Home > Preview
The flashcards below were created by user
electric
on FreezingBlue Flashcards.

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.

PKh
Watthour Constant x Transformer Factor

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

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

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.

List 3 rules of a right triangle
 Must contain a 90 degree angle
 All 3 angles must = 180 degrees
 Hypotenuse is always the longest side, always C
 Reference angle establishes the adjacent

COLD SEQUENCE METERING
Cordova's definition
BB Definition
 A 10,000 amp current limiting fuse disconnect ahead of the meter, located on the same wall as th meter within 2 feet of the meter.
 (Cordova's definition)
 The utilization of a fault current limiting disconnect device between the electric meter and the supply source.

HOT SEQUENCE METERING
The electric meter is connected directly to the service conductors without the use of a faultcurrent limiting disconnect or meter safetyswitch device between the electric meter and the supply source.

HIGHLEG
(Wild or Power leg)
 The phase having the higher phase voltage to ground on a 4wire deltaconnected service, where the midpoint of one phase winding is grounded.

SERVICE MAST
The service mast is the conduit containing the serviceentrance conductors where the point of attachment and the connection between the service drop and the serviceentrance conductors is located above the roofline. The conduit extends to a point, and the weather head is located, above the roof eave. The conduit passes through the eave of the building or extends past the roofline without passing through the eave. The means of attachment is attached to the service mast.

Are hardhats required outside of the truck?
No

When are class 2 rubber gloves required?
For cutting service drops during fire.

Are hard hats required every time you're outside of your truck?
no

DATA PULSES
Output pulses (KYZ) generated by the electric meter for use by the Customer.

SERVICE RISER
The service riser is the conduit containing the serviceentrance conductors where the point of attachment and the connection between the service drop and the serviceentrance conductors is located on a pole or below the roofline of the building being served. The conduit extends to a point, and the weather head is located, below the roof eave. The means of attachment is secured to the pole or building and is not attached to the service riser.

POINT OF ATTACHMENT
The point at which the servicedrop conductors are attached to a building or other structure.

CURRENT TRANSFORMER (CT)
An instrument transformer designed for the measurement or control of current.

EMT
Electric Metallic Tubing

GRC
Galvanized Rigid Conduit

IMC
Intermediate Metallic Conduit

ISOLATED TRANSFORMER BANK
A transformer bank which provides electrical service to a single customer.

NEC®
NATIONAL ELECTRICAL CODE
A publication of the National Fire Protection Association, Inc.

NESC®
NATIONAL ELECTRICAL SAFETY CODE
A publication of the Institute of Electrical and Electronic Engineers, Inc. as adopted by ANSI.


RACEWAY (gutter)
Any channel for holding bus bars, cables, or wires, which is designed for this purpose.

RESIDENTIAL METERING
Metering of services used for the exclusive use of the individual customer for domestic purposes.

SECONDARY CONDUCTORS
That part of the Company's distribution system, which connects the secondaries of the Company’s distribution transformers to the service drop or service lateral.

AUTHORIZED CLOSED LOOP
Authorized use of electric service that is temporarily not being metered.

When electric meter employees are working on Company premises other than electric meter shops, they shall conform to the safety rules of other departments?
True or False
 True
 Section 330.08 of safety manual

Pythagorean’s Theorem
(c2 = a2 + b2) or (b2 = c2  a2)


Watts Formula
 Kh x 3600 x revs
 Time in seconds


What is the vertical clearance from ground for servicedrops over other land traversed by vehicles?
16 feet

What is the max height of the point of attachment from final grade?
24 feet

How many days max can the company grant permission to close a loop
7 Calendar days

What size and material is required for service masts?
2” minimum GRC

Can conduit couplings be installed above the roofline
No

Can phone loops, cable TV conductors, grounding clamps, etc. be attached to the service mast.
No, only the Company’s power servicedrop conductors shall be attached to a service mast.

Can line and load conductors are permitted in the same raceway or conduit.
No

When are junction boxes, conduit fittings (e.g. LB’s), or other devices allowed?
Only with specific written approval from the Company’s local Electric Meter Department.

When can the Company authorize a closed loop on new electrical services.
Never on NEW services

What is the maximum length of #2 triplex service drop conductor to residential and commercial installations?
90 feet

What is Pythagorean's Theorem
(use to solve problem)
c2 = a2 + b2

Using the basic laws of Trigonometry solve/prove that the wild (high) leg is 208 volts from center tap neutral on a 120v/240v delta system.

