Electro Industries Shark 200 User manual
Shark
®
200 & 200T
LOW-COST HIGH PERFORMANCE MULTIFUNCTION ELECTRICITY METER
Installation & Operation Manual
Revision 1.09
December 2, 2008
Doc #: E149701 V1.09
e
Electro Industries/GaugeTech
1800 Shames Drive
Westbury, New York 11590
Tel: 516-334-0870 uFax: 516-338-4741
“The Leader in Power Monitoring and Control”
Shark®200 & 200T Meter
Installation and Operation Manual
Version 1.09
Published by:
Electro Industries/GaugeTech
1800 Shames Drive
Westbury, NY 11590
All rights reserved. No part of this
publication may be reproduced or
transmitted in any form or by any
means, electronic or mechanical,
including photocopying, recording,
or information storage or retrieval
systems or any future forms of
duplication, for any purpose other
than the purchaser’s use, without
the expressed written permission of
Electro Industries/GaugeTech.
© 2008
Electro Industries/GaugeTech
Shark®is a registered trademark of
Electro Industries/Gauge Tech.
Printed in the United States of
America.
eElectro Industries/GaugeTech Doc # E149701 i
eElectro Industries/GaugeTech Doc # E149701 ii
Customer Service and Support
Customer support is available 9:00 am to 4:30 pm, eastern standard time, Monday through Friday.
Please have the model, serial number and a detailed problem description available. If the problem
concerns a particular reading, please have all meter readings available. When returning any merchandise
to EIG, a return materials authorization number is required. For customer or technical assistance, repair
or calibration, phone 516-334-0870 or fax 516-338-4741.
Product Warranty
Electro Industries/GaugeTech warrants all products to be free from defects in material and workmanship
for a period of four years from the date of shipment. During the warranty period, we will, at our option,
either repair or replace any product that proves to be defective.
To exercise this warranty, fax or call our customer-support department. You will receive prompt
assistance and return instructions. Send the instrument, transportation prepaid, to EIG at 1800 Shames
Drive, Westbury, NY 11590. Repairs will be made and the instrument will be returned.
Limitation of Warranty
This warranty does not apply to defects resulting from unauthorized modification, misuse, or use for any
reason other than electrical power monitoring. The Shark®200 Meter is not a user-serviceable product.
Our products are not to be used for primary over-current protection. Any protection feature in our
products is to be used for alarm or secondary protection only.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. ELECTRO INDUSTRIES/GAUGETECH
SHALL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL OR CONSEQUENTIAL
DAMAGES ARISING FROM ANY AUTHORIZED OR UNAUTHORIZED USE OF ANY
ELECTRO INDUSTRIES/GAUGETECH PRODUCT. LIABILITY SHALL BE LIMITED
TO THE ORIGINAL COST OF THE PRODUCT SOLD.
Statement of Calibration
Our instruments are inspected and tested in accordance with specifications published by Electro
Industries/GaugeTech. The accuracy and a calibration of our instruments are traceable to the National
Institute of Standards and Technology through equipment that is calibrated at planned intervals by
comparison to certified standards.
Disclaimer
The information presented in this publication has been carefully checked for reliability; however, no
responsibility is assumed for inaccuracies. The information contained in this document is subject to
change without notice.
This symbol indicates that the operator must refer to an explanation in the operating
instructions. Please see Chapter 4, Electrical Installation, for important safety
information regarding installation and hookup of the Shark®200 Meter.
eElectro Industries/GaugeTech Doc # E149701 iii
About Electro Industries/GaugeTech
Founded in 1973 by engineer and inventor Dr. Samuel Kagan, Electro Industries/GaugeTech changed the
face of power monitoring forever with its first breakthrough innovation: an affordable, easy-to-useAC
power meter.
Thirty years later, Electro Industries/GaugeTech, the leader in Web-Accessed Power Monitoring,
continues to revolutionize the industry with the highest quality, cutting edge power monitoring and
control technology on the market today. An ISO 9001:2000 certified company, EIG sets the industry
standard for advanced power quality and reporting, revenue metering and substation data acquisition and
control. EIG products can be found on site at virtually all of today’s leading manufacturers, industrial
giants and utilities.
