Amprobe DM-4 User Manual

DM-4 Power Quality Recorder

DM-4 Power Quality Recorder

TABLE OF CONTENTS

1. PRECAUTIONS AND SAFETY MEASURES.............................................................................. 3

1.1 GENERAL................................................................................................................... 3

1.2 PRELIMINARY INSTRUCTIONS ............................................................................... 3

1.3 DURING USE.............................................................................................................. 4

1.4 AFTER USE................................................................................................................ 4

2.GENERAL DESCRIPTION ........................................................................................................... 5

2.1 INTRODUCTION ........................................................................................................ 5

2.2 FUNCTIONS............................................................................................................... 5

3. PREPARING THE INSTRUMENT................................................................................................ 6

3.1 INITIAL CHECK.......................................................................................................... 6

3.2 INSTRUMENT POWER SUPPLY............................................................................... 6

3.3 CALIBRATION............................................................................................................ 6

3.4 STORAGE.................................................................................................................. 7

4. HOW TO OPERATE..................................................................................................................... 7

4.1 INSTRUMENT: DESCRIPTION................................................................................. 7

4.2 KEYBOARD: DESCRIPTION.................................................................................... 7

4.3 USING THE DM-4 WITH THE REMOTE USER INTERFACE (PDA)........................ 8

4.4 DISPLAY DESCRIPTION OF THE REMOTE USER INTERFACE (PDA................... 9

4.4.1 VIEW REAL TIME DATA........................................................................................ 9

4.4.2 SETUP ANEW RECORDING SESSION................................................................13

5. MAIN MENU................................................................................................................................15

6. RECORDING CONFIGURATION.............................................................................................

7. STARTING A RECORDING

4.4.3 SET DATE AND TIME FOR AUTOMATIC RECORDING SESSION.....................14

5.1 INITIAL SETTINGS....................................................................................................15

5.1.1 HOW TO SET THE DATE AND TIME?...................................................................16

5.2 DEFAULT SETTINGS: ANALYZER CONFIG.............................................................16

5.2.1 HOW TO SET THE TYPE OF ELECTRICAL SYSTEM UNDER TEST.................17

5.3 BASIC SETTING: RECORDER CONFIG..................................................................18

5.3.1 MDL PARAMETER SETUP.....................................................................................18

5.3.2 MDL VOLTAGE ANOMALIES.................................................................................18

5.4 ADVANCED SETTING: RECORDER CONFIGURATION..........................................19

5.4.1 SETTING THE PARAMETERS INDIVIDUALLY......................................................20

5.4.2 ADVANCED MDL PARAMETER SETUP.................................................................20

5.4.3 SET UP THE PARAMETERS FOR VOLTAGE........................................................20

5.4.4 SETUP THE PARAMETERS FOR CURRENT........................................................21

5.4.5 SETUP THE PARAMETERS FOR POWER............................................................21

5.4.6 SETUP THE PARAMETERS FOR VOLTAGE HARMONICS..................................22

5.4.7 SETUP THE PARAMETERS FOR CURRENT HARMONICS.................................23

5.5 DOWNLOAD DATA....................................................................................................24

5.5.1 DOWNLOAD DATA WITH THE REMOTE USER INTERFACE (PDA)...................24

5.5.2 VIEW DOWNLOADED DATA..................................................................................25

5.5.3 RECORDING INFORMATION................................................................................25

5.5.4 DELETE SESSION.................................................................................................26

5.5.5 RESET....................................................................................................................29

........................................................................................................30

.

.

30

DM-4 Power Quality Recorder

8. RECORDING IN PROCESS........................................................................................................32

9. STOPPING A RECORDING........................................................................................................33

10. CONNECTING THE INSTRUMENT TO A PC...........................................................................34

11. MEASURING PROCEDURES..................................................................................................35

12. MAINTENANCE........................................................................................................................40

13. TECHNICAL SPECIFICATIONS..............................................................................................41

14. APPENDIX 1 – RECORDABLE PARAMETERS: SYMBOLS.................................................46

15. APPENDIX 2 – THEORETICAL OUTLINES............................................................................47

16. AFTER-SALE SERVICE..........................................................................................................56

9.1 STOP A RECORDING WITH THE REMOTE USER INTERFACE (PDA).................33

9.2 STOPA RECORDING WITH THE DOWNLOAD SUITE............................................33

11.1 USING THE INSTRUMENT IN A SINGLE PHASE SYSTEM..................................35

11.2 USING THE INSTRUMENT IN A THREE PHASE

4- WIRE SYSTEM (WYE)........................................................................................36

11.3 USING THE INSTRUMENT IN A THREE PHASE 3- WIRE

SYSTEM (DELTA).......................................................................................................38

12.1 GENERAL................................................................................................................40

12.2 BATTERY REPLACEMENT.....................................................................................40

13.1 FEATURES............................................................................................................. 41

13.1.1 VOLTAGE MEASUREMENT................................................................................41

13.1.2 VOLTAGE ANOMALIES DETECTION (MANUAL SELECTION OF

RANGE) VOLTAGE.................................................................................................41

13.1.3 CURRENT MEASUREMENT (USING EXTERNALTRANSDUCER)................. ..41

13.1.4 POWER MEASUREMENT (COS

13.1.5 COSΘ MEASUREMENT.....................................................................................42

13.1.6 MEASUREMENT OF HARMONICS....................................................................43

13.1.7 TEMPERATURE DRIFT....................................................................................... 43

13.1.8 SAFETY............................................................................................................... 43

13.1.9 GENERAL CHARACTERISTICS......................................................................... 44

13.2 ENVIRONMENT...................................................................................................... 44

13.2.1 OPERATING CONDITIONS................................................................................ 44

13.3 ACCESSORIES...................................................................................................... 45

13.3.1 STANDARD ACCESSORIES...............................................................................45

15.1 VOLTAGE ANOMALIES (VOLTAGE SAG AND SURGE; SPIKE).......................... .47

15.2 VOLTAGE AND CURRENT HARMONICS..............................................................48

15.2.1 THEORY............................................................................................................. . 48

15.2.2 LIMIT VALUES FOR HARMONICS.....................................................................49

15.2.3 PRESENCE OF HARMONICS: CAUSES........................................................... 50

15.2.4 PRESENCE OF HARMONICS: CONSEQUENCES............................................50

15.3 POWER AND POWER FACTOR: DEFINITIONS...................................................51

15.3.1 CONVENTIONS ON POWERS AND POWER FACTORS..................................53

15.3.2 3 PHASE 3 WIRE SYSTEM..............................................................................54

15.4 MEASURING METHOD: OUTLINES......................................................................55

15.4.1 INTEGRATION PERIODS................................................................................... .55

15.4.2 POWER FACTOR CALCULATIONS.................................................................. ..55

ARRANTY............................................................................................................56

16.1 W

16.2 SERVICE................................................................................................................56

Θ: 0.5C – 0.5I).................................................42

DM-4 Power Quality Recorder

1. PRECAUTIONS AND SAFETY MEASURES

1.1 GENERAL

For your own safety and to avoid damaging the instrument we suggest you follow
the procedures hereby prescribed and to carefully read all the notes preceded by

the symbol m.

Before and during measurements please be very diligent in following instructions below:

• Do not measure voltage or current in wet or dusty places

• Do not measure in presence of gas, explosive materials or combustibles

• Do not touch the circuit under test if no measurement is being taken

• Do not touch exposed metal parts, unused terminals, circuits and so on

• Do not use the instrument if it seems to be malfunctioning

• Use only cables and accessories approved by Amprobe

The following symbols are used in this manual:

m Caution: keep to what is prescribed by the manual. An incorrect use could

damage the instrument or its components

c High voltage: risk of electric shock

1.2 PRELIMINARY INSTRUCTIONS

• This instrument has been designed for use in places with pollution class 2.

• It can be used for
voltage category III 600 V~ phase to phase / 346 V~ phase to earth and of excess

voltage category II 1000 V~ phase to phase / 577 V~ phase to earth.

voltage and current measurements in installations of excess

3

DM-4 Power Quality Recorder

• Please keep to the usual safety standards aimed at:

Protecting against dangerous currents;
Protecting the instrument against incorrect operations.

• Only the accessories supplied with the instrument guarantee compliance with the

safety standards. Accordingly, they must be in good condition and, if necessary,
they must be replaced with identical models.

• Do not take measurements on circuits exceeding the specified current and

voltage limits.

• Before connecting voltage leads and clamps to the circuit under test, make sure

that the circuit configuration has been selected.

1.3 DURING USE

Please read carefully:

CAUTION

Should you fail to keep to the prescribed instructions you could damage

m

the instrument and/or its components or endanger your safety.

• When the instrument is connected to the circuit under test, do not touch any

unused terminal.

• When measuring current, other currents located near the leads may affect the

measuring accuracy.

• When measuring current, always position the wire in the very middle of the jaws

in order to obtain the highest accuracy.

1.4 AFTER USE

• After use, turn off the instrument by pressing the ON/OFF push button.

• If you won’t be using the instrument for long periods of time, use the storage

instructions described in paragraph 3.4.

4

DM-4 Power Quality Recorder

2.GENERAL DESCRIPTION

2.1 INTRODUCTION

The DM-4 also referred to as the Modular Data Logger (MDL), addresses the needs
of the most demanding Power Quality professionals. The device incorporates full set
of measuring features crucial for complete Power Quality analysis. An innovative
Remote User Interface (PDA) allows safe, easy and convenient operation of the
device remotely. Remote User Interface (PDA) is also used for data viewing, analy­sis and transfer. Independently, the DM-4 can be used directly with a PC using
Download Suite software. Since the DM-4 does not have any control buttons on its
enclosure, it is protected against setup changes by unauthorized persons while the
device is recording, eliminating the need for password protection.

