Principles and wiring diagrams
The formula we use for calculating Voltage/Current/Resistance.
What is Ohm's Law?
Hertz's.
What is frequency measured in?
Star and Delta.
What are the two most common connections for a 3 phase motor?
'One time' over current protection device.
What is a fuse?
Tug Test
When a ferrule is crimp or terminal tightened what must we always do?
The wire is blue and white.
What color wire is used for 0V?
60Hz.
What frequency is used in the US?
Balanced.
What should the resistance of each phase be on a good motor?
Bi-metallic strip, tripping coil and arc chute.
What internal components make-up an MCB?
Dead tester and proving unit.
What are the two pieces of electrical equipment used when we LOTO?
The third is 'load'.
If power supply and conductor is required to make a circuit, what is the third?
120 degrees.
How far, in degrees, is each phase to one another?
Insulation resistance tester.
Apart from a multimeter, which additional tester is used for 3 phase motor testing?
A1, A2, B1, 15, 16 and 18.
What terminals on an electronic timer?
Your name, your department and your supervisors cell phone number.
What is written on LOTO padlocks?
To the righthand side of the component.
Where do write the connections for a component on a electrical drawing?
2x3.14xfxL
What is the formula for calculating XL?
Slip
What is approx. 5% and has to be calculated when determining the correct motor speed?
Tripping type, trip current, number of poles and voltage.
What information is on an MCB?
Flash rated clothes, rated rubber gloves and leather covers, rated hard and face cover, rated shoes and balaclava.
When working on a live panel >50Volts, what PPE is required.
Arrows, page number and column.
How do we label wires that that are on another page?
208V 3 phase.
Apart from 480V, what lower 3 phase power is used in the US?
33 percent torque.
How much torque is produced when a motor is connected in star compared to delta?
B, C, D, K and Z.
What are the types of MCB?
Safe to work permit.
When more than one permit is required, what permit controls them all?