1、SAE ARPx59YD 90 8357340 0059373 9 AEROSPACE RECOMMENDED The Engineering Society aA =For Advancing Mobility Land Sea Air and Space INTERNATIONAL 400 Commonwealth Drive, Warrendale, PA 15096-0001 PRACTICE Submitted for recognition as an American National Standard FUEL PUMP THERMAL SAFETY DESIGN REV. S
2、E ARP594 D Issued 1959-02-01 Revi sed 1990-07-1 1 1. SCOPE: These recommendations cover only those design factors which mlght cause the pump motor or pump housing to act as an autogenous or spark-ignition source for explosive fuel vapors within the airplane tank. 2. PURPOSE: This Aerospace Recommend
3、ed Practice (ARP) recommends fuel booster pump design requirements commensurate with the presently known state-of-the-art, relating to the prevention of autogenous ignition of explosive fuel vapors and the conf i nement of autogenous or spark-i ni ti ated f 1 ames by means of flame-suppressing devi
4、ces. 3. GENERAL RECOMMENDATIONS: 3.1 Design should be such that under abnormal conditions, such as dragging rotor, locked rotor, internal shorts, etc., the external case temperature does not at any time exceed 400F (204C). 3.2 Any device or design expedient used to accomplish 3.1 should be such that
5、 it performs its function without producing an open spark in any volume space which contains fuel vapors or any other material susceptible to-spark igni tion. 3.3 Any device or system design expedient used to accomplish 3.1 should be single-action, that is, nonresettable, or resettable within the co
6、ntext of 3.9 and 5.9. 3.4 Requirements for any device or design expedient to accomplish 3.1 should not material ly affect the normal operational re1 iabi 1 i ty of the pump. SAE Technical Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sci
7、ences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.“ SAE reviews each technical report at least every five years at which time it may be reaffir
8、medlrevised, or cancelled. SAE invites your written comments and suggestions. Copyright 1990 Society of Automotive Engineers, Inc. All rights reserved. Printed in U.S.A. COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesElm - ARP594 Revision D
9、 P I) B The following means of preventing electric motor driven fuel booster pumps from becoming ignition sources in aircraft fuel tanks have been considered in the preparation of this ARP. the various means considered. Appropriate comments are made with respect to 4.1 Motor esi gn Approach: 4.1.1 M
10、otor Burnout: A motor that will burn out in a sufficiently short period of time, if necessary, to limit the maximum pump case temperature to the recommended value. NOTE: This method is not recommended, as it does not meet the requirements of 3.2 and imposes a severe quality control problem, - 3,5 Ve
11、nts, slots, passages, etc., incorporated in the pump or motor housing, through which flame can travel to external fuel or vapor containing areas, should be capable of suppressing flame under all normal and abnormal conditions. Explosion-proof testing procedures should consider the pump internal and
12、external surface temperatures, including the flame traps at the local peak values obtained (such as during locked-rotor tests), and with fuel cell and external ambient temperatures as specified in the detail specifications for the pump. 3.6 Any device or design expedient used to accomplish 3.1 for f
13、uel-cooled motors is itself subject to fuel cooling. The accuracy of devices used to accompl ish 3.1 is general ly dependent upon how accurately these devices sense motor temperature. If these devices are being cooled by fuel while they are being heated by the motor, their accuracy can be seriously
14、affected. Consequently, isolation of these devices,from the cooling effect of fuel should be a design consideration. 3.7 -The motor housing design should include provisions to prevent arcing from the motor windings to the motor housing in event of winding damage. Electrical arcs from the windings to
15、 the motor housing can produce local hot spots and may burn through the housing if high arc energy is available and sufficient differentia? pressure exists to cause the fused metal to flow, 3.8 It is recommended that a minimum clearance of 0.100 in (2.54 mm) be provided between motor windings and th
16、e motor housing for 200 VAC, 400 Hz, three-phase motors. 3.9 Certain circumstances, such as extended dry running in an elevated temperature environment, may necessitate special measures to limit temperature ri se, which may otherwise become excessive even in normal operation. An approach to these si