2.2 FUNCTIONS

The DM-4 is able to:

• Display in real time the electrical parameters of a single phase, two phase or
three-phase system (wye or delta) and the harmonic analysis of voltages and currents.

• Conduct a direct Energy measurement.

• Record simultaneously (pressing the RECORD key after a proper connection &

device configuration): RMS values of voltages, currents, corresponding harmonics;

active, reactive and apparent powers, power factor and cos

Θ; active, reactive and

apparent energies; voltage sag and surge with 14ms resolution; and voltage spike

with 100ns resolution.

It will be possible to analyze the recorded data by down-

loading the file using the Remote User Interface (PDA) or Download Suite.

• Record Data (pressing RECORD key) the sampled values of the Parameters

present at the instrument’s input.

It will be possible to analyze the recorded
data by downloading the file with the Remote User Interface (PDA) device
or a PC using the Download Suite.

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DM-4 Power Quality Recorder

3. PREPARING THE INSTRUMENT

3.1 INITIAL CHECK

This instrument has been checked before shipment from an electrical and mechan­ical point of view. All possible precautions have been taken in order to deliver it in
perfect condition. Notwithstanding, on receipt of the instrument we suggest that
you check it summarily to make sure that no damage has occurred in transit.
Should you find irregularities, please contact the carrier immediately. Furthermore,
make sure that the parcel contains all the accessories and parts listed on Table

13.3.1. In case of discrepancies, please contact your dealer. Should it be neces­sary to return the instrument to the supplier, please keep to the instructions given
at paragraph 16.1.

3.2 INSTRUMENT POWER SUPPLY

The instrument can be powered by:

• 8 batteries 1.5V AA located in the compartment on the back of the instrument

• An external power supply code DM-4EXTPS supplied with the instrument
(standard accessory).

CAUTION

m

3.3 CALIBRATION

The instrument complies with the standards mentioned in this manual. Its perform­ance is guaranteed for one year from the purchase date.

For recordings ALWAYS use the external power supply (even though the
instrument allows the operator to perform a recording using internal batteries).

6

DM-4 Power Quality Recorder

3.4 STORAGE

For long time storage, please remove batteries to prevent leakage into the unit. Store
unit in a safe location with room temperature conditions. To guarantee accurate
measurements after a long storage period in severe environmental conditions, wait
until the instrument resumes its normal conditions (see environmental conditions
listed in paragraph 13.2).

4. HOW TO OPERATE

4.1 INSTRUMENT: DESCRIPTION

4

5

6

7

3

8

2

LEGEND

1. Voltage Inputs

2. Current Inputs

3. Infrared Ports

4. External Power
Supply Plug

5. RS232 Serial Connector

6. ON/OFF Push Button

7. Record Push Button

8. Reset Push Button

1

4.2 KEYBOARD: DESCRIPTION

The following keys are available:

ON/OFF: turning on – turning off / (Green LED for AC and Red LED for Battery)
RECORD: to start/stop manually a recording

RESET: to reset the unit

7

DM-4 Power Quality Recorder

4.3 USING THE DM-4 WITH THE REMOTE USER INTERFACE (PDA)

• Connect the Remote User Interface (PDA) to the DM-4 using the provided cable

• Turn ON the DM-4 by pressing on the ON/OFF push button

• Turn ON the Remote User Interface (PDA) by pressing the power button

• Click on the MDL (Modular Data Logger) icon

Click MDL

icon to
enter the
program.

8

DM-4 Power Quality Recorder

4.4 DISPLAY DESCRIPTION OF THE REMOTE USER INTERFACE (PDA)

Download the
recorded files.

View the downloaded files.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Display real time information
of the monitored system.

Allow the user to setup
recording sessions with the

desired configuration.
Delete recording or
downloaded files.

Delete Session Device Status

Display the status of the

device.

4.4.1 View Real Time Data

When monitoring an electrical system in real time, the user needs to know the
type of system configuration the device is hooked up to in order to have the
correct readings. Refer to section 11 for more information on the different types of
electrical system configurations.

• From the MDL Main Menu screen, click on View Real Time Data. The following
screen will appear.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session

R

TM Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:

P 60 Hz
P 1000 Amps

OK

• Select the desired electrical system configuration you want to monitor.

• Select the fundamental frequency of the system

• Select the type of clamp you are using with the DM-4 to monitor the
electrical system.

• Click OK to accept the system setup.

9

DM-4 Power Quality Recorder

• 1-Phase 2-wire, 60Hz System using 1000A clamp

MDL-Main Menu

View Real Time Data
Setup a New Recording Session

R

TM Setup

Phase Selection: P 1 Ø 2 W (Y)
Fund. Frequency:
Clamp Type:

P 60 Hz
P 1000 Amps

OK

• Select 1Ø2W, 60Hz, 1000A and then click OK. The following screen will appear:

Voltage & Current

V1: 116.13V __ l1: 3.96A

Back Voltage Current Power

• Once you get into this screen, you can get real time readings for voltage and
current and their associated waveforms and harmonics. You can also get
readings for power.

How to Monitor Voltage Only?

Click on the Voltage button located at the bottom of the screen. The voltage
reading for the monitoring phase will be displayed with its respective frequency.

Real Time Voltage

V1

Volt
(V) 0.00

Freq
(Hz) 0.00

Back Harm Scope

10

DM-4 Power Quality Recorder

In order to display the voltage waveform or harmonics for the monitored phase,
click on Scope or Harm buttons. The waveform or the harmonics table for the
monitored voltage phase will be displayed.

oltage 1

Real Time Mode

P V

Real Time Voltage

V1

Harm 1 0.00
Harm 3 0.00
Harm 5 0.00

Harm 7 0.00

Close

Back

How to Monitor Current Only?

From the Voltage and Current screen, click on the Current button. You will be
prompted to the current only real time display. The RMS value for the monitored
phase will be reported with its respective frequency.

Voltage & Current

V1: 116.13V __ l1: 3.96A

Click

Current

Back Voltage Current Power

In order to display the current waveform or the harmonics

Real Time (Current)

Ø1

Cur
(A) 0.00

Freq
(Hz) 0.00

Back Harm Scope

for the monitored

phase, click on Scope or Harm buttons. The waveform graph or the harmonics
table for the monitored Current phase will be displayed.

Real Time Mode

P Current 1

Real Time Harmonics

Ø1

1 0.00
3 0.00

0.00

5

7 0.00

Close

Back

11

DM-4 Power Quality Recorder

How to Monitor Power Only?

From the Voltage and Current screen menu, click on the Power button located at
the bottom of the screen.The Real Time Power screen will appear as shown
below with the following information: Real Power: P (kW); Reactive Power: Q
(kVAR); Apparent Power: S (kVA); True Power Factor: pF; and the displacement
power factor: dPf. To return to the previous screen, click on the Back button.

Real Time (Power)

Ø1 Ø2 Ø3 Total

P(kW) 0.00 0.00 0.00 0.00
Q(kVAR) 0.00 0.00 0.00 0.00

Click
Back

S(kVA) 0.00 0.00 0.00 0.00
PF 0.00 0.00 0.00 0.00
dPF 0.00 0.00 0.00 0.00

Back

3- Phase 4-wire, 60Hz System Using 1000A Clamp

• Once you have the DM-4 connected with your electrical system, you can follow
the same steps from paragraph 4.3 to paragraph 4.4.1.

• Select 3Ø4W, 60Hz, 1000A and then click OK.

Voltage & Current

V1: 0.000V _ _ l1: 0.00A
V2: 0.000V _ _ l2: 0.00A
V3: 0.000V __

Back Voltage Current Power

l3: 0.00A
ln: 0.00A

_

Click OK

to accept

the System

Setup

MDL-Main Menu

View Real Time Data
Setup a New Recording Session

R

TM Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:

P 60 Hz
P 1000 Amps

OK

• The Voltage and Current screen should display the readings for all three phases
as shown above.

• You can access the readings for voltage, current and power with their respective

waveforms and harmonics tables as described on “How to monitor voltage only?”,

“How to monitor current only?”, and “How to monitor power only?” in paragraph

4.4.1 for the 1Ø2W system.

12

DM-4 Power Quality Recorder

3-Phase 3-wire, 60HZ system with 1000A Clamp

Because the 3Ø3W system doesn’t have a neutral wire, you need to follow the
proper direction given in this manual to connect the DM-4 with the 3Ø3W
electrical system you want to monitor. Refer to paragraph 11.3

• Follow the same procedures as for 1Ø2W and 3Ø4W systems. The following
screen should appear when accepting the system configuration setup for 3Ø3W.

Voltage & Current

V1: 0.000V _ _ l1: 0.00A
V2: 0.000V _ _ l2: 0.00A
V3: 0.000V __ l3: 0.00A _

Back Voltage Current Power

ln: 0.00A

Click OK
to accept

the System

Setup

MDL-Main Menu

View Real Time Data
Setup a New Recording Session

R

TM Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:

P 60 Hz
P 1000 Amps

OK

4.4.2 Setup A New Recording Session

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

From the main menu, click on “Setup A New Recording Session”. The MDL
system Setup menu will be displayed.

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:
START:

P 60 Hz
P 1000 Amps

P Manual

ST

Back

OP:

P Manual

Next

13

DM-4 Power Quality Recorder

The MDL System setup allows you to configure the data logger device for the type
of power system you want to perform the recording.

• Phase Selection: 1Ø2W; 1Ø3W; 3Ø3W (Delta configuration); 3Ø4W (Wye configuration).

