Mine maintenance fitter intermediate class examination questions
One: Single choice
1, (c) shall be made of corrosion-resistant steel plate with an area of not less than 0.75 m.
A. auxiliary grounding electrode
B. Local grounding electrode
C. main grounding electrode
2, when using the coal plough, working face at least every () should be installed at any time to stop the coal plough and scraper conveyor device, or install a device to send signals to the coal plough driver.
0.40 m
B.35m
About 30 meters
Answer c
3, 380V power supply line, the allowable value of motor terminal voltage deviation is ().
A. 19V
B.33V
C.39V
D.60V
Answer a
4, underground lighting and signal device, comprehensive protection device should be adopted for power distribution, its protection function is ().
A. power failure protection
B. Short-circuit protection of pilot control loop
C. Open-phase protection
D. short circuit, overload and leakage protection
Answer d
5. The cross section of the main core wire is 35mm.
A. 138A
B. 1 13A
C. 173A
D.85A
Answer a
6, mine cavern () it is forbidden to use low-voltage electrical equipment.
A. oil-immersed type
B. Intrinsically safe type
C. Sand-filling mold
D. pouring sealing type
Answer a
7, underground, bottom and its vicinity, mechanical and electrical cavern and work cavern, sidewalk and other major workplaces must have () lighting.
A. temporary
B. appropriate
C. sufficient
Answer c
8, involving safety in production of coal mine products, must go through safety inspection and obtain coal mine products ().
A. Explosion-proof signs
B. Well entry certificate
C. Safety signs
Answer c
9, electric locomotive overhead line hanging height, from the rail surface to the bottom, from the bottom to the parking lot is not less than ().
A. 1.0m
B.2 million
About 2.2 million
3.0m in diameter
Answer c
10, the intact standard requirements of small winch are: the brake band has no cracks, and the residual thickness of wear is not less than ().
1.2 mm
3 mm
C.4mm？
Answer b
1 1, the action resistance of the leakage relay is determined according to the insulation resistance ().
A. Minimum network permissions
B. Network measurement
C. cable in that network
Answer a
12, if a mine electromagnetic starter works, JDB protection trips, and it can't be started again after tripping. Through analysis, it can be judged that it is () fault.
A. short circuit
B. Overload or open phase
C. Electric leakage
Answer a
13, when installing the comprehensive protection device of coal electric drill, it should be reliably grounded, and the auxiliary grounding should be outside the main grounding ().
$3 million
4 million pounds
About 5 million
Answer c
14. When installing a comprehensive protection device for a coal electric drill, the insulation of the device should be measured 1 time before wiring, and the insulation resistance of the high and low voltage sides should be measured with a 500V megger, and the insulation resistance should be no less than ().
A.5MΩ
b . 10mω
c . 15mω
Answer a
15, the difference between the inner diameter of the sealing ring and the outer diameter of the cable should be less than ().
2.5 mm
B. 2.0 mm
C. 1.0 mm
Answer c
16. When the rubber cable is connected with various pins, the socket must be connected to the side of ().
A. load
B. Power supply
C. arbitrary
Answer b
17. Warning signs with the word () should be hung at the entrance or door of each transformer (distribution) station.
A. non-staff members are not allowed to enter
B. No admittance for idle people
C. Electrical hazards
Answer a
18, mine high voltage power grid, measures must be taken to limit the single-phase grounding capacitor current not to exceed ().
A. 10A
B.20A
C.30A
Answer b
19, when the cable is connected, the width of the sealing ring should be not less than or equal to 0.7 times of the cable (), but it must be greater than10mm.
A. outside diameter of core wire
B. outside diameter
C. Inner diameter of wire inlet
Answer b
20, check the cable insulation state, for the cable below 1000V with 500V or () megohmmeter measurement.
A. 1000 volts
B.2500V volts
C./kloc-above 0/000 volts
Answer a
2 1. The withstand voltage test of the rubber cable () hot-patched or cold-patched on the ground shall be twice the rated voltage plus 1kV, and it shall be deemed as qualified if it does not break down for 5 minutes.
A. dry ...
B. Flooding
C. oil immersion
Answer b
22, ordinary portable electric measuring instrument, must be used where the gas concentration is lower than (), and real-time monitoring of gas concentration in the use environment.
