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WorksheetsThree-Phase Transformers and Configurations
Total questions: 12
Worksheet time: 6mins
What is the most common method utilized by utility companies for three-phase services?
Single-phase transformer
Interconnecting three single-phase transformers
Two-phase transformer
None of the above.
Fill in the blank: A three-phase transformer unit is basically three single-phase transformers inside a ______.
Single tank
Double tank
Triple tank
Quadruple tank
Fill in the blank: The kVA rating of the transformer is clearly printed on the ______.
Front
Back
Side
Top
What is the responsibility of the lineworker according to the text?
Designing transformers
Confirming transformer nameplate information
Manufacturing transformers
Selling transformers
What is the purpose of the transformer nameplate according to the text?
To decorate the transformer
To provide installation instructions
To indicate transformer sizes in kVA
To show the manufacturing date.
In a three-phase transformer, which coil is always positive?
H-1
H-2
X-1
X-3
Fill in the blank: Transformers with a primary rating of 8,660 volts and below will be rated ______ polarity.
Additive
Subtractive
What is the allowable range of impedance difference between transformers according to industry standards?
5%
10%
7.5%
20%
Which type of transformer connection always has a positive terminal connected to a negative terminal?
Delta
Wye
Zigzag
Star
Fill in the blank: A reversed polarity on one transformer of a three-phase bank will result in an extremely ______ current flow.
High
Low
Fill in the blank: The lowest impedance transformer will supply a greater share of the load and possibly end up being ______.
Overloaded
Underloaded
What should be done to ensure proper transformer selection?
Check polarity
Check impedance
Check voltage
All of the above.