• Fund. Frequency: 50-Hz; 60-Hz

• Clamp Type: 100 Amps; 1000 Amps; 3000 Amps

• Integration Period: 5s, 15s, 30s, 1min, 5min, 15min, 30min, 1 hr

• Start: Manual or Automatic

- Manual: Recording session starts when you click on the “Record Now”

button in later screen

- Automatic: Recording session will start at the preset time.

• Stop: Manual or Automatic

- Manual: Recording session stops when you click on “stop recording”

- Automatic: Recording session stops at the preset time.

4.4.3 Set Date and Time For Automatic Recording Session

To set the date and time for an Automatic Recording session, follow the
steps below as shown on the screens on the previous page:

• Click on the drop down box of “START” and select “Set Time”

• Click on the drop down box of “Set Time” and select “Choose date”

• Select a date between the actual date of the year and 2031. (

NOTE: You cannot

choose a date in the past, for example 2001 is not a valid date).

• Repeat Step.2 to choose the time and click OK after a selection is made.

• Once you click on the RECORD button, the preset recording is stored in
memory. You can disconnect the Remote User Interface (PDA) at this point.

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:

T

Clamp
Integration Period:

:

T

AR

ST

OP:

ST

Back

P 60 Hz

ype:

P 1000
P 5 sec

ime

T

P Set

ue 3/15/05 3:08 pm

P T

ime

T

P Set

ue 3/15/05 3:08 pm

P T

Amps

Next

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:

T

Clamp
Integration Period:
START:

STOP:

Back

P 60 Hz

ype:

P Set Time

Now

P Tue 3/15/05 3:08 pm

Choose Date

Choose Date

P Set Time

Choose Time

P Tue 3/15/05 3:08m

P 1000
P 5 sec

Amps

14

Next

Recording Start Date

Q 2005 R

Jan Feb Mar Apr May Jun

Jul Aug Sep Oct Nov Dec

S M T W T F S

1 2 3 4 5

6 7 8 9 10 11 12
13 14
20 21 22 23 24 25 26
27 28 29 30 31

Cancel

(15)

Today

16 17 18 19

DM-4 Power Quality Recorder

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:

Type:

Clamp
Integration Period:
START:

STOP:

Back

P 60 Hz

Amps

P 1000
P 5 sec

P Set Time

Now

P Tue 3/15/05 3:08 pm

Choose Date

P Set Time

Choose Time

Choose Time

P Tue 3/15/05 3:08m

Next

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:
Integration Period:
START:

R

ecording Start Time

3 : 0 8 AM PM

OK

P Set Time

H
P

Cancel

P 60 Hz
P 1000 Amps
P 5 sec

5. MAIN MENU

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

5.1 INITIAL SETTINGS

Initial settings are the last settings the user configured the unit at the time of the
last use. Each time you access the device with the Remote User Interface (PDA) ,
you will be asked if you would like to retrieve the device existing settings. Click YES
to retrieve the existing settings and NO to reset the device with the Remote User
Interface (PDA) settings.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session

R

etrieve Settings?

Do you want to retreive
current settings from the
device?

No

Yes

15

DM-4 Power Quality Recorder

5.1.1 How to Set the Date and Time?

When connecting to the data logger, if the date and time of the device are different
from the Remote User Interface (PDA), the program will ask you if you would like
to synchronize the data logger with the Remote User Interface (PDA). Click on YES
to set the date and time manually or automatically. Click on NO to continue to use
the device. Important!!! (If you do not set the device time correctly, the auto-

matic recording will not take place.)

Connecting

If you are using serial port, make sure
that the device is connecting using
appropriate cable.

Wrong Settings

The data logger’s date and

v

time are not in sync with the
Palm. Do you want to
change the settings

No

Yes

Click Yes

to change

the settings

Set Time

Synchronize time with Palm’s clock

Y

Palm Time: 10/3/05 2:27pm

Set time manually

Set Date: 10/3/05
Set Time: 2:27pm

Click Done

to accept

the change

Done

Device Status

Record @ undefined

Device time 10/3/05 2:29 pm
Battery 100%
Memory 0%
F/W ver 1.0b3

Back

Set

NOTE. You can also use the Download Suite program to set the date and time in
the device.

5.2 DEFAULT SETTINGS: ANALYZER CONFIG

The basic setting allows you to quickly set the device for a recording session with
all the 456 parameters selected.

16

DM-4 Power Quality Recorder

5.2.1 How to Set the Type of Electrical System Under Test

• Phase Selection

This parameter permits you to select the type of electrical system under test among
the following configurations:

1Ø2W: Single phase system
1Ø3W: Single phase system
3Ø3W: 3 wires system (three-phase system without neutral)
3Ø4W: 4 wires system (three-phase system with neutral)

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:
Integration Period:

Comment: Recording 1
START: P Manual
STOP:

Back

P Manual

1Ø2W
1Ø3W

P 60 Hz

3Ø3W (Delta)

3Ø4W (Y)

Next

• Clamp Type
The value of this parameter must always be equal to the clamp type you are
using. Three types of clamps are available:

1000A: For Standard clamps of 1000 Amps
3000A: For Flexible clamps of 3000 Amps.
100A: For miniature clamps of 100 Amps.

Set the desired value by selecting the clamp type using the drop-down box.

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:

Clamp Type:

Integration Period:

START:
STOP:

Back

Comment:

P Manual
P Manual

17

P 60 Hz

100

1000 AMPS

3000 AMPS

AMPS

Next

DM-4 Power Quality Recorder

5.3 BASIC SETTING: RECORDER CONFIG

This option allows you to check and eventually modify the recording parameters
and the selected parameters (up to a maximum of 456).

5.3.1 MDL Parameter Setup

This option allows you to setup the parameters for a recording session. When using
the Remote User Interface (PDA) in basic setting, selecting any block will enable
all the parameters under this block.

MDL Parameter Setup

Y

RMS Voltage (all phases)

Y

RMS Current (all phases)

Y

Voltage Harmonics

Y

Current Harmonics
Voltage Frequency & Phase Shift

Y
Y

Current Frequency & Phase Shift
Power/Energy/PF(all phases)

Y

Demand

Y

Waveform

Y

Back

Next

To select/deselect a function block, just click on the checked box. The check mark
(√) indicates that the function block has been selected.

5.3.2 MDL Voltage Anomalies

This option allows you to setup the parameters for all the anomalies (Sag, Surge,
and Spike).

MDL Voltage Anomolies

Voltage Anomalies

Back

Next

To select the voltage anomalies function block, just click on the checked box.
A check mark (√) indicates that the function block is enabled.

18

DM-4 Power Quality Recorder

5.4 Advanced Setting: Recorder Configuration

The advanced setting option allows you to setup the desired parameters you want
for a recording session.
To enter the advanced setting mode:

1) From the MDL main menu screen, click on

MDL Main Menu and select Options

MDL-Main Menu

Click

MDL-Main

Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

2) From Options down drop list, choose MDL Preferences

Control Optons

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

Preferences

MDL
Beam MDL
About MDL

3) From MDL Preferences menu, select Advanced Mode by clicking on the

checked box. A check mark (√) indicates a selection. Press Ok to complete the
selection. You should return to the main menu.

MDL-Main Menu

View Real Time Data

MDL-Main Menu

MDL Preferencesu

Advance Mode:
Setup a New Recording Session

Comm Port:
Download Data

iew Downloaded Data

V

P Serial

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

19

DM-4 Power Quality Recorder

5.4.1 Setting the Parameters Individually
To set-up the parameters individually for a recording session, select “Setup a New
recording Session

” from the MDL Main Menu. The MDL System Setup will

appear. Click on Next to enter the MDL Parameter Setup screen.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:
Integration Period:

START: P Manual
STOP:

Back

P 60 Hz
P 1000 Amps
P 5 sec

Comment: Recording 1

P Manual

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage NA
Harmonics NA
Frequency NA
Phase Shift NA

Waveform

Back

Y

Y Y

A

A

A

Y

Y Y

Y

Y Y

Next

5.4.2 Advanced MDL Parameter Setup

The advanced MDL parameter setup option allows you to select one or all the
parameters for one or all the phases for Voltage, Current, and Power.

5.4.3 Set up the Parameters for Voltage
1Ø2W Single Phase 1Ø3W Single Phase

MDL Parameter Setup

Voltage Current Power

Variable Ø1

Voltage
Harmonics
Frequency
Phase Shift

Waveform

Back

A

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø12

Voltage
Harmonics
Frequency
Phase Shift

Waveform

Back

Y

Y Y

A

A

Y

Y

Y

Y

Next

3Ø3W Delta Configuration 3-phase 3Ø4W Wye Configuration 3-phase

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage NA
Harmonics NA
Frequency
Phase Shift NA

Y

Back

W

aveform

Y

Y Y

A

A

A

NA

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage NA
Harmonics NA
Frequency
Phase Shift NA

Y

Back

aveform

W

Y

A

20

Y Y

A

A

NA

Next

5.4.4 Setup the Parameters for Current
1Ø2W Single Phase 1Ø3W Single Phase

DM-4 Power Quality Recorder

MDL Parameter Setup

oltage Current Power

V

Variable Ø1

Current
Harmonics
Frequency
Phase Shift

Waveform

Back

A

Next

MDL Parameter Setup

oltage Current Power

V

Variable Ø1 Ø2

Current
Harmonics
Frequency
Phase Shift

W

Back

aveform

Y

Y

A

A

Y

Y

Y

Y

Next

3Ø3W Delta Configuration 3-phase 3Ø4W Wye Configuration 3-phase

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage
Harmonics
Frequency NA
Phase Shift NA

Y

Back

Waveform

Y

Y Y

A

A

A

Y
Y

A

Y Y
Y Y

Y

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage
Harmonics
Frequency NA
Phase Shift NA