A: 1.0%
B. 1.2%
C. 1.5%
Answer a
23, a mine power supply system () failure, because its bus is connected by multiple connectors, so check the fault, generally from the middle apart 1 connector, use 2500V megohmmeter to check the fault range.
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124. 166.98.* Second floor
A. excessive current
B. grounding
C. Electric leakage
Answer c
24, flame-proof shell crack, welding, length more than () serious deformation, at the same time, the pit depth more than 5mm for the loss of explosion.
A. 30 mm
40 mm
50 mm
Answer c
25, flip type or plug type flame-proof joint width is less than (), the gap is greater than 0.5mm for loss of explosion.
A.15mm
20 mm
About 25 mm
Answer c
26, underground flameproof electrical equipment (such as asynchronous motor) insulation resistance to ground and interphase insulation resistance should be not less than ().
A.3MΩ
B.4MΩ
C.5MΩ
Answer c
27, coal winning machine must be installed inside and outside the spray device, when cutting coal must spray dust, spray pressure shall not be less than 2MPa, spray pressure shall not be less than? ()。
A. 1.5 MPa
B. 2.0 MPa
C. 2.5 MPa
Answer a
28, scraper conveyor and belt conveyor lap transportation, lap length is not less than 500mm, the nose and tail height difference is not more than ().
A. 300 mm
400 mm
About 500mm
Answer c
29, underground distribution network to check the breaking capacity of switchgear using ().
A. Maximum three-phase short-circuit current
B. Minimum two-phase short-circuit current?
C. long-term load current
Answer a
30, the reliable action coefficient of underground distribution network calibration protection device adopts ().
A. Maximum three-phase short-circuit current
B. Minimum two-phase short-circuit current
C. long-term load current
Answer b
3 1, underground low-voltage feeder, must be equipped with ().
A. selective single-phase grounding protection device
B. leakage detection protection device or selective leakage protection device
C. Leak locking
Answer b
32, when using a coal plough, working face Angle above (), and supporting the scraper conveyor must be installed anti-skid, anchoring device.
A.20
B 15
C. 12
Answer c
33, directly to the underground power supply of high voltage feeder, it is forbidden to furnish ().
A. Leakage protection
B. Automatic reclosing
C. lightning arrester
Answer b
34, coal mine underground 660V power grid leakage protection device action resistance is ().
a . 1 1kω
b . 15kω
C.3.5kΩ
D.6Kω
Answer a
35, mine explosion-proof electrical equipment including flameproof type ().
A.8
B.6
C. 10
D. 12
Answer c
36, intrinsically safe explosion-proof electrical equipment level ().
Alcoholics Anonymous Association and ID Card
Id card and ID card
C.ia and ib
D.ib and ic
Answer c
37, in the total return air lane and special return air lane () laying cables.
A. Should not
Yes
C. with the approval of the mine manager, you can
Answer a
38, in the coal mine () use miner's lamp personnel apart, knock, impact miner's lamp.
A. Allow
B.this is forbidden.
C. Allow access to the alley
Answer b
39, gas emission area, high gas mine and coal and gas outburst mine, () tunneling faces should adopt three kinds of special power supply, namely special transformer, special switch and special line.
A. roadheader
B. Coal electric drill
C. local ventilator
D. scraper conveyor
Answer c
40, underground cable () adopts aluminum-clad cable.
A. Must
B.this is forbidden.
C. no
Answer b
4 1, the location of the local ventilator, must realize () atresia.
A. Wind power
B. Gas and electricity
C. biogas power generation
Answer a
42, mining area electrical equipment using () power supply, special safety measures must be formulated.
A.1140v
660 volts
About 3300 volts
Answer c
43, overload refers to the actual current value of electrical equipment exceeds the allowable value of electrical equipment (), and exceeds the allowable overload time.
A. Starting current
B. rated current
C. Maximum current
Answer b
44, regularly check the insulation of cables and electrical equipment, and do () test in accordance with the provisions.
A. stage
B. On site
C. Preventive measures
Answer c
45, underground distribution voltage at all levels and rated voltage level of all kinds of electrical equipment, high voltage does not exceed ().
A.6000V volts
B. 10000 volts
C. 100000 volts
Answer b
46, underground distribution voltage at all levels and the rated voltage level of various electrical equipment, low voltage does not exceed ().
