Non-class 120vac Instrument Power(NN)

Question 1

Describe the main purpose of the Non-class 120vac Instrument Power

Answer 1

•It supplies single phase, regulated and filtered 120vac to Non-class instrument and control subsystems.

Question 2

What does a subsystem consist of?

Answer 2

•Normal supply ‘Voltage Regulator’
•Alternate supply ‘Voltage Regulator’
• A static transfer switch between normal and alternate power sources
• A manual bypass switch
•A distribution panel
-NNN-D11
-NNN-D12
-NNN-D15
-NNN-D16

Question 3

What different types of sources can the Distribution panels receive?

Answer 3

•Non-class 480v MCC

•Non-class 480v MCC (SIAS LOAD shed MCC’s M-19&M20)

•Class 480vac MCC (PHA&B)