判断 首字母汇 高级工(国外英文资料).doc

判断 首字母汇 高级工(国外英文资料) A: 1: wrong. According to abnormal work, the allowable voltage loss is primary to the low voltage cable section. 2: pair. The installer should be able to use the correct installation tools, spanner, pipe shall not be lengthened sleeve, extended arm, not instead of using hammer. 3: wrong. The equipment installed must be tested in accordance with the test items specified in the electrical test procedure, and the test can be used without qualification. 4: wrong. There is no need to strictly enforce the power delivery system during installation 5: yes. When installing explosion-proof equipment, it is necessary to protect the explosion-proof surface, not to use the equipment to do the work table, so as not to damage the equipment. After installation, it should comply with the explosion-proof performance requirements. 6: the manual parts of the equipment can be operated without special flexibility, and the closing of the switch contacts can be used. B: 1: pairs: a transformer can change the alternating voltage of a certain value to an alternating voltage of the same frequency and magnitude. 2: Yes. Transformer can change alternating current, change phase and change impedance besides changing alternating voltage. 3: Yes: BKD1-500/1140 (660) mine flameproof vacuum feed switch leak detection relay, after completion of action, press the reset button, vacuum feed switch allows closing. 4: Yes: semiconductor release device long delay over-current, setting range of rated current 0.4~1 times 5: wrong: semiconductor tripping device over-voltage protection device: feed switch UVW, any hatchback, respectively, access to the resistance device, when the power grid appears over-voltage, through the resistance capacitance absorption to eliminate over-voltage on the line of harm. 6: wrong: rake bucket type loader rake bucket return resistance, return roller speed is greater than the speed of the work cylinder. C: 1: to CPU is the core component of PLC, accepting the p