Y

Waveform

Back

Y

Y Y

A

A

A

Y

Y Y

Y

Y Y

Y

A

Next

5.4.5 Setup the Parameters for Power

1Ø2W Single Phase 1Ø3W Single Phase

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 TOT

P (KWh)
Q (kVARh)
S(kVAh)
PF
dPF
PF true/displ

Back

Y
Y

Y
Y
Y
Y

Y
Y
Y
Y
Y
Y

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 TOT

P (KWh)
Q (kVARh)
S(kVAh)
PF
dPF
PF true/displ

Back

Y

Y
Y

Y
Y

Y

Y

Y

Y

Y

Y

Y

Y
Y
Y
Y
Y
Y

Next

21

DM-4 Power Quality Recorder

3Ø3W Delta Configuration 3-phase 3Ø4W Wye Configuration 3-phase

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2

P (KWh)
Q (kVARh)
S(kVAh)
PF
dPF
PF true/displ

Back

Ø3 TOT

Y

Y Y
Y

Y

Y

Y

Y Y

Y

Y Y

Y

Y Y

Y

Y Y

Y
Y
Y
Y
Y
Y

Next

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2

P (KWh)
Q (kVARh)
S(kVAh)
PF
dPF
PF true/displ

Back

Ø3 TOT

Y

Y Y
Y

Y

Y

Y

Y Y

Y

Y Y

Y

Y Y

Y

Y Y

Y
Y
Y
Y
Y
Y

Next

5.4.6 Setup the Parameters for Voltage Harmonics

To setup the parameters for voltage harmonics, you must be in the advanced
mode

when programming with the Remote User Interface (PDA).

1) From the main menu, select

start a new recording session. The MDL System

Setup screen appears. If you have already setup the device for the system you

want to monitor, click on NEXT and the MDL parameter setup screen should
appear. If you haven’t done so, refer to section 5.2.1

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

MDL System Setup

Phase Selection: P 3 Ø 4 W (Y)
Fund. Frequency:
Clamp Type:
Integration Period:

START: P Manual
STOP:

Back

P 60 Hz
P 1000 Amps
P 5 sec

Comment: Recording 1

P Manual

Next

22

DM-4 Power Quality Recorder

2) From the MDL parameter setup screen, select voltage and choose “A”

(harmonic) under the phase you want to monitor. You need to setup each phase
separately when monitoring more than one phase.

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage NA
Harmonics NA
Frequency NA
Phase Shift NA

Waveform

Back

Y

Y Y

A

A

A

Y

Y Y

Y

Y Y

Y

Y Y

Next

Harmonics Phase-1

Harmonics Phase-2

Harmonics Phase-3

3) From the Harmonics setup screen, you can select the harmonics you want to

enable by clicking on the numbers. To unselect a number, just click on it another
time. Click on

done to confirm the selections.

Recording Start Date

Harmonics

1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51

Select All

Clear All

Done

Recording Start Date

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51

Select All

Harmonics

Clear All

Harmonics #’s

1, 3, 7, 15 and

49 are selected

Done

5.4.7 Setup the Parameters for Current Harmonics

To setup the parameters for current harmonics, repeat step 5.4.5 and select
Current in step.2

MDL Parameter Setup

Voltage Current Power

Variable Ø1 Ø2 Ø3 N

Voltage
Harmonics
Frequency NA
Phase Shift

Back

Waveform

Y

A

Y
Y

Y Y

A

Y Y
Y Y

Y

A

A

NA

Next

23

DM-4 Power Quality Recorder

5.5 Download Data

After a recording session, you can retrieve your data by downloading the file from
the device to your PC, using the Download Suite, or from the device to your
Remote User Interface (PDA).

5.5.1 Download Data with the Remote User Interface (PDA)

To retrieve a file from the device with your Remote User Interface (PDA), click on
Download Data from the MDL main menu. On the

Remote Recordings screen,

select the file you want to download and click on Download. Once Downloading
recording is complete, you will be redirected back to the Remote Recordings
screen. If you don’t have any more recording files to download, click on the back
button to return to the main menu.

Click

Download

Data

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

Remote Recordings

1/1/70 12:46 am

Downloading Recording...

Remote Recordings

1/1/70 12:46 am

Back

Mobile Datalogger

45%

Cancel

24

Delete

Download

Click

Download

DM-4 Power Quality Recorder

5.5.2 View Downloaded Data

This option allows you to view all downloaded files in the Remote User Interface
(PDA). Once a file is downloaded, you can select it to be viewed. To view a down­loaded file, click on

View Downloaded Data from the MDL main menu. The pro-

gram will prompt you to the Saved Recordings screen. Select the file you want to
view by clicking on it once.

Saved Recordings

Recordings Date Time

2760 1/1/70 12:46am
1111069687 3/17/05 2:28pm

Click

Click View

Downloaded

Data

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Recorded

Delete Session Device Status

From This screen,
you can select the

recorded information

you want to view by
clicking on any item

on the list.

Back

Recording Parameters

Recording Information

- V Voltage RMS

- V Harmonics

- V Frequency

- V Phase Shift

- Voltage Anomalities (Spikes)

- Power (P,Q,S,PF,dPF)

- Energy (Ep, Eq, Es)

- Demand

Back

- I Current RMS

- I Harmonics

- I Frequency

- I Phase Shift

Next

Data

5.5.3 Recording Information

The recording information dialog box allows you to view the settings that have been
used in this recording session. Click on “OK” to return to the recording

parameters

screen.

Recording Information

Fund Freq: 60
System: 3
Int. Period: 5
Clamp: 1000
Start: 3/17/05 2:28pm
Stop: 3/17/05 3:12pm
Comment:

Monday031405

Click OK

25

OK

DM-4 Power Quality Recorder

5.5.4 Delete Session

To delete a recording session from the device, choose Delete Session from the
main menu. The device will prompt you to the remote recording files. From the
remote recording files screen, select a file or the files you want to delete and then
click on Delete.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Remote Recordings

4/20/05 2:00pm

4/25/05 10:55 am
4/25/05 1:45 pm
4/25/05 1:45 pm

Select the

recording

session you

want to delete

and click on

Delete Session Device Status

Back

Delete

Download

Delete

Symbols Description Advised Settings

START:MAN The recording of all the selected parameters will start at

00 seconds after pressing RECORD

STOP:MAN The recording of all the selected parameters will be

interrupted manually by pressing RECORD.

START:AUTO
STOP:AUTO

The recording of all the selected values will be started /
interrupted at the set dates and times. In order to start

☺☺
☺☺

the recording the user will have to select RECORD to
set the instrument in Stand-by mode until the start date
and time previously set.

INT. PERIOD The value of this parameter determines how many sec-

onds the values of all the selected parameters will be

15min

stored. Available choices:
5sec, 15sec, 30sec, 1min, 5min, 15min, 30min, 1hr.

☺☺

HARM REC. Enable = the instrument will record the values of the

selected voltage and current harmonics
corresponding to the voltages and currents selected in
the corresponding pages “Voltage” and “Current”.

Example: If the following Parameters are selected:

a) Phase Voltage 1 and 2, Thd, Harmonics 1, 3, 5.
b) Phase Current 2 and 3, Thd, Harmonics 3, 5, 7.

The instrument will record:

a) The Phase Voltage 1 and 2, Thd and Harmonics 1,3,5 of the Phase
Voltage 1 and 2 while it will not record anything about Phase Voltage 3
b) The Phase Current 2 and 3, Thd and Harmonics 3,5,7 of the Phase
Current 2 and 3 while it will not record nothing about Phase Current 1

☺☺

Disable = the instrument will not record any voltage or
current harmonic selected

26

DM-4 Power Quality Recorder

Symbols Description Advised Settings

ANOM REC. Enable = the Instrument will record Voltage Sag, Surge,

and voltage spike
Disable = the instrument will not record any voltage

Sag, Surge, and voltage spike.

V1, V2, V3
V12, V23 or
V32, V31

Thd, DC, 01...51 Voltage Total Harmonic Distortion, DC Component,

Vref (Only if
ANOM. REC flag
has been enable)

LIM+, LIM­(Only if ANOM.
REC flag has
been set ON)

I1, I2, I3, IN RMS value of the current of phase 1, phase 2, phase 3

Thd, DC, 01..51 Current Total Harmonic Distortion, DC Component,

Pt, P1, P2, P3,
P12, P32, P31

RMS value of the voltage of phase 1, phase 2, phase 3
respectively, values of the phase-to-phase voltages 1-2,
2-3 or 3-2 and 3-1.

01..51 Harmonics respectively

RMS reference value for Voltage used in Voltage
Anomalies detection (Voltage Sag and Surge).
The Reference is:
a) Voltage Phase to Neutral for Single Phase and 4
wires three phase system
b) Voltage Phase to Phase for 3 wires three phase system

High and Low Voltage Percent threshold used in
Voltage Anomalies detection (Voltage Sag and Surge).

Example: Three Phase System 4 wires.
Vref = 120, LIM+= 10%, LIM-=10% =>
High Lim = 132V, Low Lim = 108.0V

The Instrument will detect a voltage Anomalies if the
RMS Voltage Values (calculated every 14ms) beyond
the above calculated thresholds

and of the neutral respectively.

