KMB SML 133 Series User manual

KMB systems, s.r.o.
Dr. M. Horákové 559, 460 06 Liberec 7, Czech Republic
tel. [phone], fax [phone]
email : [email protected], internet : www.kmb.cz
SML 133
Multifunctional Meter
Operating Manual
Firmware 1.0 / 2014
The instrument measures line and phase voltages, currents, active, reactive and apparent powers,
power factors, THD and harmonics of voltages and currents, as well as frequency in single-phase and
three-phase low, medium and high voltage power systems.
Built-in electricity meter measures electric energy in four quadrants, as well maximum active power
demand.
The instrument further allows informative measurement of temperatures within a switchboard cabinet
using an inbuilt temperature sensor.
Besides actual values, average values during preset time window are evaluated too. Maximum and
minimum values of them are registered.
The instrument feature three voltage and three fully isolated current measuring inputs.
Nominal range of the voltage inputs can be in range from 57.7/100 up to 400/690 VAC,optionally.
The current inputs can be either the „X/5A“, i.e. with 5 AAC nominal range (for standard CTs), or they
can be adopted for connection to special miniature through-hole („Pxxx“-type) or split core („Sxxx“-
type) ) current transformers. These transformers are part of instrument shipment and they can be
simply installed on measured cables. Therefore, they are convenient in applications where use of
standard xxx/5 A CTs is impossible or not optimal. As assortment of the shipped CTs starts at 5A
nominal current model, they can be installed at secondary circuit of standard xxx/5 A CTs.
The instrument can be optionally equipped with two relays with programmable function or solid-state
outputs that can be used as electricity meter impulse outputs and one digital input for general state
monitoring.
Power supply of standard instrument models has universal range 85 ÷ 275 VAC or 80 ÷ 350 VDC.
Optional power supply range is 20 ÷ 75 VDC.
The instruments can be equipped with an RS 485 or Ethernet communication interface. Then the
ENVIS software allows remotely viewing data measured. For custom design systems, the Modbus
communication protocol can be used too.
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SML133 Operating Manual
1. Putting in Operation
1.1 Instrument Connection
1.1.1 Physical
The SML 133 instrument is built in a plastic box to be installed in a distribution board panel. The
instrument’s position must be fixed with locks.
Natural air circulation should be provided inside the distribution board cabinet, and in the instrument’s
neighbourhood, especially underneath the instrument, no other instrumentation that is source of heat
should be installed or the temperature value measured may be false.
1.1.2 Power Supply
The supply voltage (in range according technical specifications) connects to terminals AV1 (No. 9) and
AV2 (10) via a disconnecting device (switch – see wiring diagram). It must be located at the
instrument’s proximity and easily accessible by the operator. The disconnecting device must be
marked as such. A circuit breaker for nominal current of 1 amp makes a suitable disconnecting device,
its function and working positions, however, must be clearly marked.
1.1.3 Measured oltages
The phase voltages measured are connected to terminals L1 (12), L2 (13), L3 (14), the common
terminal to connect to the neutral wire is identified as N (11; it stays free at delta- (3-D) and Aron- (A)
connections). It is suitable to protect the voltage lines measured for example with 1A fuses. Measured
voltages can also be connected via instrument voltage transformers.
A connection cable maximum cross section area is 2.5 mm2.
SML 133 U 400 X/5A Instrument Rear Panel
1.1.4 Measured Currents
The instruments are designed for indirect current measurement via external CTs only. Proper current
signal polarity (k, l terminals) must be observed. You can check the polarity by the sign of phase
active powers on the instrument display (in case of energy transfer direction is known, of course).
The I2k, I2l terminals stay free in case of the Aron (A) connection.
1.1.4.1 „X/5A“-Type Instruments
The current signals from 5A or 1A instrument current transformers must be connected to the terminal
pairs I1k, I1l, I2k, I2l, I3k, I3l (No. 1 ÷ 6). In the P.01 parameter (see below), set the CT-ratio.
A connection cable maximum cross section area is 2.5 mm2.
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SML133 Operating Manual
1.1.4.2 „ xxx“-, „Pxxx“-Type Instruments
The supplied current transformers (which are standard accessory) must be clamped on
measured wires and interconnected with corresponding terminal pairs I1k, I1l, I2k, I2l, I3k, I3l
(No. 41 ÷ 46) using a twisted-pair cable of maximum length of 3 m.
According the instrument model, corresponding CT type must be used.
WARNING : Connection of standard CTs with 5A or 1A nominal output current is
forbidden !!! Otherwise the instrument can be badly damaged !!!
