYSTEMS COMMAND Washington, DC 20362 Disconnect Switch Boxes, Contactor Panels and Switchboards, Low Magnetic Field Design of (Metric). DOD-STD-2145(SH) 1; This Military Standard is approved for use by the Naval Sea Systems Command, Dep
3、artment of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Sea Systems Comman
4、d, SEA 5523, Department of the Navy, Washington, DC 20362 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. ii : -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
5、-,-,-I . ?. . t Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2195 61 m 7777711 0012b21 7 W DOD-STD-2145(SH) 1 June 1983 3.1.13 Three-terminal device. A three-terminal device is equipment in wiiich three terminals, one positive and two nega
6、tive, or two positive and one negative, project from the device for connection to a cable run. The device (that is, disconnect switch boxes and contactor panels) may have inultiple sets of three terminals for incoming and outgoing cable runs. 3.1.14 Two-terminal device. A two-kerminal device is equi
7、pment. in which two terminals, one positive and one negative, project from the device to a cable run. 4. G3NEA.L REQUIREMENTS 4.1 Conductor and device arrangement. Conductors for and the devices in the power circuits for disconnect switch boxes, contactor panels, switchboards, power panelS.and motor
8、 controllers shall be physically arranged and intercon- nected in a manner that will result in circuits which produce a minimum stray magnetic field. 4.2 Simplicity of conductor and device arrangement. Arrangement of con- ductors and devices for the power circuits shall be uncomplicated and straight
9、- forward and, at the same time, produce a minimum stray niagnetic field. 4.3 magnetic moment separation. circuits shall be kept as small as possible to minimize the magnetic moments of the current loops. The distance between these current loops shall also be miniinized. required by khe electrical c
10、reepage and clearance distances of the applicable specification for the disconnect switch boxes, contactor panels, switchboards, power panels and motor controllers. Arrangement of power circuit for minimum magnetic moment and minimum The siz,e of current loops, created by the power Conductor and dev
11、ice separation shall be kept to the minimum 4.4 Arrangement of power circuit for minimum net magnetic moment. Current loops created by the power circuits shall be arranged such that the resultant or net magnetic moment will be minimized. 4.4.1 Utilization of parallel compensation in the arrangement
12、of power circuits. Parallel compensation shall be utilized in the arrangement of power circuits in order to assist in achieving a minimum net magnetic moment. Elec- trical resistance of parallel conductors shall be equalized, as required by a particular circuit arrangement, so that maximum parallel
13、compensation is achieved. 4.5 External cable connections to disconnect switch boxes and contactor panels. External cable connections shall be made in accordance with DOD-STD-2133. 4.6 Material. Material used in the construction of disconnect switch- boxes, contactor panels, switchboards, power panel
14、s and motor controllers shall conform to the material requirements of DOD-STD-2143. 3 f“ . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2145 b1 9777731 0032b22 O a DOD-STD-2145(SH) 1 June 1983 5. DETAILED REQUIREMENTS 5.1 Basic conductor a
15、rrangement. The basic arrangement of conductors in disconnect switch boxes, contactor panels, switchboards, power panels and motor controllers shall be a central conductor carrying two units of current in one direction sandwiched between two symme,trically placed conductors each carrying one unit of
16、 current in the opposite direction, as illustratedon figure 2. basic conductor arrangement is compatible with the three-terminal arrangements for magnetic minesweep quad cable runs in accordance with DODiSTD-2133. Consequently, disconnect switch boxes and contactor panels with this basic conductor a
17、rrangement are three-terminal devices. The 52 Conductor bends. Conductor bends can be one of two types: (a) the conductors lie in different planes on each side of the bend or (b) the conductors lie in the same plane on each side of the bend. 5.2.1 Conductors lying in different planes on each side of
