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K_{h}
 Watt hour constant
 The value of 1 revolution of the meter disk, Expressed in watt hours.

R_{r}
 Register Ratio
 The number of turns of the 1^{st} gear of the register to cause the 1^{st} (or right hand) dial pointer to complete 1 full revolution which = 10,000 watt hours or 10kwhrs.

R_{g}
 Gear Ratio
 The number of turns of the meter disk to cause the 1^{st} (or right hand) dial pointer to complete 1 full revolution = 10,000 watt hrs or 10kwhrs.

R_{s}
 Reduction at Shaft
 The ratio between the number of teeth on the 1^{st} gear of the register to the number of entries on the disk shaft.

K_{r}
 Register Constant or Multiplier
 Multiplier of the register, due to gearing.

TF
 Transformer Factor
 Multiplier of the register, due to CT’s and/or CT X PT ratios.

Test Amps
Amperage used with line voltage to set the speed of the disk in 1 hour’s time. (1000Rph 1phase) (500Rph Poly phase)

PKh
Watthour Constant x Transformer Factor

Demand
The average rate of consumption over a specific period of time

Calibrating Constant
The inverse of the number of current circuits in series under test.
(Establishes the Kh of individual elements)

Power
An electrical load expressed in watts or kilowatts without a relationship to time. E x I=Watts

Energy
An electrical load expressed in watts or kilowatts times the number of hours it’s used.
E x I x time factor = Kwhr

Stator (Meter Element)
The unit that provides the driving torque in a watthour meter. It includes the PotentialCoil, the CurrentCoil and the related framework to provide a magnetic flux or path

Blondel's Theorum
In a system of Nconductors, N1 metering elements properly connected, will measure power and/or energy consumed, provided that all potential coil(s) have a common connection in which no current circuit(s) are connected.

Test Amps Formula
 E x I x CC x TF
 1,000 Rph for single phase
 500 Rph for Polyphase

Register Ratio Formula
 10,000 x K_{r}
 TFxK_{h}xR_{s }

Watts Formula
 K_{h }x 3600 x revs
 Time in seconds





Power Formula
Volts x Amperes (or) E x I

Energy Formula
Volts x Amperes x Time (or) E x I x Time

Demand Formula
 E x I x CCx TF 1000
 where “I” is equal to the amperage
 on the meter under test

Draw and label a FM5, FM6, FM8 and FM9 socket and abase meter

Draw the following meter banks and the corresponding meters (abase and socket) for each bank:
 4W3phase wye
 3W3phase open delta
 4W3phase closed delta

Draw and connect a FM1 socket Preferred, Nonpreferred, and set on neutral

What is an Ohm?
The practical unit of electric resistance.

Define Percent Registration
The ratio of the actual registration of the meter to the value of the quantity measured in a given time, expressed as a percentage

What is capacitance?
The property of an electric circuit which allows storage of energy and exists whenever two conductors are in the close proximity but separated by an insulator or dielectric material

What is conductance?
The ability of a substance or body to pass an electric current

Define Detent
A device installed in a meter to prevent reverse rotation of the meter disk

What is a demand register?
A mechanism that indicates maximum demand and also registers energy used

What is a cycle?
One complete set of positive and negative values of an alternating current or voltage

Define Volt
The practical unit of electromotive force, or potential difference

Form Designation
The industry wide standard to describe the meter construction and wiring.

Transformer Factor Formula
 TF = 10,000 x Kr
 Kh x Rr x Rs
 (or)
CTRxPTR

What is the KW demand on an Itron Sentinal FM9 with 6000 internal pulses? Show work
3.6KW

How many internal pulses are on an Itron FM16 with a demand of 36KW? Show work
5000 pulses

Be able to calculate watts, TF and PK_{h } with values provided.

Prove Voltages on both Delta and Wye services using Trigonometry

Misapplication of a FM2 on a Wye bank. Draw and explain. Also what % the meter registers vs customer uses on phase to phase loads and phase to neutral loads.
Refer to Vector Class Powerpoint pg 89

Draw and explain a FM12 where the 5th terminal is not connected to ground.
Also what % the meter registers vs customer uses on phase to phase loads and phase to neutral loads.
Refer to Vector class powerpoint pg 14