The secondary winding of the through-hole (JP-type) transformers for the „Pxxx“-type instruments is
led by pair of fixed cables of length about 10 cm and requires a wiring block for interconnection to the
instrument terminals. It is recommended to orient the dark side of the transformer housing to the
source ("K"), the light side ("L") to the load – then, the light output cable is "k" and the dark cable is "l".
The secondary winding of the split-core (JC-type) transformers for the „Sxxx“-type instruments is led to
the screw terminals. The „K“/„L“ and „k“/„l“ orientation is marked on the CTs guide groove.
A connection cable maximum cross section area is 1.5 mm2. For example, the KU03G24 ( Nexans )
cable can be used.
Sxxx- an Pxxx- option mo els - CURRENT connector signals
pin No. signal
41, 42 I1k, I1l … L1 phase current
43, 44 I2k, I2l … L2 phase current
45, 46 I3k, I3l … L3 phase current
Note : To get better precision when using overweighted CTs, you can apply more windings of
measured wire through the transformer. Then you must set the multiplier parameter ( P.01
parameter,see below). For example, for 2 windings applied, set the multiplier to 1/2 = 0.5 .
For standard connection with 1 winding, the multiplier must be set to 1.
1.2 Basic Operation
On connecting power supply the display shows all of the segments, then gradually screens
with the instrument type and setting of basic parameters :
1. line 1 : 1 3 3 - instrument type number
line 2 : 5 A - current input type
line 3 : n. n n - firmware version number
2. when connection of voltage via voltage transformers set (otherwise the screen is skipped) :
line 1 : U t - voltage transformer connected identification
line 2 : nominal primary voltage [kV]
line 3 : 0. 1 - nominal secondary voltage [kV]
3. line 1 : C t - current transformer/range specification
line 2 : nominal primary current [A] for X/5A- current input type instruments, or current range
for the Sxxx- and Pxxx-type instruments
line 3 : nominal secondary current [A] for X/5A-type instruments, or multiplier for the S- and
P-type instruments
4. line 1 : F U - nominal frequency and voltage
line 2 : nominal frequency
line 3 : nominal voltage
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SML133 Operating Manual
Then the instrument starts display actual measured values. Simultaneously, if the instrument has a
communication line, it can be set and its measured values read via the communication link using a
PC.
1.2.1 Setup
At this moment it is necessary to set instrument parameters that are essential for proper instrument
measurement :
•CT ratio – parameter 01 (or multiplier for the “Sxxx“ or “Pxxx“ - current input type
instruments)
•type of connection – parameter 02 (wye, delta, Aron)
•mode of connection – parameter 04 (direct or via VT connection, VT ratio)
•nominal frequency fNOM and nominal voltage UNOM – double parameter 05
Usually, it is only necessary to adjust the CT ratio. Next example shows how to do it :
Assuming that the ratio of used CTs is 750/1 A. First off all, it is necessary to switch display from
measured data branch (the ULN screen on the example below) to the parameter branch with the
button. The branch is indicated with the symbol . Parameter 01 appears – this parameter is the
CT ratio and its default value is 5/5 A.
Now enter editing mode by pressing and holding the until the value gets flashing.
As soon as the value flashes, release the . Now you can change it. Increase primary value by
pressing of the . If you keep it pressed two-speed autorepeat helps to reach target value quickly.
Then use multiple pressing of and for fine setup.
To change the secondary value, simply press the . The button serves as toggle switch between 5
and 1.
CT Ratio Change Proce ure Example
Target CT value is prepared now and we can leave the edit mode with (short) pressing the . The
value is stored into the instrument memory and the flashing stops.
Now you can scroll to other parameters with and and edit them in a similar way or you can
return to the measured data branch with the .
The summary of all instrument parameters is stated in the table below. Their description is stated in
following chapters.
4
long
mutli
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SML133 Operating Manual
1.2.2 Measured Data
The instrument starts display actual measured values on power-up. The screen that was selected
before the last powerdown is displayed. You can navigate through all of measured and evaluated
values with , and buttons as shown on the Measure Data Navigation Chart below.
If phase values displayed, individual L1 / L2 / L3 - phase value is shown in the line 1 / 2 / 3. If a three-
phase value is displayed, it is shown in the line 2 and the Σ symbol appears.
The quantities' meaning and evaluation formulas can be found in the appropriate chapter further
below.