01..51 Harmonics respectively
Values of the active power (total, of phase 1, phase 2

and phase 3) (only for 3 wires measurement)
value of the power measured by the W
3-2 respectively.

attmeter 1-2 and

3 wires V12V32V

4 wires V1, V2, V

Thd,01,03,05,07

4 wires Pt, P1, P2, P3

☺☺

☺☺

Single phase: V1

3

☺☺

Thd,01,03,05,07

☺☺

Single phase: 230V

3 wires: 400V
4 wires: 230V

☺☺

Single phase: 120V

3 wires: 480V

4 wires 277V

☺☺

Single phase: I1

3 wires: I1, I2, I3

4 wires I1, I2, I3, IN

☺☺

Single phase: P1

3 wires: Pt

31

27

DM-4 Power Quality Recorder

Symbols Description Advised Settings

Qt, Q1, Q2, Q3,
Q12, Q32, Q31

-Qt, -Q1, -Q2, -Q3,

-Q12, -Q32, -Q31

St, S1, S2, S3,
S12, S32, S31

Values of the inductive reactive power (total, of phase 1,
phase 2, phase 3) (only for 3 wires measurement) value
of the reactive inductive power measured by the VAR
meters 1-2 and 3-2 respectively

Values of the capacitive reactive power (total, of phase
1, phase 2, phase 3) (only for 3 wires measurement)
value of the reactive capacitive power measured by the
VA meters 1-2 and 3-2 respectively

Values of the apparent power (total, of phase 1, phase 2,
phase 3) (only for 3 wires measurement) value of the power
measured by the VAmeters 1-2 and 3-2 respectively

☺☺

Single phase: Q1

3 wires: Qt

4 wires Qt, Q1, Q2, Q3

☺☺

Single phase: S1

3 wires: St

4 wires St, S1, S2, S3

Pft, Pf1, Pf2, Pf3 Values of the power factors (total, of phase 1, phase 2

and phase 3 respectively)

dpft, dpf1, dpf2,
dpf3

Eat, Ea1, Ea2,
Ea3

Ert, Er1, Er2, Er3 Values of the inductive reactive energy (total, of phase

-Ert, -Er1, -Er2, ­Er3

Est, Es1, Es2, Es3 Values of the Apparent Energy (total, of phase 1,

Selecting a power factor (Pf) or a cosΘ (dPf) for the recording automatically their inductive value
and their capacitive value will be recorded separately.

Values of the cosΘ (total, of phase 1, phase 2 and
phase 3 respectively)

Values of the active energy (total, of phase 1, phase 2,
phase 3)

1, phase 2 and phase 3)

Values of the capacitive reactive energy (total, of phase
1, phase 2, phase 3)

phase 2, phase 3)

Single phase: Pf1 dPf1

☺☺

3 wires: Pft dPft

4 wires Pft Pf1 Pf2

Pf3dPft dPf1 dPf2

dPf3

☺☺

Single phase: Ea1

3 wires: Eat

4 wires Eat Ea1 Ea2

Ea3

☺☺

Single phase: Er1

3 wires: Ert

4 wires Ert Er1 Er2

Er3

☺☺

Single phase: Es1

3 wires: Est

4 wires Est

Es3

Es1

Es2

28

DM-4 Power Quality Recorder

5.5.5 RESET (PRESS AND HOLD RESET KEY WHILE PRESSING ON RECORD)

This option re-establishes the default settings of the instrument.

The default settings of the instrument consist of:

ANALYZER CONFIG:

Frequency: 60Hz
Full scale of the clamps: 1000A
Type of electrical system: 4 wires

RECORDER CONFIG:

Start: Manual (the recording is started at 00 sec mark on clock after pressing the RECORD key)
Stop: Manual
Integration period: 5S
Recording of harmonics: ON
Recording of Sag and Surge: OFF
Voltage Reference for Sag and Surge detection: 480V
Upper Limit for Sag and Surge detection: 10%
Lower Limit for Sag and Surge detection: 10%
Selected voltages: V1, V2, V3
Selected voltage harmonics:
Selected currents: I1, I2, I3, IN
Selected current harmonics:
Powers, Pf and cosΘΘselected:

Pt, P1, P2, P3
Qt, Q1, Q2, Q3
Qt, Q1, Q2, Q3
St, S1, S2, S3
Pft, Pf1, Pf2, Pf3
dpft, dpf1, dpf2, dpf3

Energies:

Eat, Ea1, Ea2, Ea3
Erit, Eri1, Eri2, Eri3
Erct, Erc1, Erc2, Erc3
Est, Es1, Es2, Es3

Note: The RESET command will not erase the instrument’s memory.

29

DM-4 Power Quality Recorder

6. RECORDING CONFIGURATION

More practically, we may schematize the right procedure of use as follows:

1) Connect the External Power Supply

2) Check and eventually modify the basic settings of the instrument.

3) Select the parameters to be recorded.

4) Connect the DM-4 to the electrical system to be tested and push the
ON/OFF button

5) Evaluate the values of the parameters under test

6) If you want to record:

A) Decide what to record
B) Select MDL Setup Parameter and check if the existing parameters meet

your requirements

7) Start the recording by pressing RECORD.

7. STARTING A RECORDING

You can start a recording manually or automatically. Therefore, after setting all the
parameters and click on RECORD, the instrument will start recording:

MANUALLY: The recording will start when Instrument’s time reaches the “00” sec­onds value after pressing RECORD.

AUTOMATICALLY: If the operator has clicked on RECORD the instrument will
remain in stand-by until the date and time previously set, then the recording will start.

If the operator has not clicked on RECORD, the recording will never start.

m

For recordings ALWAYS use the external power supply even though the
instrument allows the operator to perform a recording using internal batteries.

CAUTION

30

DM-4 Power Quality Recorder

If during a recording the external power supply is de-energized, the instrument will
continue the recording using the internal battery power until the batteries are
exhausted (the data stored until the definitive turning off won’t get lost). For this
reason we recommend that you

ALWAYS insert a new set of batteries before a

long recording.

• If the instrument is recording or is measuring energy (and the external
power supply is not connected), the recording will continue until the batteries
are exhausted.

Before starting a recording the operator should first evaluate the state of the
equipment, decide what to record and set the instrument accordingly.

In order to facilitate this task the instrument has been factory pre-set with a
general configuration which should fit most cases. Using the RESET option
(See paragraph 5.6).

By pressing

RECORD the recording of the selected parameters is started

according to the settings made in the MENU (see paragraphs 5.2 and 5.3).

As the default value of the integration periods is set at 5 seconds the instrument will
store data in the temporary memory every 5 seconds. Afterwards the instrument will
explain the results saved in the temporary memory and will save the first series of
values in the permanent memory. Therefore, if an integration period of 5 seconds has
been set, the recording will continue for about 5 seconds before producing a set of
recorded values. If the recording is interrupted before the selected integration period
has completely elapsed, the data stored in the temporary memory (SRAM) will not be
elaborated and the corresponding series of values won’t be transferred to the
permanent memory (FLASH).

31

DM-4 Power Quality Recorder

8. RECORDING IN PROCESS

If during a recording the external power supply is de-energized, the instrument will
continue the recording using the internal battery power until the batteries are
exhausted (the data stored up to the point the instrument shuts down won’t get
lost). For this we recommend you
a long recording. You may not be able to download this file with the Remote User
Interface (PDA) device. We recommend that you use the Download Suite to open
this file.

During a recording the following commands are disabled:

• AUTOPOWER OFF function

• ON/OFF key

• RESET key

Click “DEVICE STATUS” on the main menu and the following screen will appear:

ALWAYS insert a new set of batteries before

This page includes:

1) Recording information

2) Device Date and Time

3) Battery condition

4) Memory size available

5) Firmware version

Device Status

Recording @ 0 (undefined)
Device Time 1/1/70 12:06 am
Battery 100%
Memory 99%
F/W ver 1.2

Back

32

Set

DM-4 Power Quality Recorder

9. STOPPING A RECORDING

The instrument uses a protective routine to avoid the risk of being disturbed or
interrupted during a recording or an energy measurement. Once a recording has
been started using automatic record mode, it won’t be sufficient to press the
RECORD key on the device to stop the recording. You need to use the Remote
User Interface (PDA) or the download suite to stop the recording.

9.1 Stop a Recording with the REMOTE USER INTERFACE (PDA)

To stop a recording with the Remote User Interface (PDA) , click on the MDL Main
Menu screen and then select STOP RECORDING.

MDL-Main Menu

View Real Time Data
Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

Control Optons

Start Recording

View Real Time Data

Stop Recording

Setup a New Recording Session
Download Data
View Downloaded Data

Delete Session Device Status

9.2 Stop a Recording with the Download Suite

To stop a recording with the download suite, go to control panel screen window and
then click on stop recording.

33

DM-4 Power Quality Recorder

10. CONNECTING THE INSTRUMENT TO A PC

In order to connect the instrument to a PC you must connect the serial cable
shipped with the instrument to the serial output of the PC.

The DM-IV serial cable has the following inner connections:

2
Male connector 9 pins 3
on the instrument side 5

2
3 Female connector 9 pins
5 on the PC side

The available transmission speeds are the following:
4800, 9600, 19200, 57600(default value)

The value of the transmission speed (Baud Rate) must be selected on the Remote User
Interface (PDA) or the Download Suite in order to have proper communication. The down­load suite will always look for COM1 first if the setting is set to

AUTOMATICALLY.

For download suite instructions please refer to software help file.

In order to transfer the recorded data from the instrument to the PC the following
procedure must be followed:

1) Switch ON the instrument

2) Connect the serial output of the instrument to the serial output of the
PC through the serial cable

34

DM-4 Power Quality Recorder

3) Install the software and start it – Close the introduction window

4) Press F2 and follow the commands.

5) Refer to software help file for further instructions.

11. MEASURING PROCEDURES

11.1 USING THE INSTRUMENT IN A SINGLE PHASE SYSTEM

CAUTION

The maximum voltage between L1 and COM inputs is CATIII 635V~

m

phase-phase and 370V~ phase – earth. Do not measure voltages
exceeding the limits prescribed by this manual. Should you exceed the
voltage limits you could damage the instrument and/or its components
or endanger your safety.

Phase 1

Phase 2

Neutral

Phase 3

Black

Yellow

Instrument connection in a single-phase system

CAUTION

m

1) Check the cables connection.