All EIG products are designed, manufactured, tested and calibrated at our facility in Westbury, New
York.
eElectro Industries/GaugeTech Doc # E149701 iv
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Chapter 1
Three-Phase Power Measurement
This introduction to three-phase power and power measurement is intended to provide only a brief overview of the
subject. The professional meter engineer or meter technician should refer to more advanced documents such as the
EEI Handbook for Electricity Metering and the application standardsfor more in-depth and technical coverage of
the subject.
1.1: Three-Phase System Configurations
Three-phase power is most commonly used in situations where large amounts of power will be used because it is
a more effective way to transmit the power and because it provides a smoother delivery of power to the end load.
There are two commonly used connections for three-phase power, a Wye connection or a Delta connection. Each
connection has several different manifestations in actual use.When attempting to determine the type of connec-
tion in use, it is a good practice to follow the circuit back to the transformer that is serving the circuit. It is often
not possible to conclusively determine the correct circuit connection simply by counting the wires in the service or
checking voltages. Checking the transformer connection will provide conclusive evidence of the circuit
connection and the relationships between the phase voltages and ground.
1.1.1: Wye Connection
The Wye connection is so called because when you look at the phase relationships and the winding relationships
between the phases it looks like aY (wye). Fig. 1.1 depicts the winding relationships for a Wye-connected service.
In a Wye service the neutral (or center point of the wye) is typically grounded. This leads to common voltages of
208/120 and 480/277 (where the rst number represents the phase-to-phase voltage and the second number repre-
sents the phase-to-ground voltage).
Phase A
Phase B
Phase C
Figure 1.1: Three-Phase Wye Winding
Relationship
Figure 1.1: Three-Phase Wye Winding
The three voltages are separated by 120 degrees electrically. Under balanced load conditions with unity power fac-
tor the currents are also separated by 120 degrees. However, unbalanced loads and other conditions can cause the
currents to depart from the ideal 120 degree separation.
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Three-phase voltages and currents are usually represented with a phasor diagram.Aphasor diagram for the typical
connected voltages and currents is shown in Figure 1.2.
Vcn Ic
Van
Ib Ia
Vbn
Fig 1.2: Phasor Diagram ShowingThree-phase Voltages and Currents
The phasor diagram shows the 120 degree angular separation between the phase voltages. The phase-to-phase volt-
age in a balanced three-phase Wye system is 1.732 times the phase-to-neutral voltage. The center point of the Wye
is tied together and is typically grounded. Table 1.1 shows the common voltages used in the United States for Wye-
connected systems.
Phase-to-Ground Voltage Phase-to-Phase Voltage
120 Volts 208 Volts
277 Volts 480 Volts
2,400 Volts 4,160 Volts
7,200 Volts 12,470 Volts
7,620 Volts 13,200 Volts
Table 1.1: Common Phase Voltages on Wye Services
Usually a Wye-connected service will have four wires; three wires for the phases and one for the neutral. The three-
phase wires connect to the three phases (as shown in Fig. 1.1). The neutral wire is typically tied to the ground or
center point of the wye (refer to Figure 1.1).
In many industrial applications the facility will be fed with a four-wire Wye service but only three wires will be run
to individual loads. The load is then often referred to as a delta-connected load but the service to the facility is still
a Wye service; it contains four wires if you trace the circuit back to its source (usually a transformer). In this type
of connection the phase to ground voltage will be the phase-to-ground voltage indicated in Table 1.1, even though a
neutral or ground wire is not physically present at the load. The transformer is the best place to determine the circuit
connection type because this is a location where the voltage reference to ground can be conclusively identied.
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1.1.2: Delta Connection
Delta connected services may be fed with either three wires or four wires. In a three-phase Delta service the load
windings are connected from phase-to-phase rather than from phase-to-ground. Figure 1.3 shows the physical load
connections for a Delta service.
Phase A
Phase B
Phase C
Figure 1.3: Three-Phase Delta Winding Relationship
In this example of a Delta service, three wires will transmit the power to the load. In a true Delta service, the phase-
to-ground voltage will usually not be balanced because the ground is not at the center of the delta.
Fig. 1.4 shows the phasor relationships between voltage and current on a three-phase Delta circuit.
In many Delta services, one corner of the delta is grounded. This means the phase to ground voltage will be zero for
one phase and will be full phase-to-phase voltage for the other two phases. This is done for protective purposes.