17、tuations is the use of a resetting three-phase thermostatic switch in combination with three single-phase fusible element switches. During the gradual temperature rise attendant to normal operation, the thermostat, having a lower trip point, cycles off and on at temperatures chosen to suit the appl
18、ication, conditions, when the temperature rise is too rapid for satisfactory response by the thermostat, the fuse links actuate to permanently remove the flow of power. Under abnormal 4, DESIGN CONSIDERATIONS: -2- COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Informat
19、ion Handling ServicesSAE ARPm594D 90 W 8357340 0054393 2 E 1= - ARP594 Revision D _ 4.1.2 Self-Limiting Motor: A motor which will be left on the power line without burning out or exceeding the recommended value of the pump case temperature. NOTE: This approach is not recommended because of size and
20、weight considerations. Further exploration into this type of design approach is advisable. 4.2 Thermal Cutoff Switches: These devices can, in general, be recommended with the stipulation that they be contained in a sealed enclosure because of explosion-proof considerations and that special emphasis
21、to 3.4 be considered. 4.2.1 Motor Protectors: 4.2.1.1 Three-phase, wye thermostat with heaters, resetting type. NOTE: Not acceptable, as it does not meet requirements of 3.3. 4.2.1.2 Three-phase, wye thermostat, with heaters, nonresetting. NOTE: Acceptable, but will not protect against internal moto
22、r faults. 4.2.1.3 Three-phase, six-terminal, line thermostat with heaters, resetting type. NOTE: Not recommended, as it does not meet requirements of 3.3. 4.2.1.4 Three-phase, six-terminal, line thermostat with heaters, nonresetting. NOTE: Recommended and adds some internal motor fault protection no
23、t provided in 4.2.1.2. 4.2.1.5 Three single-phase thermostats with heaters, nonresetting type. NOTE: Acceptable, provided they are connected in line side of motor and that motor will operate on two phases. possible two-phase operation may be necessary. Ground check for 4.2.2 Thermostats: 4.2.2.1 Thr
24、ee single-phase, line thermostats, nonresetting. NOTE: Acceptable, provided they are connected in line side of motor and that motor will operate on two phases. Ground check for possible two-phase operation may be necessary. 4.2.2.2 Three-phase, wye thermostat, resetting type. NOTE: Acceptable for du
25、al protection per 3.9, otherwise not recommended I as it does not meet requirements of 3.3, -3- COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling Services- SAE ARP*534D 30 8357340 0054334 4 EAE JCT ARP594 Revision D - 4.2.2.3 Three-phase, wye thermost
26、at, nonresetting type. NOTE: Acceptable, but does not protect against internal motor faults, 4.2.2.4 Six-terminal, line thermostat, resett ng type. NOTE: Acceptable for dual protection per 3.9, otherwise not recommended because it does not meet 3.3. 4.2.2.5 Six-terminal, line thermostat, nonresettin
27、g type. NOTE: Recommended and adds some internal motor fault protection not provided in 4.2.2.3. 4.2.3 Fusible Links: 4.2.3.1 Definition: opens the circuit by melting at a predetermined temperature. A metallic component that carries the load current and - NOTE: Acceptable, but extreme qual i ty cont
28、rol caution must be exerci sed in both manufacture and installation in the motor. Fusible links should be installed in such a manner that they unequivocally sense the temperature of the motor phase winding to which they are electrically connected. It is recommended that fusible links . be embedded i
29、n, or abutted against, the motor windings. 4.2.4 Remote Switching: 4.2.4.1 Definition: Thermostat, resetting type with a relay. NOTE: Not recommended, as it.does not meet requiremen 4.2.4.2 Thermostat, nonresetting type with a relay. NOTE: Recommended, but may have some effect on the re system, due
30、to the additional wiring required. s of 3.3. i abi ity of the 4.2.4.3 Thermocouple or thermistor with a relay, which is presently in system for a pump that is connected into the pumps electrical power system. NOTE: Not recommended, as both thermocouples and thermistors are by definition resettable w
31、ith zero dead band and do not meet 3.3. -4- COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesSAE ARP*594D 90 8357340 0054395 b = eA= - ARP594 Revision D 4.2.5 Fusible Element Actuated Snitches: 4.2.5.1 Definition: carrying element. A switch a
32、ctuated upon the melting of a nonload current NOTE: Acceptable, but extreme quality control caution must be exercised in both manufacture and installation of the devices in the motor to establish and preserve the hermeticity necessary to prevent fuel from reaching and degrading the fusible element.