660 volts
B. 1 140 volts
About 3300 volts
Answer b
47, underground cable length should conform to the actual needs, if you need to extend, the joint must conform to the requirements of cable connection, put an end to ().
A. sheep tail, split joint and chicken feet
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124. 166.98.* Third floor
B. junction box connection?
C. Repair the connection
Answer a
48, the rated voltage of the remote control line, not more than ().
A. 127V
36V
380 volts
Answer b
49, the mine power cord road it is forbidden to furnish ().
A. Three-phase watt-hour meter
B. Load quantifiers
C. Undervoltage protection
Answer b
50, rubber cable grounding core, in addition to monitoring the grounding circuit, () and he used.
A. number
Yes
C. This can be done under special circumstances.
Answer a
5 1, the electrical gap refers to the () space distance between two bare conductors.
A. average
B. the shortest
C. the longest
Answer b
52, motor open phase refers to the three-phase AC motor () winding disconnect.
A. 1 phase
B.2 stage
C.3 stage
Answer a
53, () direct connection between different types of cables.
A. Yes
B. Must
C.this is forbidden
Answer c
54, high voltage cable leakage and withstand voltage test, every year ().
A. 1 time
B.2 times
About 3 times
Answer a
55, from the point of electric shock danger, () above is dangerous voltage.
A. 12V
24V
About 36V
Answer c
56, underground stringing electric locomotive commonly used is the voltage level of 250V or 550V () power supply.
A. Communication
B. direct current
C. high frequency
Answer b
57, overcurrent refers to the rated current through electrical equipment and cables ().
A. less than
B. equal to
C. Exceed
Answer c
58, low voltage distribution points or places equipped with more than () electrical equipment, local grounding should be installed.
A.2 sets
B.3 sets
C.4 sets
Answer b
59, explosion-proof electrical equipment explosion-proof mark for ().
A. ex-husband; Ex-wife; Ex-boyfriend; Ex-girlfriend
B. Massachusetts
C.ⅱA
Answer a
60, the power supply voltage is lower than 1 140V plug-in device, if the lack of linkage to prevent sudden pull out, can be set to ().
A. intact
B. qualified
C. Explosion losses
Answer c
6 1, plug-ins with power supply voltage above 1 140V can be classified as misfire if they are electrically interlocked.
A. Yes
B.no
C. both positive and negative
Answer b
62, () and above the motor, should use vacuum electromagnetic starter control.
A. 30 kilowatts
40kW
About 50 kilowatts
Answer b
63, except in the air intake inclined shaft, bottom and its vicinity, between the central substation and mining substation, other locations must use ().
A. aluminum core cable
B. Copper core cable
C. Special cables
Answer b
64, mine substation main transformer should have at least ().
A.2 sets
B.3 sets
C.4 sets
Answer a
65, the use of drum shearer, working face Angle above (), there must be a reliable anti-skid device.
A. 15
b20
C.25
Answer a
66, coal face scraper conveyor must be installed to stop and start the signal device, the spacing of signal points shall not exceed ().
About 20 meters
B. 18m
C. 15m
Answer c
67, scraper conveyor head and tail must be laid firmly ().
A. top beam
B. steel prop-pulling
C. Anchor column
Answer c
68, underground central substation (substation) at all levels, the main drainage pump room and down the mountain mining area drainage pump room power supply circuit shall not be less than two circuits. Its power supply line should come from its own transformer and bus section, and any load should be tapped on the line ().
A. Yes
B. after approval, you can
C. In addition to the lighting load, it should not be
D. Should not
Answer d
69, mobile and handheld electrical equipment should use ().
A rubber-sheathed flexible cable conforming to MT8 18 standard.
B.MVV armored cable
C.MVV plastic cable
D. Special rubber sheathed cable
Answer d
70, the determination of the grounding resistance of the mine power supply system grounding network, every () determination 1 times.
A. Nervous (short for jittery)
B months
C. Half a year
D. year
Answer a
7 1, grounding resistance of newly installed electrical equipment, () to be measured.
A. Every month
B. Every day
C. Every quarter
D. Before putting into operation
Answer d
72, underground explosion-proof communication, signal and control device, should be preferred ().
A. increased safety type
B. flameproof type
C. special type
D. Intrinsically safe type
Answer d
73, explosion-proof electrical equipment in use explosion-proof performance inspection, inspection cycle is () 1 times.