Most of data are arranged in four columns :
•Actual …. actual values, refreshed each 3 measurement cycles (30/36 mains cycles)
•Avg …...... average values per appropriate averaging period (see below)
•AvgMax ... maximum of the avg-value reached since the last clearing
•AvgMin …. miniimum of the avg-value reached since the last clearing
You can scroll inside a column down and up with the and keys and move horizontally from a
column to the next right one cyclically with the key.
Exception : Only actual values of harmonics and electrical energy are available. These values are
arranged in different way – see further below.
1.2.2.1 Average Values
Average values are processed according set averaging method and length of averaging window
(individually for “U/I”-group and “P/Q/S”-group of quantities). Maximum and minimum values of them
are registered into the instrument's memory. The maximums are displayed in the “AvgMax” column
and they are identified with the ▲symbol in the front of the value. Analogically, the minimums in the
“AvgMin” column are identified with the ▼symbol.
Neither maximum nor minimum of cosφ values are evaluate ue to special character of the
quantity. Similarly, these extreme values are not evaluate at harmonics.
You can clear the “AvgMax”/“AvgMin” values. All of the maximums/minimums of appropriate quantity
group are cleared simultaneously. To do it, follow next :
•navigate on corresponding AvgMax or AvgMin value
•press the key until the value starts flashing
• with the or key, choose the C L r option
•then confirm by pressing the
The appropriate group ( U/I or P/Q/S ) of average maxs/mins is affecte by single clearing
only ! Each group must be cleare in ivi ually.
If the instrument is locke , the clearing is not possible.
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SML133 Operating Manual
SML133 Measure Data Branch Navigation Chart
6
line-to-line
voltages
active phase
powers
ULL
ULN
I
phase currents
PF
3-phase power
factor
ΣPF
phase power
factors
P
ΣP
active 3-phase
power
Q
reactive phase
powers
ΣQ
reactive 3-phase
power
S
apparent phase
powers
ΣS
apparent 3-phase
power
TDHU, Uh
TDHI, Ih
3-phase energies,
3-phase average
active power max.
ΣE,ΣPavgmaxE
f, T
frequency,
temperature
current total harm.
distortion,
current harmonics
Actual Avg AvgMax AvgMin
Full Sp ctrum Valu s Branch
PF, ΣPF, P, ΣP, Q, ΣQ
Fundam ntal
Harmonic Valu s
Branch
cos φ / tanφ /φ
Σcos φ / Σtanφ / Σφ
(act. valu s only)
Pfh
ΣPfh
Qfh
ΣQfh
see the next
figure for details
(fundamental harmonic branch
indicated with the “H character)
similarly
→ Avg → AvgMax → AvgMin
→ Avg → AvgMax → AvgMin
→ Avg → AvgMax → AvgMin
→ Avg → AvgMax → AvgMin
Electricity Meter Row :
1. Active – Import
2. Active – Export (-)
3. Reactive – Inductive (L)
4. Reactive – Capacitive (C)
5. ΣpavgmaxE
(Default „8E+Pmax“ format.
For „6E“ optional electricity
meter format see next
figure.)
Voltage THD & Harmonics
Row
Odd Actual Harmonics Only,
up to 25th Order
Current THD & Harmonics
Row
Odd Actual Harmonics Only,
up to 25th Order
→
→ → →
voltage total harm.
distortion,
voltage harmonics
line-to-neutral
voltages

SML133 Operating Manual
SML133 Fun amental Harmonic Values Branch
Optional “8E” Electricity Meter Display Format
1.2.2.2 Full pectrum Values P/Q/PF & Fundamental Harmonic Values Pfh/Qfh/cos φ
As standard, active and reactive powers (and therefore power factor) are evaluated from full spectrum
of harmonic components of both voltage and current.
Sometimes (for example for power factor compensation system checking), it is useful to know
fundamental harmonic part of these quantities too. Such quantities are marked Pfh, Qfh, cos φ.
As you can see on the navigation chart you can navigate from the full spectrum values branch with the
key further right into the fun amental harmonic values branch and vice versa. To distinguish
actual displayed branch, the H symbol is displayed for the fundamental harmonic branch.
Exception : Actual values only of fundamental harmonic power factor – the cos φ – are evaluated (no
average values available). Next, this fundamental harmonic power factor can be expressed not only
as cos φ, but as tan φ or φ too, depending on setting of parameter 09.
1.2.2.3 Fundamental Harmonic Power Factor Formats cosφ/tanφ/φ
The fundamental harmonic power factor can be expressed not only as cos φ, but as tan φ or φ too,
depending on setting of parameter 09.