33、These devices should be installed in such a manner that they unequivocally sense the temperature of the motor phase winding to which they are electrically connected. these devices be embedded in, or abutted against, the motor wi ndi ng . it is recommended that 5. PREPRODUCTION TESTS: Unless otherwis
34、e specified in the model specification, preproduction tests shall consist of all tests as listed for the type of device selected. The tests shall be conducted on a population of nine thermal protective devices of the type selected as shown below, and must be conducted essentially in the order listed
35、 for each device: a. Devices, Numbers 1 and 2 I (1) Dielectric strength 5.1 (not applicable to fusible link devices) (2) Contact resistance 5.2 (3) Vi bration 5.6 (Device Number 2 is used for 5.6.3 only) (4) Inrush current 5.7 (5) Contact resistance (6) Temperature endurance and shock 5.2 5*3 (7) Ac
36、tuation endurance 5.13 (Not -applicabie to fusible element devices) (8) Contact resistance 5.2 (9) Actuation temperature 5.8 (10) Reset temperature 5.9 (Not applicable to fusible element devices) -5- COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling S
37、ervicesSAE ARP*574D 90 8357340 005437b 8 W JCC ARP594 Revision D 5. (Continued): b. Device Number 3 (1) Dielectric strength (2) Contact resistance (3) Fuel resistance (4) Contact resistance (5) Acceleration (6) Shock (Not applicable to fusible link devices) - (7) Contact resistance (8) Actuation tem
38、perature c. Device Number 4 (1) Dielectric strength (2) Contact resistance (3) Fungus resistance (4) Humidity (5) (6) Contact resi stance (7) Actuation temperature (Not applicable to fusible link devices) Dielectric test at 75% voltage (Not applicable to fusible link devices) d. Devices, Numbers 5,
39、6, 7, 8, and 9 (1) Explosion proof. Each of the five units shall be used once only. 5.1 Dielectric Strength: 5.1 5.2 5.14 5.2 5.4 5.5 5.2 5.8 5.1 5.2 5.11 5.10 5.1 5.2 5.8 5.12 Dielectric strength test voltage of 1500 V (rms) at commercial frequency shall be applied for 1 min between terminals joine
40、d together and case. A dielectric strength test voltage of 1800 V (rms) may be applied for 1 s in lieu of the 1-min test. There shall be no evidence of breakdown. D D B COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesSAE ARPI594D 90 W 835734
41、0 0054377 T ARP594 Revision D s 5.1 (Continued): The test shall be conducted with a dry unit at room temperature. application of the voltage shall produce no appreciable Wansient overvoltages. Subsequent tests shall be conducted as shown, except that the voltages shall be reduced to 75% of those spe
42、cified. The 5.2 Contact Resistance (Terminal-to-Termina1 : 5.2.1 Test Equipment: 5.2.1.1 Low voltage output variable transformer power supply with sufficient current rating to supply the normal or rated current of the thermal protector. 5.2.1.2 AC voltmeter with an input impedance of 1 megohm or gre
43、ater and with several millivolt ranges suitable for the anticipated voltage drop across the thermal protector. 5.2.1.3 AC ammeter of suitable range for normal or rated current of the therma protector. 5.2.1.4 A series resistance may be used as needed. 5.2.2 Description of Test Setup: The thermal pro
44、tector and ammeter are connected in series with the load resistor across the output of the variable transformer power supply. All connecting wires should be of adequate size to carry the normal or rated current for the thermal protector. All connections should be soldered connections. The voltmeter
45、should be connected directly across the thermal protector, terminal-to-terminal, and adequately soldered. The variable transformer should be connected to the power lines through a switch. 5.2.3 Test Procedure: 5.2.3.1 Temperature-Sensitive-Only Devices (Such as 4.2.2 Et Sequence): 5.2.3.1.1 Test Met
46、hod: With the variable transformer set for zero output voltage, energize the variable transformer by means of the switch. Adjust the output of the transformer for normal or rated current through the ammeter and read the voltage drop across the thermal protector on the voltmeter. terminal-to-terminal
47、. the voltmeter reading divided by the ammeter reading. Calcuiate the contact resistance This resistance is expressed by the quotient of 5.2.3.1.2 Test Conditions: The test should be conducted at ambient room temperature. 5.2.3.1.3 Change in Resistance: Contact resistance, terminal-to-terminaT, shal
48、l not increase by more than 25% when test is repeated in the schedule. -7- COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesSAE ARPx594D 90 m 8357340 0054398 L *= EAE - ARP594 Revision D I 5.2.3.2 Motor Protectors (Temperature- and Current-Se
49、nsitive), such as 4.2.1: 5.2.3.2.1 Test method same as in 5.2.3.1.1. 5.2.3.2.2 Test conditions same as in 5.2.3.1.2, except that the device shall be immersed in an oil bath at ambient room temperature. 5.2.3.2.3 The change in resistance, terminal-to-terminal, shall be within the amount stated in the detail specification. 5.3 Temperature Endurance and Temperature Shock: 5.3.1 Purpose: protector under prolonged exposure to temperatures near the actuation temperature and under repeated thermal shock conditions, without causing the device to actuate or reset. not requi red. T
