Brymen PowerClamp BM151 User manual
USER'S MANUAL
BM151, BM152, BM155, &
BM351
PowerClamp
TM
Series
1
1) SAFETY
This manual contains information and warnings that must be followed for operating the
instrument safely and maintaining the instrument in a safe operating condition. If the
instrument is used in a manner not specified by the manufacturer, the protection
provided by the instrument may be impaired.
The meter protection rating, against the users, is double insulation per IEC61010 1 2nd
Ed., EN61010 1 2nd Ed., UL61010 1 2nd Ed., CAN/CSA C22.2 No. 61010.1 0.92,
IEC61010 2 032, EN61010 2 032, UL61010B 2 032, & CAN/CSA C22.2 No.
61010 2 032 04:
Measurement Category III 600V AC & DC.
Per IEC61010 1 2nd Ed. (2001) Measurement Category
Measurement Category IV (CAT IV) is for measurements performed at the source of
the low voltage installation. Examples are electricity meters and measurements on
primary overcurrent protection devices and ripple control units.
Measurement Category III (CAT III) is for measurements performed in the building
installation. Examples are measurements on distribution boards, circuit breakers,
wiring, including cables, bus bars, junction boxes, switches, socket outlets in the fixed
installation, and equipment for industrial use and some other equipment, for example,
stationary motors with permanent connection to the fixed installation.
Measurement Category II (CAT II) is for measurements performed on circuits directly
connected to the low voltage installation. Examples are measurements on household
appliances, portable tools and similar equipment.
TERMS IN THIS MANUAL
WARNING identifies conditions and actions that could result in serious injury or even
death to the user.
CAUTION identifies conditions and actions that could cause damage or malfunction
in the instrument.
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WARNING
To reduce the risk of fire or electric shock, do not expose this product to rain or
moisture. The meter is intended only for indoor use.
To avoid electrical shock hazard, observe the proper safety precautions when working
with voltages above 60 VDC or 30 VAC rms. These voltage levels pose a potential
shock hazard to the user.
Keep your hands/fingers behind the hand/finger barriers (of the meter and the test
leads) that indicate the limits of safe access of the hand held part during measurement.
Inspect test leads, connectors, and probes for damaged insulation or exposed metal
before using the instrument. If any defects are found, replace them immediately.
This Clamp on meter is designed to apply around or remove from uninsulated
hazardous live conductors. But still, individual protective equipment must be used if
hazardous live parts in the installation where measurement is to be carried out could be
accessible.
CAUTION
Disconnect the test leads from the test points before changing meter functions.
INTERNATIONAL ELECTRICAL SYMBOLS
!
!!
!
Caution ! Refer to the explanation in this Manual
Caution ! Risk of electric shock
Earth (Ground)
Double Insulation or Reinforced insulation
Fuse
AC Alternating Current
DC Direct Current
Application around and removal from hazardous live conductors is permitted
2) CENELEC Directives
The instruments conform to CENELEC Low voltage directive 2006/95/EC and
Electromagnetic compatibility directive 2004/108/EC
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3) PRODUCT DESCRIPTION
Note: Top of the line model is used as representative for illustration purposes. Please
refer to your respective model for function availability.
1) Transformer Clamp Jaws for AC
current magnetic field pick up
2) Jaw marking lines for ACA (& thus
Power) position error indication
3) Hand/Finger Barrier to indicate the
limits of safe access to the jaws
during current measurements
4) Push buttons for special functions
& features
5) Input Jack for all functions
EXCEPT non invasive ACA current
(& thus Power) function
6) Common (Ground reference) Input
Jack for all functions EXCEPT
non invasive ACA current (& thus
Power) function
7) Slide switch Selector to turn the
power ON/OFF and Select a function
8) LCD display
9) Jaw trigger for opening the
transformer clamp jaws
10) Jaw center Indicators, at where
best ACA (& thus Power) accuracy is
specified
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4) OPERATION
CAUTION: Before and after hazardous voltage measurements, test the voltage
function on a known source such as line voltage to determine proper meter functioning.
AutoVATM function
Set the slide switch function selector to the position.
●With no input, the meter displays “Auto” when it is ready.
●With no ACA current input via the jaws but a voltage signal above the nominal
threshold of DC 2.4V or AC 30V (40Hz ~ 500Hz) up to the rated 600V is present on
V COM terminals, the meter displays the voltage value in appropriate DC or AC,
whichever larger in peak magnitude. LCD annunciator “dc” or “ ” turns on
respectively.
●On the contrary, with no voltage signal present on V COM terminals but a ACA
current signal above the nominal threshold of AC 1A (40Hz ~ 500Hz) up to the rated
1000A is input via the jaws, the meter displays the ACA current value. LCD annunciator
“ ” turns on accordingly.
●The Auto VA feature stays at the auto selected function as long as its signal remains
above the specified threshold. Press SELECT button momentarily to manually select
thru the functions ACA, ACV, DCV and then goes back to Auto VA.
CAUTION (Application and removal of the Clamp-on meter)
● or non-invasive ACA current measurements, press the jaw trigger and clamp the
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jaws around only one single conductor of a circuit for load current measurement.
Make sure the jaws are completely closed, or else it will introduce measurement errors.
Enclosing more than one conductor of a circuit will result in differential current
measurement (like identifying leakage current). Locate the conductor(s) at the Jaws
center as much as possible to get the best measuring accuracy. or removal, press the
jaw trigger and remove the jaws from the conductor(s).
●Adjacent current-carrying devices such as transformers, motors and conductor wires
will affect measurement accuracy. Keep the jaws away from them as much as possible
to minimize influence.
