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 theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2014 SAE InternationalAll rights reserved. No part of this publi
3、cation may 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/J277_201407SURFACE VEHICLERECOMMENDED PRACTICEJ277 JUL2014Issued 1971-12Revised 2014-07Supers
5、eding J277 AUG2010Maintenance of Design Voltage - Snowmobile Electrical SystemsRATIONALEUpdated the procedure, to reduce testing and cover all normal operating limits. Also, the table was updated to reflect new testing procedure. FOREWORDThis SAE Recommended Practice is intended as a guide toward st
6、andard practice, but may be subject to frequent change to keep pace with experience and technical advances. Hence, its use where flexibility of revision is impractical is not recommended.1. SCOPEThis SAE Recommended Practice provides test methods and requirements for maintenance of design voltage in
7、 snowmobile electrical systems. It pertains to both battery-equipped and battery-less systems.2. REFERENCESThere are no referenced publications specified herein.3. SAMPLES FOR TESTSamples submitted for laboratory test shall be representative of the systems as regularly manufactured and marketed.Each
8、 sample shall include not only the electrical system, but also accessory equipment necessary to operate it in the normal manner.4. TEST APPARATUS4.1 VoltmeterAlternating current (AC) or direct current (DC), as required, capable of 2% accuracy of the measured reading. For AC measurements, either a tr
9、ue RMS voltmeter is required or the AC and DC components of the AC waveform must be measured separately and added algebraically as follows in Equation 1:Vtrue rms=square root(Vdc2+Vac2)(Eq. 1)For AC measurements, the voltmeter must have a minimum crest factor of 3.4.2 AmmeterSAE INTERNATIONAL J277 R
10、evised JUL2014 Page 2 of 4DC, capable of 2% accuracy of the measured reading.4.3 TachometerMeans of measuring engine rpm within 3%.5. TEST PROCEDURE5.1 Preliminary Instruction5.1.1 If snowmobile is battery equipped, install a fully charged original equipment battery.5.1.2 If snowmobile is battery eq
11、uipped, install the ammeter in series with the battery such that it indicates negative current for discharge and positive current for charge conditions. Do not install the ammeter in series with the electric starter motor.5.1.3 Voltmeter Installation5.1.3.1 Install the voltmeter(s) across the lamp t
12、erminals. For the purpose of this document, the terminal voltages are designated as follows:a. V1 - Headlamp low beam terminals.b. V2 - Headlamp high beam terminals.c. V3 - Tail lamp terminals.d. V4 - Stop lamp terminals.5.1.3.2 Take the required voltage readings simultaneously. If this is not possi
13、ble, record the average of three consecutive readings that are within 1 V of each other.5.1.4 Engine RPM5.1.4.1 Do not use a tachometer operating from the alternator signal unless: it is standard equipment in the system being tested, or it affects the systems output voltage less than 0.5%.5.1.5 Syst
14、em OperationVerify proper operation of all lamps, switches, and associated equipment both before and after the test is completed.5.1.6 Optional Accessories DefinitionOptional accessories are all electrical loads that come standard with the vehicle that can be switched off and can usually be turned o
15、n for more than 1 min, including but not limited to the front and rear heated grips, heated lever, heated seat,and cooling fan.Head lamp, tail lamp, stop lamp, and manufacturers separately sold accessories are excluded. All other factory installed loads that are presently connected to the vehicle ar
16、e not considered as accessory and must be connected at all times.5.1.7 Data SheetPrepare data sheet to record the voltage measurements indicated in Table 1 and the rpm recorded in 5.2.2.2.SAE INTERNATIONAL J277 Revised JUL2014 Page 3 of 4TABLE 1 - SWITCH POSITION FOR VOLTAGE MEASUREMENTSwitch Positi
17、ons Measure Voltage at: Engine RPMHeadlamp LowHeadlamp HighTail LampStop LampPowered Accessory(s)V1 V2 V3 V41Idle -highest loadOXXO X2Idle lowest loadXOXO O3Clutch EngagementOXXO X4Rated highest loadOXXX X5Rated lowest loadXOXO ONOTE: X - Switch in “ON“ position V1 - Headlamp low beam terminal to gr
18、ound = No measurement requiredO - Switch in “OFF“ position V2 - Headlamp high beam terminal to groundV3 - Tail lamp terminal to groundV4 - Stop lamp terminal to ground5.2 Data Recording5.2.1 Record the voltage measurements for the various switch positions and rpm as indicated in Table 1.5.2.1.1 Idle
19、 rpm equals manufacturers recommended idle rpm.5.2.1.2 Clutch engagement rpm equals the rpm of initial clutch engagement (for systems not using a centrifugal clutch, run the engine at an rpm equivalent to 40% of top speed in top gear).5.2.1.3 Rated rpm equals the engine rpm at maximum bhp, as instal
20、led in the snowmobile.5.2.2 RPM for “0“ Ammeter ReadingNO-TE: If the battery is not in the charging state at idle, the test as described in 5.2.2 must be performed.For battery-equipped systems only.5.2.2.1 Switch headlamp to high beam.5.2.2.2 Record the engine rpm at which the ammeter reads “0“.5.2.
21、3 Systems with Two or More Headlamps5.2.3.1 Simulate a field lamp failure.5.2.3.2 Repeat 5.2.1.SAE INTERNATIONAL J277 Revised JUL2014 Page 4 of 46. TEST LIMITS6.1 Except as provided in 6.1.1, record all measurements in 5.2.1 and 5.2.3.2 between 80 and 120% of the rated lamp design voltage.6.1.1 At i
22、dle rpm, the lamp voltages (V1, V2, V3, and V4 are to be between 40 and 120% of the rated lamp design voltage.6.2 Do not use or record the rpm of 5.2.2.2 if it is greater than the manufacturers clutch engagement rpm.7. TEST CONDITIONSCondition the snowmobile before testing. Snowmobile conditioning c
23、onsists of either running the snowmobile at the manufacturers recommended idle rpm for 5 min, or soaking the snowmobile for 2 h at a temperature of no less than 10 C.8. NOTES8.1 Marginal IndiciaA change bar (l) located in the left margin is for the convenience of the user in locating areas where tec
24、hnical 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 documents that contain editorial changes only.PREPARED BY THE SAE SNOWMOBILE TECHNICAL COMMITTEE
