1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2008 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org AIR4365A AEROSPACE INFORMATION REPORT Issued 1994-12 Revised 2008-03 Superseding AIR4365 400 Hz Connection Aircraft Electrical Maintenance Procedures RATIONALE AIR4365 is being revised to reflect new diameters of rec
5、eptacle pins in Figure 1, in accordance with reference MS90362. In addition, the word “pin” was replaced with “socket” in several places throughout the document for descriptive accuracy. 1. SCOPE This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz elec
6、trical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces. 2. APPLICABLE DOCUMENTS The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The
7、applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and
8、 regulations unless a specific exemption has been obtained. 2.1 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. MS90362 (AN3114
9、) 110 Volt, AC, Aircraft Receptacle MS90328 (AN3430) Cable Assembly, External Electric Power, Aircraft, 115/200 Volts, 400 Hz MIL-C-7974 Cable Assemblies and Attachable Plugs, External Electrical Power, Aircraft Copyright SAE International Provided by IHS under license with SAENot for ResaleNo repro
10、duction or networking permitted without license from IHS-,-,-SAE AIR4365 Revision A - 2 - 3. PROBLEM The aircraft receptacle is configured to MS90362 (AN3114). The plug end of the cable from the 400 Hz external source is configured to MS90328 (AN3430). With todays widespread use of external 400 Hz s
11、ystems, plug and receptacle wear has increased, resulting in problems with the electrical connection. One or more worn or loose contacts in the connector can cause high contact resistance which results in a hot plug, in some cases a fire, or loss of a phase, or loss of control voltage (E & F) which
12、causes the aircraft to reject the external 400 Hz power. The plug presents the bigger problem because the combined grip of the sockets must be sufficient to prevent the plug from coming loose from the aircraft receptacle. This grip must be sufficient to support the weight of the plug and about 10 ft
13、 (3.05 m) of cable. In the case of wide body aircraft, the receptacle on board the aircraft should have the pin diameters checked. Military Standard MIL-C-7974 specifies 80 lb (356 N) 20 lb (89 N) insertion force and maximum 100 lb (445 N) extraction force. In an effort to establish procedures for c
14、hecking the plug and receptacle, several methods have been tried. Tests conducted by various manufacturers and airlines on plugs in service show mixed results. If you adopt the 60 lb (267 N) to 100 lb (445 N) insertion and extraction forces, it is reasonable to assume that 15 lb (67 N) to 25 lb (111
15、 N) on each socket would indicate a good contact. Experience shows that 4 sockets x 25 lb (111 N) results in a total force required of over 100 lb (445 N). This total force has not been fully investigated but could be as high as 150 lb (667 N) due to misalignment. Some tests have shown four sockets
16、that measured low individually but show high collective readings because of misaligned contacts. 4. RECOMMENDATION While the aforementioned results may not show a reliable test method, the following procedures are recommended to increase plug and receptacle life and safety: 4.1 Receptacle The indivi
17、dual pin diameters and alignment shall be checked on a schedule basis. Pin diameters should be as shown in Figure 1 using the tools shown in Figure 2. 4.2 Plug Since testing the total insertion and extraction forces would probably require two people or a special fixture because of the force involved
18、 (100 lb (445 N), we recommend that a tool for checking individual sockets and pins be used as shown in Figure 2. The forces and procedures are as shown in Figure 2. 4.3 Summary These recommended checks should reduce the incidence of failure in these two components. In addition, the following recomm
19、endations for proper maintenance and handling will extend plug life. Keep the sockets clean using a 45 caliber nylon bore cleaning brush for power contacts and a 32 caliber brush for control contacts When disengaging the plug, pull smoothly with a gentle rocking motion Grasp only the plug body when
20、removing the plug Make every attempt to not let the plug contact the ramp surface Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR4365 Revision A - 3 - The receptacle face and pins should be c
21、leaned before checking Inspection Frequency: As routinely scheduled New Minimum Diameter Diameter* Phase Pin 0.436 in (11.07 mm) 0.432 in (10.97 mm) Control Pin 0.311 in ( 7.90 mm) 0.307 in ( 7.80 mm) *Note: When the pins are worn to the minimum diameter (loose) or the pins are bent the receptacle s
22、hould be replaced. FIGURE 1 - AIRCRAFT RECEPTACLE Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR4365 Revision A - 4 - Notes: 1. Tools for performing this function are available from commerci
23、al sources. 2. The plug contacts should be cleaned per figure 3 before testing. 3. Recommended frequency maximum 4000 insertions. 4. Extraction force to be minimum 15 lb (66.7 N) per phase socket. 5. Extraction force to be minimum 3 lb (13.3 N) per control socket FIGURE 2 - WEAR GAUGE FOR PLUG AND R
24、ECEPTACLE Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR4365 Revision A - 5 - 5. NOTES 5.1 A change bar (l) located in the left margin is for the convenience of the user in locating areas wh
25、ere technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in docum
26、ents that contain editorial changes only. PREPARED BY SAE SUBCOMMITTEE AGE-2C, VEHICLE MAINTENANCE & AIRCRAFT SERVICING OF COMMITTEE AGE-2, AIR CARGO & AIRCRAFT GROUND EQUIPMENT & SYSTEMS Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