THD% F Total Harmonic Distortion Fundamental function (model 155 only)
THD% F = (Total Harmonics RMS / Fundamental RMS) x 100%
Total Harmonic Distortion Fundamental (THD% F) is the percentage ratio of the Total
Harmonics RMS value to the Fundamental RMS value of a voltage or current signal,
and is given by the above expression. An ideal sinusoidal waveform has a value of 0
THD%. A badly distorted sinusoidal waveform may have a much higher THD% value of
up to several hundreds.
When the meter is in ACV or ACA function, THD% F values of up to 99 THD% will be
displayed in the secondary mini display automatically. Press THD% F button
momentarily toggles THD% readings to main display to get full readings of up to 999.9
THD%.
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Line level Frequency function
When ACV or ACA function is auto selected or manual selected, press Hz button
momentarily toggles to Line level Frequency function. Frequency trigger levels vary
automatically with function ranges.
Peak rms mode
Peak-rms compares and displays the maximum RMS value of surge voltage or
current with durations as short as 65ms. When ACV or ACA function is auto selected
or manual selected, press and hold Peak-rms button for one second or more
toggles to this mode. The LCD annunciators “P ” & “Max” turn on.
Note:
Manually disable the APO feature (press & hold the HOLD button while setting the
slide switch function selector from any position to the position.) before using
Peak-rms mode for long term measurements.
HOLD mode
Hold mode freezes the display for later viewing. When any function is auto selected or
manual selected, press HOLD button momentarily toggles to this mode. The
annunciator “ ” turns on.
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Notes on Displacement Power Factor & Total Power Factor
●Introduction: Power is the rate of change of energy with respect to time (in terms of
voltage V and current A). Instantaneous (real) power w = vi where v is the
instantaneous voltage and i the instantaneous current. The average (real) power is the
mean of vi and is given by:
W = ω/2π∫vi dt , over the interval from 0 to 2π/ω
●Displacement Power actor (more traditional): Assuming V and A are pure
sinusoidal waveforms without harmonics (as in most traditional cases), that is, v = V
sinωt and i = I sin (ωt θ), the expression can be simplified to:
W = 1/2 x V x I x Cosθ where V and I are the peak values, θ is the
displacement power factor angle, and Cosθ is the displacement power factor. Using
RMS values, it is written as:
W = Vrms x Arms x Cosθ
Practically, in such cases without harmonics, θ is also called the phase shift angle of
the current A to the voltage V. An inductive circuit is said to have a lagging power factor
since current A lags voltage V (phase shift angle θ and thus Sinθ are both “+”),
and a capacitive circuit is said to have a leading power factor since current A leads
voltage V (phase shift angle θ and thus Sinθ are both “ ”).
●Total Power actor (encountering harmonics): When encountering distorted
waveforms with the presence of harmonics, however, the simplified power expression
should not be used since substituting the above mentioned pure sinusoidal V and A
functions cannot fulfill the actual conditions. Cosine of phase-shift angle (Cos
θ
), or
the displacement power factor, is no longer the only component constituting the overall
power factor. Harmonics do increase apparent power and thus decrease the overall
power factor. That is, the Total Power actor is actually affected by both phase-shift
angle and harmonics, and is given by the expression:
Total Power actor (P ) = Real Power (W) / Apparent Power (VA)
In order to improve overall system power factor, nowadays power system engineer
needs to address both phase shift and harmonics problems. Practically, harmonics
should be dealt with (e.g. filtering out) before phase shift to be corrected (e.g. installing
capacitors in parallel with inductive loads).
Power function
Set the slide switch function selector to the Power position.
●Default at last selected function. Press SELECT button momentarily selects between
W (real power), VAR (reactive power) & VA (apparent power) measurement functions.
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●PF (Total Power Factor) displays simultaneously in the secondary mini display.
Denoting efficiency, absolute PF value is adopted.
●“A lags” LCD annunciator turns on to indicate an inductive circuit, or Current A lags
Voltage V (i.e., phase shift angle θ is “+”).
On the contrary, together with significant PF values, WITHOUT turning on “A lags”
indicates a capacitive circuit, or Current A leads Voltage V (i.e., phase shift angle θ
is “ ”).
Note:
1. When measuring load circuits with power absorptions as in most applications,
positive W (Real Power) readings indicate correct measurement setups. Negative
readings (LCD annunciator “ “ turns on) indicate either the clamp on jaws direction or
the test leads polarity is reversed in such cases. Correct the setups to get proper
“A lags” indications.
2. When encountering largely distorted waveforms, “A lags” detection might be affected
due to the influence of harmonics. As mentioned, it is recommended to deal with (e.g.
filter out) harmonics before correcting phase shift problems.
●Measuring One or Single Phase Power Parameters:
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●Measuring 3-Phase 4-Wire
(3 4W) Power Parameters:
In both un balanced and balanced load cases, 3 Phase 4 Wire (3 4W) systems,
measure the phase to neutral powers kW1, kW2 and kW3 of each phase separately as
illustrated. System (total) power kWTotal is the summation of all three phase to neutral
powers. That is:
kWTotal = kW1 + kW2 + kW3 (for both un-balanced and balanced load cases)
In balanced load cases, 3 Phase 4 Wire (3 4W) systems, the system (total) power
parameters can be simplified to three times of any of the phase to neutral powers. That
is:
kWTotal = 3 x kW1 (for balanced load cases only)
kVATotal = 3 x kVA1 (for balanced load cases only)
kVARTotal = 3 x kVAR1 (for balanced load cases only)
This manual suits for next models
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