2) Connect the phase and neutral voltage wires according to the connections
shown in the above picture.

If possible, before connecting the instrument to the electrical system,
remove the power off the electrical system.

35

DM-4 Power Quality Recorder

3) Turn ON the unit by pressing the ON/OFF push button

4) If you want to measure current and power, connect the clamp meter to the phase

conductor respecting the specifications shown on the clamp and the connections

shown in the picture.

5) Apply voltage to the electrical equipment under test (if previously shut off for the
instrument connection).

6)The values of the available electrical parameters will be displayed on the Remote

User Interface (PDA) display or the PC screen. For further details see the Remote

User Interface (PDA) settings.

7) If you want to record, simply press the RECORD push button on the device.

11.2 USING THE INSTRUMENT IN A THREE PHASE 4- WIRE SYSTEM (WYE)

CAUTION

The maximum voltage between L1, L2, L3 & COM inputs is CAT III 635

m

V~ phase – phase 370 V~ phase to earth. Do not measure voltages
exceeding the limits prescribed by this manual. Should you exceed the
voltage limits you could damage the instrument and/or its components
or endanger your safety.

Phase 1

Phase 2

Neautral

Phase 3

Black

Red

Yellow

Blue

Instrument connection in a three-phase 4 wire system

36

DM-4 Power Quality Recorder

CAUTION

m

1) Check the cables connection.

2) Connect the phase and neutral voltage wires respecting the connections shown
in the picture.

3) If you want to measure current and power, connect the clamp meter to the phase

conductor respecting the specifications shown on the clamp and the connections
shown in the picture. In case of doubts select the position
connecting one clamp at a time, check if:
a) The phase sequence is correct
b) The active power P of each phase is positive.

c) The value of the Pf of each phase is not excessively low (typically it’s not lower

4) Apply voltage to the electrical equipment under test (if previously shut off for the
instrument connection).

5) The values of the available electrical parameters will be displayed.

6) If you want to record:

a) Check and, if needed, modify the values of the basic parameters (see

b) Check and, if needed, modify the recording parameters.
c) To start the recording press

If possible, before connecting the instrument to the electrical equipment
to be tested take the power supply off the electrical equipment.

POWER and,

than 0.4). In case the Pf is lower than 0.4, check if the phase voltage is
associated to the right clamp meter (for example the voltage of phase 1 must
be associated to the clamp meter no. 1).

paragraphs 5.2 and 5.3).

RECORD.

37

DM-4 Power Quality Recorder

11.3 USING THE INSTRUMENT IN A THREE PHASE 3- WIRE SYSTEM (DELTA)

CAUTION

m

The maximum voltage between V1, V2, V3 and COM (L2) inputs is
CATIII 600V~ phase-phase. Do not measure voltages exceeding the
limits prescribed by this manual. Should you exceed the voltage limits
you could damage the instrument and/or its components or endanger
your safety.

m

m

Phase 1

Phase 2

Phase 3

Instrument connection in a 3 wires three-phase system (DELTA)

Black

Red

Blue

CAUTION

Please note that in this case the yellow cable (neutral) is connected with
the red cable on phase 2. You can use any phase you want as reference.

CAUTION

If possible, before connecting the instrument to the electrical equipment
to be tested take the power supply off the electrical equipment.

38

DM-4 Power Quality Recorder

1) Check, and if needed modify, the basic settings of the instrument (see
paragraphs 5.2 and 5.3). Particularly, the 3 wires mode must be set.

2) Connect the phase and neutral voltage wires respecting the connections shown
in the picture.

3) If you want to measure current and power, connect the clamp meter to the phase

conductor respecting the specifications shown on the clamp and the connections
shown in the picture. Check if:

a) The phase sequence is correct
b) The active power P of each phase is positive.

c) The value of the Pf of each phase is not excessively low (typically it’s not lower

than 0.4). In case the Pf is lower than 0.4, check if the phase voltage is

associated to the right clamp meter (for example the voltage of phase 1 must

be associated to the clamp meter no. 1).

d) After checking, and if needed modifying, the connection of the instrument to

the equipment re-set the

3 wires mode and the connections shown in the

picture (yellow and red wire together).

4) Apply voltage to the electrical equipment under test (if previously shut off for the
instrument connection).

5) The values of the available electrical parameters will be displayed of the instrument.

6) If you want to record:
a) Check and eventually modify the values of the basic parameters (see

paragraphs 5.2-5.3).

b) Check and eventually modify the recording parameters (see How to set the

parameters using Remote User Interface (PDA).

c) To start the recording press

RECORD

39

DM-4 Power Quality Recorder

12. MAINTENANCE

12.1 GENERAL

The DM-4 is a precision instrument. For its’ use and storage, follow the recommendations
and instructions contained in this manual in order to avoid possible damages. Never use
the instrument in environments with a high humidity or temperature. Always turn off the
instrument if it is not in use.

12.2 BATTERY REPLACEMENT

When the battery indicator indicates less than 50% ( q ), the batteries must
be replaced.

CAUTION

Only qualified technicians should operate the instrument. Before

m

1) Disconnect cables and clamps from the circuit under test.

2) Turn the instrument off by pressing ON/OFF push button.

3) Remove the cables from the input terminals.

4) Unscrew the screw of the battery cover and remove the cover.

5) Replace the batteries with 8 new 1.5 V - AA.

6) Reposition the cover and fasten it with the proper screw.

replacing the batteries, disconnect the test leads from circuit under
voltage in order to avoid electrical shocks.

(Alkaline LR6 is strongly recommended.)

12.3 CLEANING

Use a soft dry cloth to clean the instrument. Do not use wet clothes, solvents,
water and so on.

40

DM-4 Power Quality Recorder

13. TECHNICAL SPECIFICATIONS

13.1 FEATURES

The accuracy is stated as [1% of the reading ± number of 2 digits]. It refers to the
following atmospheric conditions: temperature 73°F± 2°F (23°C ± 1°C) with rela­tive humidity < 75%.

13.1.1 Voltage Measurement

Range Accuracy Resolution Input Impedance

20-370V ±(3%+2digit) 0.1V 300kΩ (phase-neutral)

310-635V 0.1V 600kΩ (phase-phase)

13.1.2 Voltage Anomalies Detection (Manual Selection of Range) Voltage

Range Accuracy Resolution Input Impedance

20-370V ±(3%+2digit) 0.1V 300kΩ (phase-neutral)

310-635V 0.1V 600kΩ (phase-phase)

Time

Accuracy (ref. to 60Hz) Resolution

±8.33ms (1/2 period of fundamental) 8.33ms (1/2 period of fundamental)

13.1.3 Current Measurement (Using external transducer)

Range Accuracy Resolution Input

Impedance

Protection against

overloads

0.005-0.26V ±(2%+2digit) 100kΩ 5V

0.26-1V

Minimal Current measurable is equal to 0.5% of Clamp Full Scale

41

13.1.4 Power Measurement (cosΘΘ: 0.5c – 0.5i)

Value Ranges Accuracy Resolution

0 – 999.9W

Active Power

1KW – 999.9KW

1MW – 999.9MW

0 – 999.9VAR

Reactive Power

1KVAR – 999.9KVAR

1MVAR – 999.9MVAR

0 – 999.9VA

Apparent Power

1KVA – 999.9KVA

±(3%+2digit)

1MVA – 999.9MVA

0 – 999.9Wh

Active Energy

1KWh – 999.9KWh

1MWh – 999.9MWh

0 – 999.9VARh

Reactive Energy

1KVARh – 999.9KVARh

1MVARh–999.9MVARh

DM-4 Power Quality Recorder

13.1.5 CosΘΘMeasurement

CosΘ Resolution Accuracy (expressed

0.20

0.50 4˚

0.80 5˚

in degrees)

3˚

0.01

42

13.1.6 Measurement of Harmonics

Voltage

Range Accuracy Resolution

DC – 25h
26h – 33h
34h – 51h

The voltage harmonics will be null under the following threshold:

- DC: if <1V or <2% of 1stharmonic

- 1stharmonic: if <2V

- 2nd- 51st: if <1V or <2% 1stharmonic

±(5.0%+2digit)
±(10.0%+2digit)
±(15.0%+2digit)

Current

Range Accuracy Resolution

DC – 25h
26h – 33h
34h – 51h

The voltage harmonics will be null under the following threshold:

- DC: if <2% of 1stharmonic or < 0,2% of clamp full scale

- 1stharmonic: if < 0,2% of clamp full scale

- 2nd- 51st: if<2% 1stharmonic or < 0,2% of clamp full scale
Setting the FLEX option 3000A CT the DC component will be ignored.

