1、NIL-N-Zq738 66 = 7797706 04117756 5 M - - - _L /NON-MEASUREMENT SENSITIVE MIL-M- 24738 (SH) 11 January 1990 MILITARY SPECIFICATION MONITORS, HIGH TEMPERATURE MOTOR PROTECTION This specification is approved for use by the Naval Sea Systems Command, Department of the Navy, and is available for use by
2、all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scone. This specification establishes the design, performance, and test requirements for the motor thermal protection systems to be used in 60-hertz (Hz) and 400-Hz motors. 1.2 Protection system. The motor protection system cons
3、ists of multiple thermistors installed in the motors and a monitor located at the motor terminal box. 1.3 Classification. Monitors and thermistors shall be classified as specified in 3.3.i and 3.3.2. 2. APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 SDecifications. standards, and handbooks. Th
4、e following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto
5、, cited in the solicitation (see 6.2). SPECIFICATIONS FEDERAL PPP-F-320 - Fiberboard; Corrugated and Solid, Sheet Stock (Container Grade), and Cut Shapes. Beneficial comments (recommendations, additions, deletions), and any pertinent data which may be of use in improving this document should be addr
6、essed to: Commander, Naval Sea Systems Command, SEA 5523, Department of the Navy, Washington, DC 20362-5101 by using the self -addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AYSC NjA FSC 6625 DiSTRIMJTION STATEMENT A. Approv
7、ed for public release; distribution is unlimited, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MILITARY MIL- S - 901 MIL-E-917 MIL-E-2036 MIL-P-15024 MIL-P-15024/5 MIL-E-17555 MIL-L-19140 - Shock Tests, H.I. (High Impact) Shipboard Machinery, Equi
8、pment, and Systems, Requirements for. - Electric Power Equipment, Basic Requirements (Naval Shipboard Use). - Enclosures for Electric and Electronic Equipment. - Plates, Tags and Bands for Identification of - Plates, Identification. - Electronic and Electrical Equipment, Accessories, and Provisioned
9、 Items (Repair Parts): Packaging of. Equipment. - Lumber and Plywood, Fire-Retardant Treated. STANDARDS FEDERAL FED-STD-313 - Material Safety Data, Transportation Data and Disposal Data or Hazardous Materials Furnished to Government Activities. MILITARY MIL-STD-108 MIL-STD-167-1 MIL-STD-202 MIL-STD-
10、461 MIL-STD-740-1 MIL-STD-740-2 MIL-STD-810 MIL-STD-1285 MIL-STD-1399, Section 300 - Definitions of and Basic Requirements for Enclosures for Electric and Electronic Equipment. - Mechanical Vibrations of Shipboard Equipment (Type 1.- Environmental and Type II - Internally Excited). Component Parts,
11、Requirements for the Control of Electromagnetic Interference. - Airborne Sound Measurements and Acceptance Criteria of Shipboard Equipment. - Structureborne Vibratory Acceleration Measurements and Acceptance Criteria of Shipboard Equipment. - Environmental Test Methods and Engineering Guidelines. -
12、Marking of Electrical and Electronic Parts. - Interface Standard for Shipboard Systems Electric - Test Methods for Electronic and Electrical - Electromagnetic Emission and Susceptibility Power, Alternating Current, (Metric) (Unless otherwise indicated, copies of federal and military specifications,
13、standards, and handbooks are available from the Naval Publications and Forms Center, (ATTN: NPODS), 5801 Tabor Avenue, Philadelphia, PA 19120-5099.) 2.1.2 Other Government documents. drawings. and Dubiications. The following other Government documents, drawings, and publications form a part of this
14、document to the extent specified herein. are those cited in the solicitation, Unless otherwise specified, the issues 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-DEPARTMENT OF LABOR, OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION (OSHA) Code of F
15、ederal Regulations (CFR) 29, Part 1910.1200 - Occupational Safety and Health Standards. (Application for copies should be addressed to the Occupational Safety and Health Administration, Office of Publications, 200 Constitution Avenue, N.W., Room N3101, Washington, DC 20210.) 2.2 Non-Government Publi
16、cations. The following document(s) form a part of this document to the extent specified herein. Unless otherwise Specified, the issues of the documents which are DOD adopted are those listed in the issue of the DODISS cited in the solicitation. Unless otherwise specified, the issues of documents not
17、 listed in the DODISS are the issues of the documents cited in the solicitation (see 6.2). NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA) ICs 1 - General Standards for Industrial Controls and Systems. ICs 2 - Standards for Industrial Control Devices, Controllers and (DoD adopted) Assemblies. (
