The hottest registered safety engineer in 2006 pre

2006 Certified Safety Engineer preparation: common sense of power safety test questions

1. What kinds of equipment can be charged to extinguish a fire in the event of a fire in electrical equipment

answer: the control principle of 1211 dioxygen is relatively simple. Carbon tetrachloride dry powder (answer 2 is correct)

2. According to the frequency of electric shock accidents, which months of the year are the most concentrated

answer: from June to September

3. What is the maximum safe voltage

answer: 42 volts

4. How much is the safe DC current through the human body

answer: 50ma

5. How much is the AC safety current through the human body required to constantly challenge the limit

answer: 10ma

6. What should be done first in electric shock emergency rescue? Then what happens immediately

answer: electric shock rescue; Artificial respiration

7. How many protective devices are there in our factory to prevent direct lightning strikes

answer: lightning rod; Lightning protection; Lightning eliminator

8. When the wire is grounded, the closer the human body is to the grounding point, the higher the step voltage is, the farther the distance is, and the lower the step voltage is. Generally, the step voltage can be regarded as zero

A: within 10m, B: beyond 20m, C: beyond 30m

answer: B

9. Low voltage electric test pens are generally suitable for AC and DC voltages below () v

a:220 b:380 c:500

answer: c

10. The anti electric shock measures to be taken for the power connection of lighting facilities at the construction site are ()

a: wear insulating gloves B: cut off the power supply C: stand on the insulating board

answer: b

11. Whether the person who is shocked can be saved depends on ()

a: the way of electric shock B: the size of human body resistance

c: the level of electric shock voltage D: can you get rid of the power supply and implement emergency rescue as soon as possible

answer: d

12. What is the main thing to do to eliminate static electricity on the pipeline

answer: grounding

13. What is safety voltage

answer: under various environmental conditions, when the human body contacts an electrified body with a certain voltage, and no damage occurs to its various tissues (such as skin, heart, viscera, respiratory organs, nervous system, etc.), this voltage is called a safe voltage

14. What are the main factors that affect the degree of injury of current to human body

answer: the main factors are: the size of the current, the resistance of the human body, the length of the power on time, the frequency of the current, the level of the voltage, the way of the current, and the condition of the human body

15. How many hot starts are allowed in the hot state when the running motor is stopped and then started? How many consecutive starts are allowed under cold conditions? Answer: once; 2~3 times

16. For electric mechanical equipment used in construction, the protective measures that should be taken are

answer: protective neutral connection must be adopted, and at the same time, grounding should be repeated

17. What are the two parts of electrical safety measures

answer: organizational and technical measures

18. What are the main methods to disconnect from the low-voltage power supply

answer: (1) cut off the power supply; (2) Cut off the power cord; (3) Pull the power cord

(4) pull away the person with electric shock; (5) Take corresponding rescue measures

when taking the above measures, pay attention to the use of insulating tools that meet the corresponding voltage level

19. What is the sequence of switching on the disconnector during power transmission

answer: close the bus side first and then the line side after all are completed and put into operation

20. Can the knife switch of the power distribution box be opened with load

answer: No

21. What kind of electric tools must be used when using hand-held or mobile electric tools in places with explosion and fire hazards

answer: there are explosion-proof measures

22. How many volts of safety voltage should be used when using portable electric appliances or lights in wet workplaces or metal containers

answer: 12V

23. Can you press the stop button immediately when the motor is tested? Why

answer: No. The starting current is 6~7 times of the rated current, and the switch will be burnt out if the machine is shut down immediately

24. Most motors in our factory are explosion-proof motors. What is the general explosion-proof grade

answer: diibt4

25. Is the explosion-proof motor in our factory waterproof

answer: no

26. When the process load does not reach the rated load, the motor will not be overloaded, right? Why

answer: No. Medium change, pump failure and motor failure will all lead to overload