Vab
Vbc
Vca
Ia
Ib
Ic
Figure 1.4: Phasor diagram showing three-phase voltages, currents delta connected.
Another common Delta connection is the four-wire, grounded delta used for lighting loads. In this connection the
center point of one winding is grounded. On a 120/240 volt, four-wire, grounded Delta service, the phase-to-ground
voltage would be 120 volts on two phases and 208 volts on the third phase. Figure 1.5 shows the phasor diagram for
the voltages in a three-phase, four-wire Delta system.
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Vca
120 V Vnc
Vbc
Vcn
Vbn
120 V
Vab 200 V
Fig 1.5: Phasor Diagram showing Three-phase, Four-wire Delta Connected System
1.1.3: Blondell’s Theorem and Three Phase Measurement
In 1893 an engineer and mathematician named Andre E. Blondell set forth the rst scientic basis for poly phase
metering. His theorem states:
If energy is supplied to any system of conductors through N wires, the total power in the system is given by the
algebraic sum of the readings of N Wattmeters so arranged that each of the N wires contains one current coil, the
corresponding potential coil being connected between that wire and some common point. If this common point is on
one of the N wires, the measurement may be made by the use of N-1 Wattmeters.
The theorem may be stated more simply, in modern language, as follows:
In a system of N conductors, N-1 meter elements will measure the power or energy taken provided that all the
potential coils have a common tie to the conductor in which there is no current coil.
Three-phase power measurement is accomplished by measuring the three individual phases and adding them to-
gether to obtain the total three phase value. In older analog meters, this measurement was accomplished using up
to three separate elements. Each element combined the single-phase voltage and current to produce a torque on the
meter disk.All three elements were arranged around the disk so that the disk was subjected to the combined torque
of the three elements.As a result the disk would turn at a higher speed and register power supplied by each of the
three wires.
According to Blondell’s Theorem, it was possible to reduce the number of elements under certain conditions. For
example, a three-phase, three-wire Delta system could be correctly measured with two elements (two potential coils
and two current coils) if the potential coils were connected between the three phases with one phase in common.
In a three-phase, four-wireWye system it is necessary to use three elements. Three voltage coils are connected be-
tween the three phases and the common neutral conductor.Acurrent coil is required in each of the three phases.
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In modern digital meters, Blondell’s Theorem is still applied to obtain proper metering.The difference in modern
meters is that the digital meter measures each phase voltage and current and calculates the single-phase power for
each phase. The meter then sums the three phase powers to a single three-phase reading.
Some digital meters calculate the individual phase power values one phase at a time. This means the meter samples
the voltage and current on one phase and calculates a power value. Then it samples the second phase and calculates
the power for the second phase. Finally, it samples the third phase and calculates that phase power.After sampling all
three phases, the meter combines the three readings to create the equivalent three-phase power value. Using math-
ematical averaging techniques, this method can derive a quite accurate measurement of three-phase power.
More advanced meters actually sample all three phases of voltage and current simultaneously and calculate the
individual phase and three-phase power values. The advantage of simultaneous sampling is the reduction of error
introduced due to the difference in time when the samples were taken.
Phase A
Phase B
Phase C
Figure 1.6: Three-Phase Wye Load illustrating Kirchhoff’s Law
and Blondell’s Theorem
Node “n”
A
B
N
C
Blondell’s Theorem is a derivation that results from Kirchhoff’s Law. Kirchhoff’s Law states that the sum of the
currents into a node is zero.Another way of stating the same thing is that the current into a node (connection point)
must equal the current out of the node. The law can be applied to measuring three-phase loads. Figure 1.6 shows a
typical connection of a three-phase load applied to a three-phase, four-wire service. Krichhoff’s Laws hold that the
sum of currentsA, B, C and N must equal zero or that the sum of currents into Node “n” must equal zero.
If we measure the currents in wiresA, B and C, we then know the current in wire N by Kirchhoff’s Law and it is not
necessary to measure it. This fact leads us to the conclusion of Blondell’s Theorem that we only need to measure
the power in three of the four wires if they are connected by a common node. In the circuit of Figure 1.6 we must
measure the power ow in three wires. This will require three voltage coils and three current coils (a three element
meter). Similar gures and conclusions could be reached for other circuit congurations involving Delta-connected
loads.