±(5.0%+2digit)
±(10.0%+2digit)
±(15.0%+2digit)

DM-4 Power Quality Recorder

0.1V

0.1A

13.1.7 Temperature Drift
Temperature drift: 0.1 x accuracy/K

13.1.8 Safety
Insulation: Class 2
Pollution: 2
Over-voltage category: CAT III 600V~ (Phase-phase)

CAT II 1000V~ (Phase-Phase)

43

DM-4 Power Quality Recorder

13.1.9 General Characteristics

Mechanical Features

Dimensions: 8.9” (L) x 4.1” (La) x 2.1” (H)

225(L) x 104(La) x 54(H) mm

Weight: 3.3 Lb (1.5kg)
Internal Power Supply: 8 batteries 1.5V series AA
Battery Life: 3-hours
External Power Supply: Use only Amprobe power supply Adapter code DM4EXTPS
Display: LED
Sampling Speed: 83.33 usec at 60Hz.
No. of Samples Per Period: 128

Clamp

Opening: 2.15” (53 mm)
Maximum Diameter of The Cable: 2.00” (50 mm)

13.2 ENVIRONMENT

13.2.1 Operating conditions

Reference Temperature:

73°F ± 2°F (23°C ± 1°C)

Operating Temperature: 32°F to 122°F (0°C to 50 °C)
Relative Humidity: <70%
Storage Temperature: 14°F to 140°F (-10°C to 60 °C)
Storage Humidity: <80%

44

13.3 ACCESSORIES

13.3.1 Standard Accessories

The package contains:

Replacement Parts Part Number

DM-4 Power Quality Recorder

Remote user interface (PDA) with
connection cable

Instrument
Carrying case
External power supply 12VDC
1000A Clamp
Test Leads & Alligator Clips
(Set of 4)
PDA/DM-4 Interface Cable

RS-232 Computer Cable
Remote User Interface
Protective Case

RS-232 To USB Converter Cable
1 User Manual

Download Suite
Palm OS software

Recommended Tungsten E2 Ordered
through PALM retailers, visit www.palm.com

DM-4
HW1254A
DM-4EXTPS
DM-CT-BKCE
DVL-2

RS-PDA
C232NG1

DM-4CASE

RS-USB

www.amprobe.com
www.amprobe.com
www.amprobe.com

45

DM-4 Power Quality Recorder

14. APPENDIX 1 – RECORDABLE PARAMETERS: SYMBOLS

Symbol Description

V1, V2, V3 RMS value of the voltage of phase 1, phase 2, phase 3 respectively
V12, V23 V31 Value of phase to phase voltages
I1, I2, I3 RMS value of the current of phase 1, phase 2, phase 3 respectively

IN RMS value of the current of the neutral
DC Continuous component of voltage or current

h01 ∏ h51 Harmonic 01 ∏ Harmonic 51 of voltage or current
ThdV Factor of total harmonic distortion of the voltage (see paragraph 14.2)
ThdI Factor of total harmonic distortion of the current (see paragraph 14.2)
Pt, P1, P2, P3 Values of the total active power, of phase 1, phase 2, phase 3 respectively
P12, P32, P13 (only for 3 wires measurement) Value of the power measured by the

Wattmeter. 1-2 and 3-2 respectively (see paragraph 14.3.2)
Qt, Q1, Q2, Q3 Values of the total reactive power, of phase 1, phase 2, phase 3 respectively
Q12, Q32, Q13 (only for 3 wires measurement) Value of the power measured by the

VARmeter 1-2 and 3-2 respectively (see paragraph 14.3.2)
St, S1, S2, S3 Values of the total apparent power, of phase 1, phase 2, phase 3 respectively
S12, S32, S13 (only for 3 wires measurement) Value of the power measured by the

VAmeter 1-2 and 3-2 respectively (see paragraph 14.3.2)
Pft, pf1, pf2, pf3 Value of the total power factors, power factors of phase 1, phase 2, phase 3

respectively
dPft, dpf1, dpf2, dpf3 Values of the total cosΘ, of phase 1, phase 2, phase 3 respectively

Eat, Ea1, Ea2, Ea3 Values of the total active energy, of phase 1, phase 2, phase 3 respectively
Ert, Er1, Er2, Er3 Values of the total inductive reactive Energy, of phase 1, phase 2, phase 3

respectively

-Ert, -Er1, -Er2, -Er3 Values of the total capacitive reactive Energy, of phase 1, phase 2, phase

3 respectively
Est, Es1, Es2, Es3 Values of the total

Apparent Energy, of phase 1, phase 2, phase 3 respectively

Negative Q (reactive power) indicates capacitive phase shift. Negative P
cates generation not load and the CTs should be reversed, rotated 180º.

46

(real or active power) indi

-

DM-4 Power Quality Recorder

15. APPENDIX 2 – THEORETICAL OUTLINES

15.1 VOLTAGE ANOMALIES (VOLTAGE SAG AND SURGE; SPIKE)

The instrument records as voltage anomalies all those rms values, calculated every
11ms, beyond the percent thresholds of Voltage Reference (Vref) set during the pro­gramming. The maximum upper limit percent is reduced as Vref approaches 1000V.

THE REFERENCE MUST BE SET TO

Nominal Voltage Phase to Neutral: for Single Phase and 4 wires three phase system
Nominal Voltage Phase to Phase: for 3 wires three phase system

Example1: Three Phase System 3 wires

Vref = 400V, LIM+= 10%, LIM-=10% =>
High Lim = 480 x (1+10/100) = 528V
Low Lim = 480 x (1-10/100) = 452V

Example2: Three Phase System 4 wires

Vref = 277V, LIM+= 5%, LIM-=5% =>
High Lim = 277 x (1+5/100) = 290.85V
Low Lim = 277 x (1-5/100) = 263.15V

The Instrument will detect Voltage Anomalies if the RMS Voltage Values (calculat­ed every 11ms) beyond the above calculated thresholds. These limits remain
unchanged throughout the recording period.

When a Voltage Anomaly Occurs the Instrument Records:

• The number corresponding to the phase where the anomaly occurred.

• The “direction” of the anomaly: “UP” and “DN” identify respectively voltage drops
(sag) and peaks (Surge).

• The date and time of the beginning of the event in the form day, month, year, hour,
minutes, seconds, hundredths of second.

• The duration of the event, in seconds with a resolution of 11ms.

• The minimum (or maximum) value of voltage during the event.

47

DM-4 Power Quality Recorder

15.2 VOLTAGE AND CURRENT HARMONICS

15.2.1 THEORY

Any periodical non-sine wave can be represented as a sum of sinusoidal waves
having each a frequency that corresponds to an entire multiple of the fundamental,
according to the relation:

v(t) = V0+ ∑ Vk sin (wk t + Øk ) (1)

∞

k=1

Where:
V0 = Average value of v (t)

V1 = Amplitude of the fundamental of v (t)
Vk = Amplitude of the kthharmonic of v (t)

LEGEND:

1. Fundamental

2. Third Harmonic

3. Distorted Waveform

Effect of the sum of 2 multiple frequencies.

In the main voltage, the fundamental has a frequency of 60 Hz, the second harmonic
has a frequency of 120 Hz, the third harmonic has a frequency of 180 Hz and so on.
Harmonic distortion is a constant problem and should not be confused with short
events such as sags, surges or fluctuations. It can be noted that in (1) the index of the
sigma is from 1 to the infinite. What happens in reality is that a signal does not have
an unlimited number of harmonics: a number always exists after which the harmonics
value is negligible. The EN 50160 standard recommends to stop the index in the

th

expression (1) in correspondence of the 40

harmonic.

48

DM-4 Power Quality Recorder

A fundamental element to detect the presence of harmonics is Thd defined as:

This index takes all the harmonics into account. The higher it is, the more
distorted the waveform gets.

15.2.2 Limit Values for Harmonics

EN-50160 fixes the limits for the harmonic voltages, which can be introduced into
the network by the power supplier. In normal conditions, during whatever period of
a week, 95% if the RMS value of each harmonic voltage, mediated on 10 minutes,
will have to be less than or equal to the values stated in the following table. The
total harmonic distortion (Thd) of the supply voltage (including all the harmonics up
to 40th order) must be less than or equal to 8%.

Odd Harmonics Even Harmonics

Not multiple of 3 Multiple of 3 Order h Relative voltage

Order h Relative voltage

% Max

5 6 3 5 2 2

7 5 9 1,5 4 1
11 3,5 15 0,5 6.24 0,5
13 3 21 0,5

17 2
19 1,5
23 1,5
25 1,5

Order h Relative voltage

% Max

% Max

These limits, theoretically applicable only for the supplier of electric energy, provide
however a series of reference values within which the harmonics introduced into
the network by the users must be contained.

49

DM-4 Power Quality Recorder

15.2.3 Presence of Harmonics: Causes

Any apparatus that alters the sine wave or uses only a part of such a wave caus­es distortions to the sine wave and therefore harmonics. All current signals are in
some way distorted. The most common situation is the harmonic distortion caused
by non-linear loads such as household appliances, personal computers or speed
control units for motors. Harmonic distortion causes significant currents at frequen­cies that are odd multiples of the fundamental frequency. Harmonic currents affect
considerably the neutral wire of electric installations. In most countries, the main
power is three-phase 50/60Hz with delta primary and star secondary transformers.
The secondary generally provides 230V AC from phase to neutral and 400V AC
from phase to phase. Balancing the loads on each phase has always represented
a headache for electric systems designers. Until some ten years ago, in a well-bal­anced system, the vectorial sum of the currents in the neutral was zero or quite low
(given the difficulty of obtaining a perfect balance). The devices were incandescent
lights, small motors and other devices that presented linear loads. The result was
an essentially sinusoidal current in each phase and a low current on the neutral at
a frequency of 50/60Hz. “Modern” devices such as TV sets, fluorescent lights,
video machines and microwave ovens normally draw current for only a fraction of
each cycle thus causing non-linear loads and subsequent non-linear currents. All
this generates odd harmonics of the 50/60Hz line frequency. For this reason, the
current in the transformers of the distribution boxes contains only a 50Hz (or 60Hz)
component but also a 150Hz (or 180Hz) component, a 300Hz (or 360Hz) compo­nent and other significant components of harmonic up to 750Hz (or 900Hz) and
higher. The vectorial sum of the currents in a well-balanced system that feeds non­linear loads may still be quite low. However, the sum does not eliminate all current
harmonics. The odd multiples of the third harmonic (called “TRIPLENS”) are added
together in the neutral and can cause overheating even with balanced loads.

