This specification covers monitoring devices (monitors) for the automatic detection and signaling of low insulation resistance values in idle electrical motors or generators, or both. Monitors are intended for permanent installation in both existing or new panels and controller enclosures designed for marine application. These insulation resistance monitors shall be classified in four types: Type I are alternating current generator monitors, Type II are alternating current generator monitors, Type III are direct current motor monitors, and Type IV are direct current generator monitors. The enclosure materials used in the construction of the monitors are to be flame-retardant and the current carrying terminals shall be made of corrosion resistant material. The monitors shall isolate their measuring circuit from the line voltage, while the motor is operating, by the use of an integral isolating relay. In the design of these monitors, environmental factors shall be considered: operating temperature range, sealing, inclination, humidity, and vibration. Also, the monitor relays, voltage characteristics and operating accuracy shall be considered in the design of these monitors. Each monitor shall be subjected to the following: visual and mechanical examination and operational test.1.1 This specification covers monitoring devices (monitors) for the automatic detection and signaling of low insulation resistance values in idle electrical motors or generators, or both.1.2 Monitors are intended for permanent installation in both existing or new panels and controller enclosures designed for marine application.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.1.4 The following safety hazards caveat pertains only to the test method described in this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

4.1 The selection criteria is to be applied for uses of (1) new motors and (2) replacement motors.4.2 For the selection of new or replacement motors, this practice defines the choice criteria in terms of the ordering data below.AbstractThis guide provides the required basic ordering information for low voltage (1000 VAC or less, and up to and including motors of 500 hp) general-purpose (GP), commercial, universal, small and medium sized alternating current electric motors intended to drive common shipboard mechanical machinery such as fans, blowers, centrifugal and screw pumps. This guide does not address the ordering information for special-purpose (SP) motors, definite-purpose motors (for example, cryogenic service), or motors for use in hazardous (classified) locations as defined by the National Electrical Code (NFPA 70). The ordering checklist shall provide the following minimum information: electrical input; speed; power; enclosure; duty cycles; ambient temperature; insulation class; design class; service factor; drive method; mounting arrangement; mounting flange (end shield); rotation; motor conduit box location; closed-coupled; efficiency; and other special requirements.1.1 This guide covers the required basic ordering information for low voltage (1000 VAC or less) general-purpose, commercial, universal, small-, and medium-sized alternating current electric motors for shipboard use, up to and including motors of 500 hp.1.2 The electric motors covered by this guide are general-purpose (GP) motors intended to drive common shipboard mechanical machinery such as fans, blowers, centrifugal and screw pumps.1.3 This guide is not intended to be used to order special-purpose (SP) motors or definite-purpose motors (for example, cryogenic service) or motors for use in hazardous (classified) locations as defined by the National Electrical Code (NFPA 70).1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车