18、DoD adopted) (Application for copies should be addressed to the National Electrical Manufacturers Association, 2101 L Street, N.W., Suite 300, Washington, DC 20037.) (Non-Government standards and other publications are normally available from These documents also the organizations that prepare or di
19、stribute the documents. may be available in or through libraries or other informational services.) 2.3 Order of Drecedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, sup
20、ersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection (see 6.4) in accordance with 4.4. 3.2 Svstem requirements. The system shall monitor electrical m
21、otor temperatures and interface with existing motor switching and control functions to provide automatic shutdowns when conditions warrant. 3.3 Construction. The monitor, a solid state circuit with a plug-in relay, shall be in accordance with MIL-E-917, and the requirements of this specification. If
22、 any requirement specified herein conflicts with the requirements of MIL-E-917, the requirements of this specification shall govern. specified herein. All material shall be as 3.3.1 Thermistors, Thermistors shall be as specified in 3.3.1.1 through 3.3.1.4. 3 Provided by IHSNot for ResaleNo reproduct
23、ion or networking permitted without license from IHS-,-,-3.3.1.1 Tpe. Thermistors shall be positive temperature coefficient (PTC) type with a temperature coefficient of resistance at the switch point region of no less than 15 percent per degree Celsius (OC). Type I thermistors are for use with motor
24、 windings and type II are for use with motor bearings (see figures 1 and 2). 3.3.1.2 Ratinq. Thermistor switch points shall correspond with the motor insulation class ratings of MIL-E-917: 105“C, 135“C, 175“C, and 200C (see 6.2) 3.3.1.3 Thermistor leads. The thermistor leads shall be flexible strand
25、ed Type I and II thermistors shall be constructed as shown on figures 1 and copper of not less than size AWG 24 wire with an insulation rating of at least 600 volts, 2. 3.3.1.4 Markinq. The thermistor shall be marked to indicate the switching temperature rating in degrees Celsius, and shall satisfy
26、the requirements of MIL-STD-1285. 3.3.2 Thermal monitor through 3.3.2.24. Thermal monitors shall be as specified in 3.3.2.1 . 1 3.3.2.1 Enclosures. enclosure for type I monitors, internal mounting, shall be constructed to provide the necessary electrical isolation from adjacent components and electr
27、ical connections, while keeping the size to a minimum. Type II monitors shall be of metal construction suitable for marine applications and shall meet the requirements of MIL-STD-108 and MIL-E-2036. Provisions shall be made for securely mounting the monitor, 3.3.2.2 Painting. Parts not fabricated of
28、 a corrosion-resisting material or having a corrosion-resistant treatment as specified in MIL-E-917, except for semi- conductors, shall be painted as specified in MIL-E-917, enamel shall be applied to the outside of the enclosure. permitted for marks or scratches due to factory handling. Only one co
29、at of gray Touching-up will be 3.3.2.3 Duty. The monitor shall sense the motor temperature continuously and shall, at the temperature set point, activate a minimum of one set each of normally closed and normally open contacts. 3.3.2.4 Weight. The weight of the monitor shall be not greater than 5 pou
30、nds, 3.3.2.5 Dimensions. The enclosure dimensions of the monitors shall be not greater than 4.0 by 3.5 by 3.75 inches. 3.3.2.6 Mounting, The monitor shall be attached to a plate for mounting. The plate shall The dimensions of the plate shall be 5.0 by 2.5 by 0.25 inches. have 4 holes, 0.31 inches di
31、ameter, placed symmetrically 1.5 by 4.25 inches apart. 3.3.2.7 Finish. The finish shall be smooth and free of blurs, corrosion, and sharp corners. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.3.2.8 Safety. The monitor shall meet the safety req
32、uirements of MIL-E-917. 3.3.2.9 Hazardous materials. There shall be no use of hazardous materials except where no suitable substitute is available and prior approval has been obtained. when used for its intended purpose. referred by the contracting activity to the appropriate departmental medical se
33、rvice who will act as an advisor to the contracting agency. The material shall have no adverse effect on the health of personnel Questions pertinent to this effect shall be 3.3.2.9.1 Material safety data sheet (MSDS). The contracting activity shall be provided a material safety data sheet at the tim
34、e of contract award. shall be provided in accordance with the requirements of FED-STD-313. shall be included with each shipment of the material covered by this specification (see 6.7). The MSDS The MSDS 3.3.2.10 Ventilation. Cooling of the monitor shall be natural convection from the enclosure. 3.3.
