Connections
The three-phase connection in which one end of each of the windings are connected together is called the ____ connection.
wye
An open delta connection is made using ____ single-phase transformers.
two
A delta-connected three-phase alternator is driving a wye-connected resistive load. The alternator output voltage is 480 V. The load resistors are 12 ohms each. What is the phase current in the alternator?
13.33 A
A transformer tape wound core is also called a ____ core.
toroid
The amount of current that flows into a transformer primary when voltage is first applied is called ____ current.
inrush
Line current and phase current are the same in the ____ configuration.
wye
In three-phase transformer connections, the primary leads are labeled with the letter ____ and the secondary leads are labeled with the letter ____.
H, X
A delta-delta transformer has a primary voltage of 7200 V and a secondary voltage of 360 V. What is the turns ratio?
20:1
A transformer tape wound core is assembled by ____.
winding a long continuous tape of metal into a spiral
In calculating power in a three-phase circuit, the product of phase voltage and phase current and power factor are multiplied by ____.
3
A delta-wye transformer has its ____ connected as a delta and its ____ connected as a wye.
primary, secondary
The magnetically operated device that can change values of voltage, current, and impedance without changing frequency is the ____.
transformer
A wye-delta transformer has a primary voltage of 7200 V and a secondary voltage of 360 V. What is the turns ratio?
11.55:1
The transformer that converts a high (7200 V) voltage from the power company down to 120/240 V for homes and businesses is called a ____ transformer.
distribution
In an open delta with single-phase loads, the high leg must be identified by ____.
either using orange wire or tagging
In a three-phase connection, the current that flows in an externally connected voltage conductor is the ____ current.
line
A simplified schematic diagram of three-phase transformer connections is called a ____ diagram.
one-line
A delta connected set of windings has a phase voltage of 100 V. The line voltage is ____.
100 V
A transformer supplying a house with 120/240 V has a secondary which is center tapped. The conductor connected to the center is called the ____ conductor.
neutral
For installations that will have both three-phase and single phase loads on a three-phase transformer, the utility company often provides a(n) ____ three-phase transformer.
open delta with one transformer center tapped
Another name for the three-phase wye connection is the ____ connection.
star
A transformer in which the secondary voltage is more than the primary voltage is called a ____ transformer.
step-up
AN open delta transformer is assembled from two 50 kVA transformers. The output power of the open delta is ____.
86.6 kVA
A transformer that does not isolate the out from the input is called a(n) ____ transformer.
auto
Dielectric oil performs what function(s)...
acts as an insulator, provides cooling, and prevents moisture formation