单选题If an electric motor driven air compressor fails to start, it may be due to a （）.Aleaking discharge valveBjammed suction valveCtripped overload relayDbroken discharge un-loader
单选题
If an electric motor driven air compressor fails to start, it may be due to a （）.
A
leaking discharge valve
B
jammed suction valve
C
tripped overload relay
D
broken discharge un-loader
参考解析
解析：
暂无解析
相关考题：
In an AC.synchronous motor electric propulsion plant,propeller speed is controlled by() A.prime mover speedB.number of energized main motor polesC.propulsion generator field strengthD.electric coupling field strength
_______is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.A.An air receiverB.An operating valveC.An automatic valveD.An air distributor
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.A.excessive pump speedB.excessive suction headC.worn wearing ringsD.gross pump misalignment
A hydraulic motor may be driven by______.A.an electric motorB.a diesel engineC.a compressorD.oil
这些舱盖通常是用电力或液压驱动的。（）A、These hatches are usually driven by electric or hydraulic power.B、These hatch covers are usually driven by electric or hydraulic power.C、These hatch covers are usually driven by electric.D、These hatch covers are usually driven by hydraulic power.
单选题On opposite ends of a single shaft of a turboblower are a gas driven （）and a air compressor, which are sealed each other.Acharge air receiverBscavenging air beltCturbineDair cooler
单选题这些舱盖通常是用电力或液压驱动的。（）AThese hatches are usually driven by electric or hydraulic power.BThese hatch covers are usually driven by electric or hydraulic power.CThese hatch covers are usually driven by electric.DThese hatch covers are usually driven by hydraulic power.
单选题The unloading system on an air compressor will （）.Aincrease compressor discharge pressure on demandBincrease compressor operating speed as necessaryCallow the motor to turn the compressor opposed only by frictionDreduce the compressor frictional load when starting
单选题操作完后，关掉电动机。（）AAfter operation, start the electric motor.BBefore operation, stop the electric motor.CBefore operation, start the electric motor.DAfter operation, stop the electric motor.
单选题If a diesel engine fails to start，one of the likely causes is （）Alow compression temperatureBlow ambient air pressureChigh lube oil pump pressureDhigh fuel oil booster pump pressure
单选题（）are supplied by main switchboard directly.ASuez Canal searchlight, air compressor and air conditioning compressorBAir compressor, boiler blower and refrigeration plantCBoiler blower, Suez Canal searchlight and refrigeration plantDSuez canal searchlight, air compressor and boiler blower
单选题If the electric motor driving an air compressor fails to start, the cause may be a （）.Aleaking unloaderBtripped circuit breakerCcontrol line leakDdefective pop valve
单选题“A centrifuge consists of an electric motor driving a vertical shaft on the top of which is mounted the bowl assembly”.According to this sentence, we can know that is mounted on the top of the vertical shaft（）Aa centrifugeBan electric motorCa bowl assemblyDa driving motor
单选题The drive motor will have a brake arranged to fail-safe, i√eit will （） the load if power fails or machine is stopped.AcastBputCholdDlet out
单选题If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably（）.Aexcessive pump speedBexcessive suction headCworn wearing ringsDgross pump misalignment
单选题（） is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.AAn air receiverBAn operating valveCAn automatic valveDAn air distributor
单选题The air compressor pumps air to the （）.Aexpansion tankBcombustion chamberCair receiverDevaporator
单选题The purpose of an air compressor unloading device is to （）Adrain water from the air receiverBdrain water from the cylindersCdelay the compression process until the motor is up to speedDcheck pump alignment
单选题Air compressor cylinder un-loaders enable the compressor to （）.Avary their speed according to temperature and loadBstart and come up to speed before air compression beginsCchange speed according to overload demandsDreduce compressed air charge density
单选题An air compressor can be unloaded at start-up by （）.Aholding the discharge valve openBrelieving the intercooler pressure to the atmosphereCusing an enlarged, permanently opened clearance expansion spaceDa pre-charged accumulator
单选题What type of electric motor is most commonly used on board ship?（）Anon-synchronous electric motorBsynchronous electric motorCfully enclosed electric motorDwatertight electric motor
单选题The hand steering is a method by which the motion of the rudder is controlled with （）.Aa motor-driven steering wheelBa pneumatic steering wheelCa hand-driven steering wheelDan electric steering wheel
单选题The air distributor is conventionally driven by（） and distributes into each cylinder by（） certain sequence.Acamshaft；fresh airBcamshaft；starting airCelectronic motor which is controlled by a computer；fresh airDelectronic motor which is controlled by a computer；starting air
单选题“This increase in charge air density is accomplished on most modern diesel engine types by use of exhaust gas turbo-charging, in which a turbine wheel driven by exhaust from the engine is rigidly coupled to a centrifugal type air compressor” According to this sentence, we can know that increases density（）, drives the compressor directly（）Aa modern diesel engine；a turbine wheelBa modem diesel engine；exhaust gasesCa compressor；an exhaust gas turbochargerDa compressor；a turbine wheel
单选题When a refrigeration compressor motor fails to start, the FIRST thing that should be checked for is a （）.Aloose expansion valve control bulbBlow differential setting on the H-PcutoutCblown fuse in the motor circuitDfaulty suction pressure regulator