Ramsey Test
Solenoid valve fails to open, check what?
Normally closed (power to open)
ARC welding a 1/4 butt joint use
..
Low and high voltage motor wiring relating to delta and Y DRAWING NEEDED
..
Pulse width modulated signals produced?
..
What determines the regulation of a power supply?
..
With a refrigerator with no power on, the contactor is open, holding the coil has power..
..
common - bus variable frequency drives share?
..
what voltage is available on the secondary of a 480 / to a 480y?
..
Counter > Encoder > Machine speed (signal rate)
......
Size wire for 100-amp switch?
2-gauge
A cubic foot of steel weighs 500lbs how many pounds does a steels plate weigh dimension 3ft x 6ft x 3in
27,000 lbs
Maximum total degrees of bends in conduit?
360
Trending is the process of?
A trend is the general direction taken during a specified period of time..... Trend analysis is the process of looking at current trends in order to predict future ones and is considered a form of comparative analysis
Bearing ultrasound reading should be taken at what frequency? (high frequency threshold of a human)
B.) 20kHz
What 2 valves should be used to calibrate a pressure sensor?
Bleeding valve and block valce
Compressor running too hot, due to what? or do what?
Build up internal moisture and condensation
How many SCRs are needed minimum for a full wave reversing bridge rectifier?
D.) 12 6 forward and 6 reverse
Speed of induction motor is affected by 2 factors, answer was combination of 2
D.) Voltage and frequency
What determines the maximum safe speed when grinding?
D.) diameter of grinding wheel
On an air reciprocating pump, if you shut fluid discharge, the pump will?
D.) stall
First thing to do after you Meg a motor is?
Disconnect power or test megohmeter
Air cooled condensers generally have?
Fan, ambient air
What is the usual cause of overheating in high speed, grease-lubricated antifriction bearing
Faulty mounting practices
Hydraulic valves are typically adjusted by
Flow control valve and adjustment the control
Why choose grease over oil for a bearing?
Greases are better for leakage control and provide better seals against contaminants
A pilot flame detector can be what?
If flame is actually lit
In a closed loop servo, a tachometer generates?
Speed
What does an I/P transducer covert?
The I/P transducer converts an electronic signal, typically from a control system, to pneumatic signal used to control a valve
When air is compressed its temperature and....?
The pressure and temperature of the air increases
What is viscosity?
The resistance of a liquid to flow
This device does not require an analog input module on a PLC?
Thermocouple
Why are heavy oils used
To reduce the friction from heat and wear
What determines the selection of gear reducer size
Torque and speed
The insert, or spider, used in flexible jaw couplings is meant to
Transmit torque and accept misalignment
How to create an XOR logic with relays?
True table or logic gates
motor starter will not stay engaged
a bad holding coil
Air cooled condensers offer...
an air cooled condenser (ACC) is a direct dry cooling system where steam is condensed inside air-cooled finned tubes
Output is firing in the plc but no light is on
check bulb first
A transducer is a device that converts?
chemical or physical information into an electrical signal or the reverse
Air line filters and lubricators should be installed at
closer where it is going to be used
what does air do when its compressed
heat up
Exclusive or logic circuit?
is a logical operation that is true
Robotics "enable" a switch on the teach pendant allows what action
it allows robot movement when it is continuously activated
Measuring the inside of a pipe choose a device
micrometer
What color is a torch flame when gas only is on?
orange, yellow
pressure switch pictogram
pressure (half circle)
PLC output card, circuit has no opens or shorts but them is not turning on
replace output card
Which machine condition can be determined by using oil analysis?
Various types of wear and take corrective action before fails
motor with coil in parallel
shunt
tachometer on a servo motor reports back
speed
Stepper motor or synchronous motor define, older test
synchronous is an AC motor that the rotation of the shaft is synchronized with the frequency ofthe supply current
What is a Megger
the instrument used for measuring the resistance of the insulation
Rectifier converts
A.) AC to DC
What can you use to meet peak hydraulic system demands
A variable displacement pump
Variable frequency drives? And controllers
A variable frequency drive control the speed of AC motor by varying the frequency
Power supply question, fluctuating input of ______ affects output of ____?
A) Voltage B) Current
What voltage is available on the secondary of a 480V delta to 480V Wye?
A.) 480 Vpp / 230Vp-n
Inputs feeds an operational amplifier, what calculation is used to control Va
A.) Add
2 inputs for OP-Amp produces?
A.) addition
While using a saber saw to cut soft metal and blades fill with metal, what blade to switch to?
A.) finer tteths
transducer change
A.) reactance
Digital drive circuit with DC power that gives no positional feedback?
A.) servo motor
Acid form in lubricants from
A.) water vapor
Safe operating speed of an air motor is controlled by the
Air supply pressure
Air cooler condenser vs water cooled condenser
Air-cooled chillers have condensers that use ambient air to cool hot refrigerant.... water cooled condensers are typically tube in tube, tube in shell, or a plate type heat exchangers in which water from a cooling tower or other water source cools the refrigerant
Bending offset multiplier for 30 degree bends?
C.) 2
When tapping in cast iron
C.) Coarse
How detect metal objects
C.) inductance
Series circuits
C.) resistance are accumulative
Best way to identify control wires?
Color is usually the best way to identify electrical wiring. all wiring looks the same on the inside, but the outside coverings come in different colors.
Final element in a control loop is the?
Control valve
Control systems have what four basic components?
Controller, Amplifier, Actuator, and feedback
Main purpose of a rectifier is to?
Convert AC to DC
The speed of a piston is determined by
Crankshaft stoke and the engine RPM
Hydraulic reservoir suction lines can be raised for what
Create enough vacuum
Clutches on machinery provide for disengaging and may also
Interrupt the power supply
What is the pressure on a fluid
Measurement of force per unit area on an object in the fluid
How detect metal objects verify
Metal detectors work by generating an altering magnetic field that may interact with objects that are near this magnetic field
why do metal parts seize when there is a lack of lubrication
Metal to metal contact. (lube protects the bearing against corrosion)
Pressure in the hydraulic system can be controlled electrically by the use of
Metering the flow of fluid into or out
Regulation of a power supply refers to the ?
Output
Shutting fluid discharge of an air operated reciprocating pump will cause the pump to
Overstroke
Acids that form in lubricants affect performance are a result of
Oxygen from the air and high temperatures
How to put a bearing onto a shaft
Press fit
How to control pressure in a hydraulic system
Pressure control is achieved in hydraulic systems by metering the flow of a fluid into or out of a constrained volume
How can too much wear in gears be reduced
Proper meshed
Centrifugal pumps, cavitation can result in?
Pump performance deterioration, mechanical damage, noise and vibration
How to eliminate parallax error?
Read measurements at eye level
Regenerative solid state drive prevents
Regenerative drives take electrical energy generated by a motor and feed it back to the AC power source or to a common bus
Tool used to measure threads?
Screw gauge- thread gauge- pitch gauge
Excess oil on a cylinder rod because?
Seal Failure
Why are timing belts made with teeth
Doesn't slip
What causes lubrication oil to get milky
Mixing incompatible oils, contamination
For a full wave SCR3 phase delta, what is the minimum of SCRs?
B.) 6
Transformers one side A matched to A other side to ground (all transformers one side to neutral=Y) (2 of 3 transformers to neutral = delta)
B.) Y-Delta
How to reduce gear wear
B.) selecting the right pitch
Bearing oil breakdowns cause
B.) temperature
Parallel circuits
B.) voltage remain constant