A. every week
B. Every year
C. quarterly
D. Every month
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124.166.98. * 4th floor
Answer d
74, the rated voltage of electrical equipment is 660V, electrical clearance should be greater than ().
1.4 mm
B.6mm mm
C.10mm
8 mm in diameter
Answer c
75, mobile and handheld electrical equipment should use () rubber cable.
A. Mining
B. Split-phase shielding
C. exclusive use
D. soft
Answer c
76, the physical and chemical properties of insulating oil used in electrical equipment test and electrical withstand voltage test, () should be 1 test.
A. Every year
B. quarterly
C. Every 3 years
D. every six months
Answer a
77, coal, gangue, material chute () laying cables.
A.this is forbidden.
Yes
C. With safety measures, you can
Answer a
78, the operation of underground electrical equipment should comply with the regulations, hand-held electrical equipment operating handle and work must contact part () insulation is good.
A. it is better to have
B.there must be
C. unnecessary
Answer b
79, due to maintenance, power failure or other reasons to stop the main fan operation, must make ().
A. Power outage measures
B. Inspection scheme
C. Windbreak measures
Answer c
80, when choosing underground electrical equipment, must conform to the ().
A. explosion-proof requirements
B. Protection requirements
C. requirements of coal mine safety regulations
Answer c
8 1. When the gas concentration in the airflow near the installation site of the motor or switch reaches (), it is necessary to stop working, cut off the power supply, evacuate people and deal with it.
A. 10m， 1.5%
20m, 1.5%
About 20m, 1.0%
Answer b
82, safe voltage depends on the size of the human body resistance and ().
A. Safe current
B. Operating voltage
C. Insulation resistance of power grid
Answer a
83, the starting sequence of belt conveyor is ().
A. inching, signaling, observing and starting.
B. signal, observe, jog and start.
C. signal, observe and start the machine.
Answer b
84, underground electrical equipment voltage above 36V must have ().
A. protective grounding
B. Grounding electrode
C. grounding grid
Answer a
85, cable must be suspended, in the horizontal roadway, cable should be made by ().
A. steel wire suspension
B. Copper wire suspension
C. Hook suspension
D. place clips, fixtures, etc.
Answer c
86, cable must be suspended, in the vertical shaft, cable should be made by ().
A. steel wire suspension
B. Copper wire suspension
C. Hook suspension
D. place clips, fixtures, etc.
Answer d
87, underground high-voltage motor, power transformer and other high-voltage control equipment, should have ().
A. short circuit, overload, grounding and undervoltage release protection
B. short circuit, overload and leakage protection devices
C. Short circuit, overload, single-phase disconnection, leakage locking protection device and remote control device
Answer a
88, underground by mining substation branch, should be installed ().
A. short circuit, overload, grounding and undervoltage release protection
B. short circuit, overload and leakage protection devices
C. Short circuit, overload, single-phase disconnection, leakage locking protection device and remote control device
Answer b
89, low-voltage motor control equipment, should have ().
A. short circuit, overload, grounding and undervoltage release protection
B. short circuit, overload and leakage protection devices
C. Short circuit, overload, single-phase disconnection, leakage locking protection device and remote control device
Answer c
90, reprint machine must signal before starting, to ensure that no one work on or near the reprint machine, inching start () times first, and then officially started.
A.2 ~ 3
B. 1~2
C.3~4
Answer a
9 1. When there are two or more voltages in the underground low-voltage distribution system at the same time, it should be clearly marked on the low-voltage electrical equipment ().
A. rated voltage
B. rated power
C. rated current
Answer a
92, wind power atresia is fan stalling, () the power supply is cut off at the same time.
A. Fan
B. Driving surface power
C. all
Answer b
93, gas electrical atresia is when the gas overrun, cut off the power supply and atresia ().
A. Fan
B. Driving surface power
C. all
Answer b
94, () refers to the insulation monitoring of the power grid before the switch is closed. When the insulation value of the power grid to the ground is lower than the locking value, the switch cannot be closed, which plays a locking role.
A. wind power generation locking
B. Leak locking
C. gas electric locking
Answer b
95, protective grounding can reduce the electric shock voltage to a safe value, reduce personal electric shock current (), and minimize the danger.
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124. 166.98.* fifth floor
A. Time
B. size
C. Scope
Answer b
96, if a mine electromagnetic starter work, JDB protection tripping, and can restart after a certain delay after tripping, the analysis can be judged as () fault.
