TRANSFORMERS AND PCB'S Flashcards
WHAT IS THE IDENTIFIER OF THE PRIMARY AND SECONDARY WINDINGS?
THE PRIMARY WINDINGS RECEIVES THE LINE INPUT
THE SECONDARY IS CONNECTED TO THE LOAD
WHAT IS A TRANSFORMER?
A MAGNETICALLY OPERATED MACHINE THAT CHANGES VOLTAGE, CURRENT, AND IMPEDANCE.
WHAT CANT A TRANSFORMER CHANGE?
FREQUENCY
WHAT IS THE IDENTIFIER OF AN AUTOTRANSFORMER?
AN AUTOTRANSFORMER ONLY HAS ONE SET OF WINDINGS FOR THE PRIMARY AND SECONDARY.
WHAT IS SELF INDUCTION?
WHEN A COIL INDUCES A VOLTAGE INTO ITSELF
WHAT IS AN ISOLATION TRANSFORMER?
THE PRIMARY AND SECONDARY WINDINGS ARE PHYSICALLY AND ELECTRONICALLY ISOLATED FROM EACH OTHER.
HOW ARE SOME AND ONLY ISOLATION TRANSFORMERS BUILT?
WITH A 1:1 TURN RATIO FOR ISOLATION ONLY
ALL TRANSFORMERS ARE PROPORTIONAL TO WHAT?
THERE TURNS RATIO.
WHAT IS MUTUAL INDUCTANCE?
THE ABILITY TO INDUCE VOLTAGE FROM ONE COIL TO ANOTHER.
NAME THE 3 FUNCTIONS OF THE OIL IN A TRANSFORMER.
COOLING, INSULATING, AND PREVENT MOISTURE.
EXPLAIN: I LINE= I PHASE
IN A WYE CONNECTION THE LINE AND PHASE CURRENT ARE THE SAME.
EXPLAIN: E LINE = E PHASE X 1.732
IN A WYE CONNECTION THE LINE VOLTAGE IS HIGHER THAN THE PHASE VOLTAGE BY A FACTOR OF THE SQUARE ROOT OF 3
EXPLAIN: I LINE = I PHASE X1.732
IN A DELTA CONNECTION THE LINE CURRENT IS HIGHER THAN THE PHASE CURRENT BY A FACTOR OF THE SQUARE ROOT OF 3.
EXPLAIN: E LINE = E PHASE
IN A DELTA CONNECTION THE LINE AND PHASE VOLTAGE ARE THE SAME.
WHAT ARE HARMONICS AND WHEN DO THEY OCCUR?
VOLTAGES OR CURRENTS THAT OPERATE AT A FREQUENCY THAT IS A MULTIPLE OF THE FUNDAMENTAL POWER FREQUENCY EX. 120,180,240,ETC.
NAME 4 TYPES OF INTERRUPTING MEDIUMS?
OIL, VACUUM, SF6, AND DRY AIRBLAST
WHAT ARE BREAKERS FOR?
PROTECTION
3 WAYS BREAKERS CAN BE TRIPPED?
ELECTRICALLY, MECHANICALLY, AND PNEUMATICALLY
DISADVANTAGE TO SF6?
THE BI-PRODUCTS ARE VERY CORROSIVE.
MOST COMMON GAS FOR BREAKER?
SULFUR HEXAFLOURIDE
WHY IS SPEED DESIRABLE FOR CIRCUIT BREAKERS?
EXTINGUISHING THE ARC, REDUCE PITTING AND BURNING OF THE CONTACTS.
CIRCUIT BREAKER RATINGS?
VOLTAGE CLASS, CONTINUOUS CURRENT, INTERRUPTING CAPACITY
SIMPLEST CIRCUIT BREAKER
KNIFE SWITCH BREAKER
WHY DOES SF6 NEED TO BE HEATED?
BECAUSE THE GAS LIQUIFIES