18、 the bend. Bending of conductors shall.be accomplished as illustrated on figure 3 when the conductors lie in different planes on each side of the bend. This arrangement will result in zero net magnetic moment of current when the currents in the two outside conductors are equal. 5.2.2 Conductors lyin
19、g in the same plane on each side of the bend. Bending of conductors shall be accomplished as illustrated on figure 4 when the conduc- tors lie in the same plane on each side of the bend. result in zero net magnetic moment of current when the currents in the two outside conductors are equal. This arr
20、angement is difficult to accomplish in practice. Consequently, the preferred power circuit arrangements for dis- connect switch boxes and contactor panels (see 5.4.2) utilizes conductor bends lying in different planes on each side of the bend. This arrangement will -5.3 Devices in power circuits. De
21、vices in power circuits are usually series connected devices, such as ammeter shunts and overload relays. These devices are two-terminal devices and can be connected directly into the circuit or first converted to a three-terminal device and then connected into the circuit. 5.3.1 Direct connection o
22、f devices into the circuit. Direct connection of devices into the circuit shall be accomplished by inserting the device into the circuit of the central conductor on figure 2. The two outer conductors shall be spread symetrically around each side of the device. 5.3.2 Conversion to a three-terminal de
23、vice. If a two-terminal device is placed in a three-terminal box, it shall be connected into the circuit as Illustrated on figure 5. 5.4 Power circuit arrangements. Power circuit arrangements shall be of the folded or crisscross type. not be used. The straight-through type of arrangement shall 5.4.1
24、 Straight-through arrangement. The straight-through arrangement, as illustrated on figure 6 for a disconnect switch box, shall not be used since the creation of a low-stray magnetic field with this design is very dependent upon equal current division between the two outer conductors. 4 .- Provided b
25、y IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2145 61 99799LL 0032623 2 DOD-STD-2145(SH) 1 June 1983 5.4.2 Folded arrangement. The folded arrangement, as illustrated on fig- ure 7 for disconnect switch boxes and figure 8 for contactor panels, shall b
26、e the preferred arrangement. where special circumstances make it indispeneable or highly advantageous to have a disconnect switch box or contactor panel with incoming and putgoing terminals at opposite ends of the box or panel. the incoming and outgoing terminals to be at the same end of the box or
27、panel. Actual separation of conductors shall be the minimum required to meet the appli- cable electrical creepage and clearance distances specified for the disconnect This zrrangement shall be ueed in all cases except The folded arrangement inherently requires switch box. I - a , Preparing activity:
28、 Navy - SH (Project 61100N239) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2L45 b1 77777LL 0012624 4 W l. l i DOD-STD-2145( SH) 1 June 1983 . I I 1 unit of current Area A I I 2 units of current I I - .L c Area B 1 unit of current Area A =
29、 Area B . SH 12228 FIGURE 1. Parallel compensation. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2145 b1 7999931 00L2b25 b W -. 8:. . -3 - -. . . “ ._. . -.Q :. * .I DOD-STD-2145(SH) 1 June 1983 1 unit of current 5 X I 2 units of current D
30、istance X equals Distance Y Y 1 unit of current 1 -: *-tj NOTE: In all figures, quantity of arrows indicates relative magnitude of current6 The direction of the arrows indicates direction of current. “c . ._ +sr- : t 4 *E SH 12229 switch boxei 7 - Provided by IHSNot for ResaleNo reproduction or netw
31、orking permitted without license from IHS-,-,-DOD-STD-2145(SH) 1 June 1983 - ._ - .-. - , 1 Angle of the bend (angle A) is the same for all three conductors. . . A. Conductor bend in two planes. I n If the currents in the two outer conductors are equal and if Area A = Area B and Area C = Area D, the
32、n zero net magnetic moment of cur- rent will result. B. Resulting current loops. SH 12230 FIGURE 3. Bend for conductors lying in different planes on each side of the bend. 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i r. . : ,_ -. . . . . . . .