A. short circuit
B. Overload or open phase
C. Electric leakage
Answer b
97, if a mine electromagnetic starter stops working, JDB protection action can't start, through the analysis can be judged to be () fault.
A. short circuit
B. too much
C. Electric leakage
Answer c
98, choose the rated current of AC contactor, is determined by ().
A. motor load
B. Starting current
C. Rated current of motor
Answer c
99, working face because of the gas overrun and cut off the power supply of electrical equipment, must be below the gas concentration dropped to (), to reply to start the equipment.
A: 0.5%
1.0%
C. 1.5%
Answer b
100, the contact (copper contact) of the low-voltage flameproof switch is worn to the original thickness (), and the overtravel pressure is lower than the specified value, so the contact should be replaced.
A. 1/2
B. 1/3
C. 1/4
Answer b
10 1. Check the insulation of the high-voltage cable connector at least () times.
A. every day; Tiantiandi
B. every week
C. Monthly
Answer b
102, and the application area of the () grounding electrode set in the ditch is not less than 0.6m
A. auxiliary
B. Lord
C. local
Answer c
103, set in other wet places nearby. The local grounding electrode can be made of steel pipe with a length not less than () and a diameter not less than 35mm.
A. 1.0m
B. 1.5m
About 2.0 meters
Answer b
104, the cross section of the grounding bus connected to the main grounding electrode shall not be less than 50 mm
A. Low carbon steel wire
B. aluminum wire
C. copper wire
Answer c
105, the connection between the shell of electrical equipment and the grounding bus or local grounding electrode, and the connection between the armor at both ends of the cable connection device and the lead skin should adopt a section of not less than 25mm.
A. lead wire
B. copper wire
C. flat steel
Answer b
106, () The transformer or generator directly grounded by the ground neutral point directly supplies power to the underground.
A.this is forbidden.
Yes
C. If necessary, you can
Answer a
107, the fuse () is connected in the protected circuit.
A. and
B. line
C. serial or parallel
Answer b
108, the sealing ring in explosion-proof electrical appliances is made of rubber with Shore hardness of () and aged according to regulations.
45 ~ 60 degrees
B.35 ~ 45 degrees
C.55 ~ 65 degrees
Answer a
109, underground mechanical and electrical equipment cavern, all kinds of () should set aside a distance of more than 0.8m.
A. lighting equipment
B. Equipment and walls
C. Device interaction
Answer c
1 10, the flattening amount of the nozzle of the pressure plate after pressing the cable () 10% of the cable diameter.
A. Not exceeding
B. It should exceed
C. It should be equal to
Answer a
1 1 1. Before moving and overhauling electrical equipment underground, the power supply must be cut off and the gas must be checked. Only when the gas concentration in the roadway airflow is lower than () can electricity be checked.
A: 0.5%
1.0%
C. 1.5%
Answer b
1 12, the hanging height of overhead conductor of underground electric locomotive from the rail surface shall not be less than () at the intersection of pedestrian roadway, parking lot and sidewalk with transportation roadway.
A.1.8m
B. 1.9 m
About 2.0 meters
Answer c
1 13, the three major protections of coal mine power supply system refer to ().
A. overcurrent, leakage and grounding protection
B. overload, leakage and grounding protection
C. short circuit, leakage and grounding protection
Answer a
1 14, the leakage relay must be inspected and maintained in detail every () 1 time.
A. month
B.day
C. Zhou
Answer a
1 15, 1 The leakage relay must be tripped every ().
A. day
week
C. month
Answer a
1 16, the leakage relay should be maintained every ().
A. Zhou
B months
C. Year
Answer c
1 17, and the sensitivity coefficient of electromagnetic overcurrent relay shall be () 1.5.
A. less than or equal to
B. greater than or equal to
C. Less than
Answer b
1 18, the grounding resistance of any protective grounding point on the grounding network shall not exceed ().
a . 1ω
B2ω
C3ω
Answer b
1 19. The resistance value of cable core and grounding connection wire for grounding protection between each mobile and handheld electrical equipment and local grounding electrode shall not exceed? ()。
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124. 166.98.* 6th floor
a . 1.5ω
b . 1.0ω
c . 2.0ω
Answer b
120, the rated voltage of lighting, signal, telephone and handheld electrical equipment shall not exceed ().