For outright specification of the quadrant, the power factor of the fundamental harmonic component is
accompanied with two attributes :
7
Avg AvgMax AvgMin
→ → →
ΣEP+ ΣEP- ΣEQL+ ΣEQL- ΣEQC+ ΣEQC- ΣES+ ΣES-
active phase
powers
cos (tan,φ)
3-phase power
factor
Σcos(tan,φ)
phase power
factors
Pfh
ΣPfh
active 3-phase
power
Qfh
ΣQfh
reactive 3-phase
power
reactive phase
powers
( actual values only )
( actual values only )
Actual

SML133 Operating Manual
•a sign ( + or - ), which indicates polarity of appropriate active power
•a symbol or , which indicates the power factor character
For detailed information see chapter Power, Power Factor an Unbalance Evaluation Metho below.
At the following figures there are examples of three-phase fundamental power factor presentations :
•the left figure : Σcos φ = 0.98 inductive (choke symbol displayed). Furthermore, active three
phase power is being negative, therefore the leading “minus”-sign ( and the symbol
displayed )
•the middle figure : Σtan φ = 0.20 inductive. Active three phase power is positive.
•the right figure : Σφ = 8 degrees inductive. Active three phase power is positive.
On the figure on the left, there is phase cos φ values example :
•cos φ1 = 0.97 inductive. L1-phase active power is currently
negative (because of leading “minus”-sign)
•cos φ2 = 0.94 inductive ( L2-phase active power currently
positive )
•cos φ3 = 0.99 capacitive ( L3-phase active power currently
positive )
1.2.2.4 THDs and Harmonic Components
You can check actual values of both voltage and current THDs and harmonic components in
appropriate rows (see the Measure Data Navigation Chart ).
When you scroll to one of this rows, THD values of all measured phases are displayed as default.
Symbols THD - - LN or THD - A indicate phase voltage or current THD values, respectively.
With the key you can switch to harmonic components. The symbol H appears, indicating harmonic
components (of voltage or current). Symbol % means that the values are expressed in percent of
fundamental harmonic component. Order of harmonics just displayed flashes periodically in the
display middle line – for example, string H03 means 3rd harmonics.
By repetitive pressing of the key you can check other harmonics. Although the instrument
evaluates all of the harmonic components up to 40th order internally, only odd components to 25th
order can be viewed of its display (full spectrum od the harmonics is available via communication
interface only).
1.2.2.5 Electricity Meter
Electricity meter comprises three-phase energy data and maximum tree-phase active power demand
value. The values are situated in particular row.
8
Fun amental Harmonic Power Factor Formats
Fun amental Harmonic
Power Factor Sign &
Character

SML133 Operating Manual
Depending on the parameter 08 setup, two electricity meter display modes can be chosen :
•“4E Pmax” mode (default)
•“8E” mode
1.2.2.5.1 “4E+Pmax” Display Mode
In this mode, first four windows contain three-phase energies of four-quadrants :
•ΣEP+ … three-phase imported active energy, indicated with Σ - kWh (or MWh or kMWh =
GWh)
•ΣEP- … three-phase exported active energy, indicated with Σ - kWh and preceeding ― sign
•ΣEQL … three-phase inductive reactive energy, indicated with Σ - k Arh – L
•ΣEQC … three-phase capacitive reactive energy, indicated with Σ - k Arh - C
Each value occupies all of three display lines, 8 digits before the decimal point and
one after it. For the exaple at left, ΣEP = 293745.8 kWh.
The values are registered since the last clearing. To clear the energies, display any of them and then
follow the same procedure as for max/min average values. All of the energies are cleared
simultaneously ant start to count from zero again.
In the 5th window there is
•ΣPavgmaxE … maximum of three-phase average active power (power demand), indicated with Σ
- kW - ▲and bar over the value
The value contains maximum of three-phase average active power since the last clearing. Averaging
method and averaging period for this value can be set regardless of the method of standard average
values, described above. The quantity is marked with the “E” letter to distinguish from the standard
maximum average quantities.
Similarly as the energies, the value can be cleared independently.
If the instrument is locke , clearing is not possible.
If the instrument is equippe with a communication interface, the values can be cleare
remotely.