15.2.4 Presence of Harmonics: Consequences

In general, even harmonics, i.e. the 2nd, 4thetc., do not cause problems. Triple
harmonics, odd multiples of three, are added on the neutral (instead of canceling each
other) thus creating a condition of overheating of the wire which is extremely

50

DM-4 Power Quality Recorder

dangerous. Designers should take into consideration the three issues given below
when designing a power distribution system that will contain harmonic current:

• The neutral wire must be of sufficient gauge.

• The distribution transformer must have an additional cooling system to continue
operating at its rated capacity when not suited to the harmonics. This is
necessary because the harmonic current in the neutral wire of the secondary
circuit circulates in the delta-connected primary circuit. The circulating harmonic
current heats up the transformer.

• Phase harmonic currents are reflected on the primary circuit and continue back
to the power source. This can cause distortion of the voltage wave so that any
power factor correction capacitors on the line can be easily overloaded.

th

The 5

and the 11thharmonics contrast the current flow through the motors mak­ing its’ operation harder and shortens their average life.
In general, the higher the ordinal harmonic number, the smaller its energy is and
therefore the impact it will have on the devices (except for transformers).

15.3 POWER AND POWER FACTOR: DEFINITIONS

In a standard electric installation powered by three sine voltages the following is defined:

Phase Active Power:

(n=1,2,3)

Phase Apparent Power:

(n=1,2,3)

Phase Reactive Power:

(n=1,2,3)

Phase Power Factor:

(n=1,2,3)

Total Active Power:

Total Reactive Power:

Total Apparent Power:

otal Power Factor:

T

Pn = Vn • In • cos(

Sn = Vn• I

Qn = Sn - P

P

F n

P

TOT

Q

OT

T

S

TOT

P

F TOT

n

2

2

√

n

P

n

=

S

n

= P1 + P2 + P

= Q1 + Q2 + Q

2

= P

+ Q

√

TOT

P

OT

T

=

S

TOT

51

ΘΘ

3

TOT

)

n

Where:

V

n

= RMS value of voltage

between phase n and Neutral.

I

n

= RMS value of n phase

3

2

current.

f

n

= Phase displacement
angle between voltage and
current of n phase.

DM-4 Power Quality Recorder

In presence of distorted voltages and currents the previous relations vary as follows:

Phase Active Power:

(n=1,2,3)

Phase Apparent Power:

(n=1,2,3)

Phase Reactive Power:

(n=1,2,3)

Phase Power Factor:

(n=1,2,3)

Distorted Power Factor:

(n=1,2,3)

Total Active Power:

Total Reactive Power:

Total Apparent Power:

Total Power Factor:

∞

Pn = V

∑

kn Ikn

k=1

Sn = VnN• I

F n

2

√

P

n

=

S

n

Qn = Sn - P

P

dPFn =cosf

displacement between the
fundamentals of voltage and current

P

= P1 + P2 + P

TOT

Q

= Q1 + Q2 + Q

TOT

S

= P

√

P

TOT

F TOT

TOT

P

OT

T

=

S

TOT

1n

n

2

n

=

2

+ Q

cos(

phase

3

TOT

ΘΘ

)

kn

3

2

Where:

V

kn

= RMS value of kth

voltage harmonic between n
phase and Neutral.

I

kn

= RMS value of kth current
harmonic of n phase.
f

kn

= Phase displacement
angle between kth voltage

harmonic and kth current
harmonic of n phase.

Note:

It is to be noted that the expression of the phase Reactive Power with non sine wave­forms, would be wrong. To understand this, it may be useful to consider that both the
presence of harmonics and the presence of reactive power produce, among other
effects, an increase of line power losses due to the increased current RMS value.
With the above given relation the increasing of power losses due to harmonics is
added to that introduced by the presence of reactive power. In effect, even if the two
phenomena together contribute to the increase of power losses in line, it is not true in
general that these causes of the power losses are in phase between each other and
therefore can be added one to the other mathematically.The above given relation is
justified by the relative simplicity of calculation of the same and by the relative dis­crepancy between the values obtained using this relation and the true value.

It is to be noted moreover, how in case of an electric installation with harmonics,
another parameter called distorted Power Factor (dPF) is defined. In practice, this
parameter represents the theoretical limit value that can be reached for Power
Factor if all the harmonics could be eliminated from the electric installation.

52

DM-4 Power Quality Recorder

15.3.1 Conventions on Powers and Power Factors

As for the recognition of the type of reactive power, of the type of power factor and
of the direction of the active power, the below conventions must be applied. The
stated angles are those of phase-displacement of the current compared to the volt­age (for example, in the first panel the current is in advance from 0° to 90° com­pared to the voltage):

^

Equipment under test = Inductive Generator

Equipment under test = Capacitive Generator

`` ^

90˚

-P
Pf

-Q

-P
Pf

-Q

270˚

`` ^

Equipment under test = Capacitive Load

+P
Pf

-Q

+P
Pf

-Q

^

Equipment under test = Inductive Load

Where:

Symbol Significance Remarks

P+ Value of the active power +

-Pf Capacitive power factor +

Pf+ Inductive power factor +

-Q Value of the capacitive reactive power +

Q+ Value of the inductive reactive power +

P- Value of the active power -

-Pf Capacitive power factor -

+Pf Inductive power factor -

-Q Value of the capacitive reactive power -

+Q V

alue of the inductive reactive power -

Positive parameter

(load)

Negative parameter

(generator)

53

DM-4 Power Quality Recorder

Value Significance

P The active power (positive or negative) is defined in the panel and therefore acquires the

value of the active power in that moment.

Q The reactive power (inductive or capacitive, positive or negative) is defined in the panel and

therefore acquires the value of the reactive power in that moment.

Pf The power factor (inductive or capacitive, positive or negative) is defined in the panel and

therefore acquires the value of the power factor in that moment.

0 The active power (positive or negative) or the reactive power (inductive or capacitive,

positive or negative) is NOT defined in the panel and therefore acquires a null value.

-1 The power factor (inductive or capacitive, positive or negative) is NOT defined in the panel.

15.3.2 3 Phase 3 Wire System

In the electrical systems distributed without neutral, the phase voltages and the
power factors and phase cosj lose importance. Only the phase to phase voltages,
the phase currents and the total powers remain defined.

Phase 1

W 1-2

VAR1-2

Three-phase

Phase 2

equipment

Phase 3

W 3-2

VAR3-2

In this case the potential of one of the three phases (for example, phase 2) is taken
on as reference potential. The total values of the active, reactive and apparent
power are expressed as sum of the indications of the couples of Wattmeters,
VARmeters and VAmeters.

P

= W

1-2

= VAR

= (W

√

+ W

1-2

+ W

1-2

3-2

+ VAR

3-2

3-2

)2+ (VAR

54

+ VAR

1-2

2

)

3-2

TOT

Q

TOT

S

TOT

DM-4 Power Quality Recorder

15.4 MEASURING METHOD: OUTLINES

The instrument is able to measure: voltages, currents, active powers, inductive and
capacitive reactive powers, apparent powers, inductive and capacitive power fac­tors, analog or impulse parameters. All these parameters are analyzed in a digital
way: for each phase (voltage and current), 6 x 128 samples are acquired on a mod­ule of 16 x 20ms, repeated for the three phases.

15.4.1 Integration Periods

The storage of all the data would require a huge amount of memory. Therefore,
we’ve tried to find out a storage method that compresses the information to be
memorized, while still providing a significant amount of data. The chosen method
is that of integration. After a certain period called the “integration period”, which can
be set from 5 seconds to 60 minutes, the instrument extracts from the sampled val­ues the following:

• Minimum value of the parameter during the integration period (harmonics excluded)

• Medium value of the parameter (intended as arithmetic average of all the values
registered during the integration period)

• Maximum value of the parameter during the integration period (harmonics excluded)

Only this information (repeated for each parameter to be memorized) is saved in the
memory along with starting time and date of the integration period. Once these data
are memorized, the instrument restarts to take measurements for a new period.

15.4.2 Power Factor Calculations

According to the standards in force, the medium power factor can’t be calculated as
average of the instantaneous power factors. It must be obtained from the medium val­ues of active and reactive power. Each single medium power factor (of phase or total)
is therefore calculated, at the end of each integration period, on the medium value of
the corresponding powers independently on the fact that they must be registered or
not. Besides, for a better analysis of the type of load present on the line and in order
to have terms of comparison when studying the invoicing of the low cosj, the values
of inductive and capacitive cosj are treated as independent parameters.

55

DM-4 Power Quality Recorder

16. AFTER-SALE SERVICE

16.1 WARRANTY

Congratulations! Your new instrument has been quality crafted according to quali­ty standards and contains quality components and workmanship. It has been
inspected for proper operation of all of its functions and tested by qualified factory
technicians according to the long-established standards of our company.

Your instrument has a limited warranty against defective materials and/or work­manship for one year from the date of purchase provided that, in the opinion of the
factory, the instrument has not been tampered with or taken apart.

Should your instrument fail due to defective materials, and/or workmanship dur­ing this one-year period, a no charge repair or replacement will be made to the
original purchaser. Please have your dated bill of sale, which must identify the
instrument model number and serial number and call the number listed below:

AMPROBE / Repair Department
Phone: [phone] • Toll Free: 800-327-5060 • Fax: [phone]
Website: www.Amprobe.com

Please obtain an RMA number before returning product for repair.

Outside the U.S.A. the local representative will assist you. Above limited warranty
covers repair and replacement of instrument only and no other obligation is stated
or implied.

16.2 SERVICE

If the instrument fails to operate, check battery, test leads, etc and replace as neces­sary. If the instrument still malfunctions, please call the phone number listed below:

AMPROBE / Repair Department
Phone: [phone] • Toll Free: 800-327-5060 • Fax: [phone]
Website: www.Amprobe.com

Outside the U.S.A. the local Amprobe representative will assist you.

56

100795 Rev.B