Chapter 1 Flashcards
Self-Contained Meters
What is a self-contained meter?
Has the capability to have all load current for the service flowing through it at the rated service voltage
What are the types of self-contained meters?
- Single-Phase
- Polyphase
- Electromechanical
- Solid State
- Demand
What are self-contained meters limited to?
Secondary metering which is 600V or 400A
What makes up a Meter Stator?
One current coil and one potential coils working together to turn one disk
A one-element meter is all that is required to measure what?
The energy in a two-wire 120V service.
What is the wire size of the current coil of a meter element?
Big enough to carry the rated load of the meter and consists of a small number of turns.
In a self-contained meter, what does the current coil carry?
The entire load current.
What is the voltage coil of a meter element needed for?
To combine with the current coil to induce a magnetic field onto the meter disk causing it to rotate
What is the voltage coil made up of?
Fine wire
What are typical voltage ratings?
120, 240, 480, 600
What is a solid state meter?
Meter with no moving parts
What are the two types of solid state meters?
Electronic or Smart
What is a solid state meter made up of?
Voltage sensor and Current sensor
What are voltage sensors?
Typically small resistive voltage dividers
What are current sensors?
Small CTs