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1.2: Power, Energy and Demand
It is quite common to exchange power, energy and demand without differentiating between the three. Because this
practice can lead to confusion, the differences between these three measurements will be discussed.
Power is an instantaneous reading. The power reading provided by a meter is the present ow of watts. Power is
measured immediately just like current. In many digital meters, the power value is actually measured and calculated
over a one second interval because it takes some amount of time to calculate the RMS values of voltage and current.
But this time interval is kept small to preserve the instantaneous nature of power.
Energy is always based on some time increment; it is the integration of power over a dened time increment. Energy
is an important value because almost all electric bills are based, in part, on the amount of energy used.
Typically, electrical energy is measured in units of kilowatt-hours (kWh).Akilowatt-hour represents a constant load
of one thousand watts (one kilowatt) for one hour. Stated another way, if the power delivered (instantaneous watts)
is measured as 1,000 watts and the load was served for a one hour time interval then the load would have absorbed
one kilowatt-hour of energy.Adifferent load may have a constant power requirement of 4,000 watts. If the load were
served for one hour it would absorb four kWh. If the load were served for 15 minutes it would absorb ¼ of that total
or one kWh.
Figure 1.7 shows a graph of power and the resulting energy that would be transmitted as a result of the illustrated
power values. For this illustration, it is assumed that the power level is held constant for each minute when a mea-
surement is taken. Each bar in the graph will represent the power load for the one-minute increment of time. In real
life the power value moves almost constantly.
The data from Figure 1.7 is reproduced in Table 2 to illustrate the calculation of energy. Since the time increment of
the measurement is one minute and since we specied that the load is constant over that minute, we can convert the
power reading to an equivalent consumed energy reading by multiplying the power reading times 1/60 (converting
the time base from minutes to hours).
Time (minutes)
Kilowatts
20
40
60
80
100
Figure 1.7: Power use over time
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Time Interval
(Minute) Power (kW) Energy (kWh) Accumulated
Energy (kWh)
1 30 0.50 0.50
2 50 0.83 1.33
3 40 0.67 2.00
4 55 0.92 2.92
5 60 1.00 3.92
6 60 1.00 4.92
7 70 1.17 6.09
8 70 1.17 7.26
9 60 1.00 8.26
10 70 1.17 9.43
11 80 1.33 10.76
12 50 0.83 12.42
13 50 0.83 12.42
14 70 1.17 13.59
15 80 1.33 14.92
Table 1.2: Power and energy relationship over time
As in Table 1.2, the accumulated energy for the power load prole of Figure 1.7 is 14.92 kWh.
Demand is also a time-based value. The demand is the average rate of energy use over time. The actual label for
demand is kilowatt-hours/hour but this is normally reduced to kilowatts. This makes it easy to confuse demand with
power. But demand is not an instantaneous value. To calculate demand it is necessary to accumulate the energy read-
ings (as illustrated in Figure 1.7) and adjust the energy reading to an hourly value that constitutes the demand.
In the example, the accumulated energy is 14.92 kWh. But this measurement was made over a 15-minute interval.To
convert the reading to a demand value, it must be normalized to a 60-minute interval. If the pattern were repeated for
an additional three 15-minute intervals the total energy would be four times the measured value or 59.68 kWh.The
same process is applied to calculate the 15-minute demand value. The demand value associated with the example
load is 59.68 kWh/hr or 59.68 kWd. Note that the peak instantaneous value of power is 80 kW, signicantly more
than the demand value.
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Figure 1.8 shows another example of energy and demand. In this case, each bar represents the energy consumed in a
15-minute interval. The energy use in each interval typically falls between 50 and 70 kWh. However, during two in-
tervals the energy rises sharply and peaks at 100 kWh in interval number 7. This peak of usage will result in setting
a high demand reading. For each interval shown the demand value would be four times the indicated energy reading.
So interval 1 would have an associated demand of 240 kWh/hr. Interval 7 will have a demand value of 400 kWh/hr.
In the data shown, this is the peak demand value and would be the number that would set the demand charge on the
utility bill.
Intervals
Kilowatt-hours
20
40
60
80
100
Figure 1.8: Energyuse and demand
Figure 1.8: Energy Use and Demand
As can be seen from this example, it is important to recognize the relationships between power, energy and demand
in order to control loads effectively or to monitor use correctly.