33、 s .% sc , .c. .- z DOD-STD-2145 bL W 7777711 0012b27 T DOD-CTD-2 145 ( SH) 1 June 1983 If the currents in the two outer conductors are equal and if Area A = Area B, then there is zero net magnetic moment of current. SH 12231 FIGURE 4. Bend for conductors lying in the same plane on each side of the
34、bend. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i - . - I . . ._._. -_*_ - 1 . . - . .- j - . -1 ” ._“i .: .I . . _. DOD-STD-ZIqS 61 W 77777LL 0012628 I U DOD-STD-2145(SH) 1 June 1983 Three-terminal device box / , Through conductor, (e.g., bus
35、bar) _ Two terminal device A. Circuit for a two-terminal device in a three-terminal box. Current loop E = -(current loop F) Current loop C = Current loop A = -(current loop 8) -(current loop D) Current loop G = H) Frrent loop i = -(_current loop J) -AE t L r CABLE RUN CONNECTION BOX CONNECTION CABLE
36、 RUN B. Resulting current loops for circult in A. SH 12232 FIGURE 5: Conversion of a two-terminal device to a three-terminal device and resulting current loops. 10 - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 DOD-STD-2145(SH) ,1 June 1983 T T
37、A. Circuit for disconnect switch box with a straight- throuph conductor .arrangement. ro net magnetic moment is not achieved unless the current in the two outer loops are exactly equal to each other. b B. Resulting current loops for circuit in A. SH 12233 FIGURE 6. Straight-through arrangement (not
38、to be used) for a disconnect switch box. 11 Y A= Area B Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-ZLLI5 bL 77777LL 00L2b30 T m DOD-STD-2 14i (SH) 1 Jne 1983 Area A = Area B = Aiiea C = Area D Area E = Area F A. Circuit for disconnect sw
39、itch box with a folded arrangement. Net magnetic moment for loops A, B, C and D is equal to zero regardless of equal current division between the two outer conductors. not be balanced in the case of unequal current division; con- sequently, loops E and F shall be as made as small as possible. Loops
40、E and F will i B. Resulting current loops for circuit in A. SH 12234 FIGURE 7. Folded arrangement for a disconnect switch boxre 12 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DOD-STD-2 145 ( Sii) 1 June 1983 T T AreaA=AreaB=AreaC- Area D Area E =
41、 Area F = Area G :i fAreaH-Area1 A. Circuit for contactor panel with a folded arrangement. A C 1L 11 B. Resulting current loops for circuit in A. Net magnetic moment for loops A, B, C and D is equal to zero . regardless of equal current division between the tp outer conductors; similarly for current
42、 loops E, F and G. Loops H and I will not be balanced in the case of unequal current division; con- sequently loops H and I shall be made as mall as possible. 3 SH 12235 FIGURE 8. Folded arrangement for a contactor panel. 13 c) _. Provided by IHSNot for ResaleNo reproduction or networking permitted
43、without license from IHS-,-,-DOD-STD-2345 b3 7797733 0032632 3 Arrangement type DOD-STD-2145(SH) APPENDIX 1 June 1983 Flux density, nanotesla (UT) COMPA Folded Crisscross I 60 . 1220 N APPENDIX F EFFECTIVENESS ED AND CRISSCROSS ARRANGEMENTS FOR DISCONNECT SWITCH BOXES FF 10. GENERAL 10.1 Scope. This
44、 appendix illustrates the comparative effectiveness of fol- ded and crisscross arrangements for disconnect switch boxes. 20. REFERENCED DOCUMENTS Not applicable. 30. DEFINITIONS Not applicable. 40. GENERAL REQUIREMENTS Not applicable. 50. DETAILED REQUIREMENTS 50.1 Compared arrangements. Figure 9 il
45、lustrates the folded and criss- cross arrangements that are compared to the stray magnetic field they create. The dimensions are arbitrarily chosen. taken to be 1000 amperes (A). The current loops are shown as rectangular in shape (or very nearly rectangular) and the areas are figured as if they wer
46、e rectangular. crisscross (loops E to H on figure 10) have been omitted since these can be made so small in area that their magnetic field should be negligible. In all cases, the total current is In the crisscross arrangement, the four current loops in the 50.2 Comparison for equal current division
47、between outer conductors. For current equally dividd between the two outer conductors (that ia, each outer conductor carries 500 A while the center conductor carries 1,000 A), the maximum values of the vertical component of the magnetic field in a plane 6 meters below the centers of the two arrangem
48、ents are as indicated in table I. TABLE I. Equal division of current (500 amperes in each outer conductor). 14 I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-._ DOD-STD-2245 bL a 97777LL 0022633 5 Arrangement type Folded Crisscross DOD-STD-2145( SB) APPENDIX 1 June 1983 Flux density (nT) 700 1300 50.3 Comparison for unequal current division between outer conductors. For current unequally divided between the two outer conductors (that is, one Arrangement type Folded Crisscross outer conductor carrie
