r meets the requirements for double insulation to IEC61010-2-032(1994),
EN61010-2-032(1995), UL3111-2-032(1999):

Category III 600 Volts ac and dc.

PER IEC61010 OVERVOLTAGE INSTALLATION CATEGORY
OVERVOLTAGE CATEGORY II
Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be
supplied from the fixed installation.
Note Examples include household, office, and laboratory appliances.
OVERVOLTAGE CATEGORY III
Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed installations.
Note Examples include switches in the fixed installation and some equipment for
industrial use with permanent connection to the fixed installation.
OVERVOLTAGE CATEGORY IV
Equipment of OVERVOLTAGE CATEGORY IV is for use at the origin of the installation.
Note Examples include electricity meters and primary over-current protection
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.
2
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.

Inspect test leads, connectors, and probes for damaged insulation or exposed metal
before using the instrument. If any defects are found, replace them immediately.

Do not touch test lead tips or the circuit being tested while power is applied to the circuit
being measured. To avoid accidental short circuit of bare (uninsulated) hazardous live
conductors or busbars, switch them off before insertion and removal of the current clamp
jaws. Contact with the conductor could result in electric shock. Keep your hands/fingers
behind the hand/finger barriers that indicate the limits of safe access of the meter and the
test leads during measurement.

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

2) CENELEC Directives
The instruments conform to CENELEC Low-voltage directive 73/23/EEC and
Electromagnetic compatibility directive 89/336/EEC
3

3) PRODUCT DESCRIPTION
This user's manual uses only representative model(s) for illustrations. Please refer
specification details for function availability to each model.

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
4
4) OPERATION



AutoVA
TM
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
For non-invasive ACA current measurements, press the jaw trigger and clamp the jaws
5
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 (like identifying
leakage current) measurement.
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 ACD-41PQ 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 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 up to 999.9
THD%.
6


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.
7
Notes on Displacement Power Factor & True 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
= /2vi dt , over the interval from 0 to 2/
Displacement Power Factor (more traditional): Assuming V and A are pure
sinusoidal waveforms without harmonics (as in most traditional cases), that is, v = V sin

t and i = I sin (t -), the expression can be simplified to:

W = 1/2 x V x I x Cos where V and I are the peak values, is the displacement
power factor angle, and Cos is the displacement power factor. Using RMS values, it is
written as:

W = V
rms
x A
rms
x Cos
Practically, in such cases without harmonics, 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 and thus Sin are both +), and a
capacitive circuit is said to have a leading power factor since current A leads voltage V
(phase-shift angle and thus Sin are both -).
True Power Factor (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 ), 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 True Power Factor is actually affected by both phase-shift
angle and harmonics, and is given by the expression:
True Power Factor (PF) = Real Power (V
rms
x A
rms
x Cos)/Apparent Power (V
trms
x
A
trms
)
In order to improve overall system power factor, nowadays power-system engineers
need 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 moment