1.3: Reactive Energy and Power Factor
The real power and energy measurements discussed in the previous section relate to the quantities that are most used
in electrical systems. But it is often not sufcient to only measure real power and energy. Reactive power is a criti-
cal component of the total power picture because almost all real-life applications have an impact on reactive power.
Reactive power and power factor concepts relate to both load and generation applications. However, this discussion
will be limited to analysis of reactive power and power factor as they relate to loads. To simplify the discussion,
generation will not be considered.
Real power (and energy) is the component of power that is the combination of the voltage and the value of cor-
responding current that is directly in phase with the voltage. However, in actual practice the total current is almost
never in phase with the voltage. Since the current is not in phase with the voltage, it is necessary to consider both the
inphase component and the component that is at quadrature (angularly rotated 90 degrees or perpendicular) to the
voltage. Figure 1.9 shows a single-phase voltage and current and breaks the current into its in-phase and quadrature
components.
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V
I
I
R
I
X
Figure 1.9: Voltage and complex current
Angle q
The voltage (V) and the total current (I) can be combined to calculate the apparent power or VA. The voltage and the
in-phase current (IR) are combined to produce the real power or watts. The voltage and the quadrature current (IX)
are combined to calculate the reactive power.
The quadrature current may be lagging the voltage (as shown in Figure 1.9) or it may lead the voltage. When the
quadrature current lags the voltage the load is requiring both real power (watts) and reactive power (VARs). When
the quadrature current leads the voltage the load is requiring real power (watts) but is delivering reactive power
(VARs) back into the system; that is VARs are owing in the opposite direction of the real power ow.
Reactive power (VARs) is required in all power systems.Any equipment that uses magnetization to operate requires
VARs. Usually the magnitude of VARs is relatively low compared to the real power quantities. Utilities have an
interest in maintaining VAR requirements at the customer to a low value in order to maximize the return on plant
invested to deliver energy. When lines are carrying VARs, they cannot carry as many watts. So keeping the VAR
content low allows a line to carry its full capacity of watts. In order to encourage customers to keep VAR require-
ments low, most utilities impose a penalty if the VAR content of the load rises above a specied value.
A common method of measuring reactive power requirements is power factor. Power factor can be dened in two
different ways. The more common method of calculating power factor is the ratio of the real power to the apparent
power. This relationship is expressed in the following formula:
Total PF = real power / apparent power = watts/VA
This formula calculates a power factor quantity known as Total Power Factor. It is called Total PF because it is based
on the ratios of the power delivered. The delivered power quantities will include the impacts of any existing har-
monic content. If the voltage or current includes high levels of harmonic distortion the power values will be affected.
By calculating power factor from the power values, the power factor will include the impact of harmonic distortion.
In many cases this is the preferred method of calculation because the entire impact of the actual voltage and current
are included.
Asecond type of power factor is Displacement Power Factor. Displacement PF is based on the angular relationship
between the voltage and current. Displacement power factor does not consider the magnitudes of voltage, current
or power. It is solely based on the phase angle differences.As a result, it does not include the impact of harmonic
distortion.
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Electro Industries/Gauge Tech
Doc# E149701
1-10
Displacement power factor is calculated using the following equation:
Displacement PF = cos q, where qis the angle between the voltage and the current (see Fig. 1.9).
In applications where the voltage and current are not distorted, the Total Power Factor will equal the
Displacement Power Factor. But if harmonic distortion is present, the two power factors will not be equal.
1.4: Harmonic Distortion
Harmonic distortion is primarily the result of high concentrations of non-linear loads. Devices such as computer
power supplies, variable speed drives and uorescent light ballasts make current demands that do not match the
sinusoidal waveform ofAC electricity.As a result, the current waveform feeding these loads is periodic but not
sinusoidal. Figure 1.10 shows a normal, sinusoidal current waveform. This example has no distortion.
A Phase Current
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-1000
-500
0
500
1000
1500
133 65
Figure 1.10: Non-distorted current waveform
Figure 1.11 shows a current waveform with a slight amount of harmonic distortion. The waveform is still periodic
and is uctuating at the normal 60 Hz frequency. However, the waveform is not a smooth sinusoidal form as seen in
Figure 1.10.
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