35、2.11 Humiditv. The monitor shall meet the requirements of MIL-STD-810 for humidity. 3.3.2.12 Warm-UD. The monitor shall perform as specified herein immediately upon being energized. 3.3.2.13 InDut. Input terminals shall be provided for connection of six thermistors in common leg configuration tlpara
36、llel“. 3.3.2.14 Automatic reset. The monitor shall have a factory selectable automatic reset of latching mode of operation. 3.3.2.15 Ambient tenmerature. The monitors shall operate in an ambient temperature range of O to 50C with short term, emergency capability to 70C. 3.3.2.16 Hysteresis. The moni
37、tor shall have a resistance trip to resets“ hysteresis of greater than 250 ohms to prevent cycling of the monitor. 3.3.2.17 Fail safe. The monitor shall operate (fail safe) on the short- circuiting of the thermistor input by a resistance of 10 ohms or less. 3.3.2.18 Output. The output of the monitor
38、 shall operate a relay mounted within the monitor enclosure. normally open and one pair of normally closed contacts. The relay shall be provided with one pair of 3.3.2.19 Monitor excitation, The monitor excitation shall be factory adjustable for single phase, 120 volts, 60 or 400 Hz, and shall opera
39、te with type I or II powers as specified in MIL-STD-1399, section 300. 3.3.2.20 Monitor relay. The monitor relay contacts shall operate a 5 ampere, 120 volt alternating current (Vac) or 28 volt direct current (Vdc) control circuit. 5 Provided by IHSNot for ResaleNo reproduction or networking permitt
40、ed without license from IHS-,-,-.-_ _ - _-. MIL-M-24738 bb 777970b OLiL77bL 7 W MIL-M-24738(SH) 3.3.2.21 Monitor switching temDerature. The monitor shall switch within a plus or minus 5C band af the thermistor switching temperature. 3.3.2.22 Electrical isolation. The monitor shall provide electrical
41、 isolation between the thermistor input, the monitor excitation, and the monitor output, and may operate with one of the thermistor input leads grounded. 3.3.2.23 Current. The monitor circuiting shall limit the monitoring current supplied to the thermistor to less than 2 milliamps to eliminate self-
42、heating. 3.3.2.24 Noise limits. The monitor shall not exceed noise limits in accordance with MIL-STD-740-1 and MIL-STD-740-2. 3.3.3 Markinrrs. Markings shall be in accordance with 3.3.3.1 through 3 .3,3.1.2, 3.3.3.1 Connection diagram and identification Dlates. Connection diagram The plates shall be
43、 brass or corrosion-resistant steel not less and identification plates shall be in accordance with MIL-P-15024 and MIL-P-15024/5. than 0.030 inch in thickness and marked by etching, engraving, stamping, or photo process. The marking shall be not less than 0.003 inch deep. 3.3.3.1.1 Connection diagra
44、m. Each monitor shall be provided with a connection diagram plate mounted on the inside surface of the front cover. 3.3.3.1.2 Identification Dlate. Each monitor shall be provided with an identification plate mounted on the outside of the front cover. identification plate for the complete equipment a
45、ssembly shall contain the information as shown on figure 3. The 3.4 Performance characteristics. The performance requirements listed in The input power for the monitor shall be 120 Vac, this section are designed to provide basic information on the electrical performance of the monitor. single phase,
46、 60 or 400 Hz provided by an ungrounded supply. The monitor relay provides the capability of interrupting the control power to the motor once the motor winding temperature has reached the temperature rating of the insulation class. temperature as specified in 3.3.1.2. The thermistor provides the sig
47、nal determined by its switch point 3.4.1 Thermistor dielectric. Thermistor dielectric strength shall be not less than 100 megohms (see 4.6.2). 3.4.2 Thermal resaonse rate. Thermistors shall have a thermal response not exceeding 5 seconds to reach a resistance of 2600 ohms (see 4.6.3). 3.4.3 High Pot
48、ential. The monitor when subjected to a high potential test for resistance shall show no evidence of failure (see 4.6.4). 3.4.4 Environment, The monitor when operated with ambient temperature varied from O to 50C inclusive shall not deviate from the rated thermistor switch point by more than plus or
49、 minus 5C (see 4.6.5). 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.4.5 Electromagnetic interference. The monitor when tested for susceptibility to electromagnetic interference shall operate with immunity (see 4.6.6). 3.4.6 Svstem operation. The motor thermal monitor systems shall respond to an over-temperature condition within plus or minus 5C of the rated thermistor switch point.