Using the basic laws of Trigonometry solve/prove that the phasetophase wye voltage is 208 volts.

What is the maximum service span for a 1/O service?
80 feet

What is the maximum service voltage that can be attached directly to a building (except substations or transformer rooms)
2400 volts

How many feet must conduit extend beyond hardscape edge when service conductors are under hardscape?
2 feet

What is the minimum depth of UG service laterals?
24 inches

What are the length, diameter and material type of slip sleeves?
 18" long, Schedule 40PVC for 2 1/2" diameter
 18" long, Schedule 80PVC for 3" diameter

Can the bottom center knockout of a meter housing be used for line side UG conductors entering the housing?
No

What is the maximum length for an OH temp service drop?
70 feet

What is the maximum allowable number of risers on a building?
6 with only one set of conductors in each

What is the maximum number of cables in a standard singlephase pedestal with a 6position URD mole?
15

Should all electrical equipment be considered energized?
Yes, per safety manual.

Which safety rules apply when EM employees are working on company premises other than EM shops?
The Safety rules of other departments

When are Lineman's class 2 or higher rubber gloves required to be worn?
When cutting service drops at a fire or similar emergency.

Are hard hats required every time you're outside of your truck?
No

When can 2 employees work off a single ladder?
Never!

What is the maximum allowable metered load?
4,000 amps

Mast supports are required if the service attachment point exceeds what height?
48"

What is the maximum service span for a 4/O service drop?
70 feet

Service conductors must be in conduit when under hardscape. How many inches must conduit extend past the hardscape edge.
24

Uguard risers shall be grouped together and shall not occupy more than what percent of the pole?
40%

When shall electrical equipment be considered energized?
Always!

What are the minimum dimensions of a 200amp meter housing?
19" tall by 13" wide

Where and how must apartment numbers be marked?
By permanent durable means at the meter socket, corresponding breaker, tenant entrance.

Can a stamped brass address tag be on any location of the meter housing?
 No. Must be on a nonremovable portion.
 What is the max distance the point of attachment shall be located from the weatherhead?
 24"

What is the minimum length for a residential service entrance conductor?
24"

What is the minimum length for a commercial service entrance conductor?
36"

What is the vertical clearance from ground for servicedrops over spaces and ways to subject to pedestrians?
12 feet

What is the vertical clearance from ground for servicedrops over driveways, parking lots, and alleys?
16 feet

What is the vertical clearance from ground for servicedrops over other land traversed by vehicles?
16 feet

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

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 Demand
The average value of power or related quantity over a specified interval of time.

What is the min/max height for single meter installations. (final grade to meter center)
4' min, 6' max

What is the min/max height for multiple indoor meter installations. (final grade to meter center)
2' min/6.5' max

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

How many services (delivery points) per building?
 Only 1 except for
  emergency lighting
  optional standby systems
  parallel power production systems
  capacity requirements

Who installs and maintains the point of attachment?
The customer

What is the min/max height for multiple outdoor meter installations. (final grade to meter center
3' min / 6.5' max

What are the minimum depths of working space in front of metering equipment?
 3'
 3' 6"
 4'
 Depending on material (how fire proof) NEC mandates.

Do all meters need to be installed outdoors unless approved by the meter department?
Yes

Underground temporary service ground rods will be installed by the customer within all utility easements. T or F
 False.
 Must be outside utility easements (pg 43)

What are the 3 sides of a right triangle?
Hypotenuse, Adjacent, Opposite.

Using Trig functions, prove phase to phase voltage on a Wye system.

Using Pythagorean Theorem, prove wildleg voltage on a Delta system.

What is the formula to determine "True Power"? (solve problem)
E x I x Cosine theta = Watts

What is the formula to determine "Apparent Power"? (solve problem)
VA(volt amps)=E x I

Solve 4 problems using trig functions.

Draw Abase and Socket
FM1, FM2, FM12, FM14, FM15, FM16

Draw and connect applicable Abase and Socket meters for:
Single phase delta bank
4W3phase Delta bank
4W3phase Wye bank



R_{g} formula
R_{r} x R_{s}

Transformer Factor formula
TF= CTR x PTR

Know missing values for:
CR10
TM10, TM20, TM30
SC40, SC60

