calculations
general
#'s
definitions
general 2
100

delta windings have a phase current of 10A what is the line current

17.32A

100

transformer in which the secondary is larger then the primary

step-up

100

square root of 3

1.732

100

define autotransformer

transformers that have one winding for primary and secondary 

100

three phase connection voltage measured directly across the windings is 

Phase

200

delta windings have 480v line what is the phase volts

480

200

transformer in which the primary is larger then the secondary

step-down

200

2:1 turns ratio

P                       S

120                    ?

60

200

define laminated

Something made of thin sheets stacked

200

three phase the current that flows in an externally connected voltage conductor is

Line

300

P           S

240v       60v

I:              I:

W:               5 ohm

P                   S

240v               60v

I: 48*               I: 12*

P: 11,520*           5 ohms

300

define ground

earth

300

how do you find Ip

IL divided by 1.732
300

define primary winding

power input of a transformer

300

Line current and phase current are the same

Y

400

P                        S

240v                     120v

I:                           I:

va:480                         ohms:        R:

P                     S

240v                 120v

I: 2*                    I: 4*

va:480                ohms: 30*         R: 2:1*

400

Power input in a transformer is called 

the primary

400

how do volts relate to the primary and secondary

ones higher ones lower

400

define inrush current

the amount of current that is drawn when an inductive device is first connected

400

Line voltage and Phase voltage are the same

Delta

500

How do you determine voltage on a transformer

measure it

500

P                          S

V: 120                 V:

I:                         I: 10

va: 480                     ohm: 20        R:  1:1.667

P                          S

V: 120                     V: 200*

I: 4*                         I: 10

va 480                     ohm: 20

500

single phase

EP 7200               ES ?

AP ?                     AS 40

va 28800                w ?

ES 720

AP 4

W 28800

500

define current regulator

a transformer that supplies a constant amount of current

500

delta windings are 100v phase whats the line volts

100v