1.2.2.5.2 “8E” Display Mode
In this mode, reactive energies registered separately depending on actual three-phase active power
(ΣP) sign are displayed (“six-quadrant ” mode; such format can be convenient for renewable sources
monitoring, for example) :
•ΣEP+ … three-phase imported active energy, indicated with Σ - kWh (or MWh or kMWh =
GWh)
•ΣEP- … three-phase exported active energy, indicated with Σ - kWh and preceeding ― sign
•ΣEQL+ … three-phase inductive reactive energy registered during the ΣEP value was positive
(import); indicated with Σ - k Arh – L
•ΣEQL- … three-phase inductive reactive energy registered during the ΣEP value was negative
(export); indicated with Σ - k Arh – L and preceeding ― sign
•ΣEQC+ … three-phase capacitive reactive energy registered during the ΣEP value was
positive; indicated with Σ - k Arh – C
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SML133 Operating Manual
•ΣEQC- … three-phase capacitive reactive energy registered during the ΣEP value was
negative; indicated with Σ - k Arh – C and preceeding ― sign
Furthermore, energies in VAh are available too :
•ΣES+ … three-phase apparent energy registered during the ΣEP value was positive; indicated
with Σ - k Ah
•ΣES- … three-phase apparent energy registered during the ΣEP value was negative; indicated
with Σ - k Ah and preceeding ― sign
The three-phase active power demand ΣPavgmaxE is not displayed in this mode.
1.2.3 Instrument State Symbols
Except of measured data, the instrument indicates following states with dedicated symbols :
• …........ Export of three-phase active power. Displayed when the ΣP value is negative.
• / … A1(top) and A2 (bottom) alarm lights off / on. See output setup below.
• …......... DI1 digital input state is active.
• …......... Instrument parameters are displayed.
1.2.4 Instrument Parameters
For proper operation in particular conditions, the instrument must be set. The instrument setup is
determined using parameters, for example the current transformer [CT] conversion, type of measured
voltage connection (direct connection or via a voltage transformer [VT] and its ratio), and connection
configuration (wye / delta / Aron). Overview of all the parameters is listed in the table below.
To check or edit the parameters, press the key. As default, parameter group 01 is displayed and
symbol (wrench) indicates, that setup data are displayed now.
The parameters are arranged in groups, numbered from 00 up. The number of group
is displayed in the first line in format - P. n n (with preceding dash). You can
browse through the parameter groups with the or keys.
If one parameter only in the group, its value is in the bottom line as shown at the
example (nominal power 400 kVA).
If two parameters in the group, usually the first of them is displayed in the 2nd line and
the second in the 3rd line ( nominal frequency 50 Hz and nominal voltage 230 V).
To edit a particular parameter, scroll to its group. Then press and hold the until the value gets
flashing. Now release the key and set target value with the or , or the key for some of
parameters. You can use autorepeat function by keeping one of the arrow keys pressed too. Finally,
press the and the value is stored into the memory.
If more parameters in the group, the first one is chosen when entering editing mode for the first time. If
you want to modify the second parameter only, simply cancel editing of the first parameter without any
change and reenter the editing again – now the second parameter is chosen.
To return back to measured values display, simply press the key.
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SML133 Operating Manual
SML 133 Instrument Parameters
# parameter group range default comment
00 lock LOC / OPN OPN see Instrument Setup Locking /
Unlocking
01 “X/5A” models : CT – ratio
row 2 : nominal primary current
row 3 : nominal secondary current
“S” and “P” models :
row 2 : nominal primary current range
(fixed)
row 3 : multiplier
primary : 1A ÷ 10 kA
secondary : 5A / 1A
5 / 5 A secondary current selection with
the key
02 connection type 3Y / 3D / 3A 3Y
04 connection mode: direct (- - -) or VT–ratio:
row 2 : primary U [ kV ]
row 3 : secondary U (0.1 kV fixed)
primary: 0.1kV÷1MV direct
(- - -)
05 fNOM, UNOM
row 2 : fNOM [ Hz ]
row 3 : UNOM [ V / kV ]
50 / 60 Hz
50 V ÷ 1MV
50
230
UNOM specification depending on
connection mode :
- direct : line-to-neutral
- via VT : line-to-line
06 ΣPNOM [ kVA / MVA ] 1 kVA ÷ 999 MVA -
07 averaging period
row 2 : for U/I group
row 3 : for P/Q/S group
0.01 ÷ 60
(1 sec÷ 60 mins) 1 min
15 min
floating window type averaging
method applied as default;
thermal method indicated with
symbol ▲
08 avg period for ΣPavgmaxE,, El. meter d. mode
line 2 : averaging period for ΣPavgmaxE,
line 3 : Electricity meter display mode
0.01 ÷ 60
(1 sec÷ 60 mins)
“4E Pmax” / “8E”
15 min
“4E
Pmax”
floating window type averaging
method applied
09 fund. harmonic PF display format cos / tan / fi cos
10 backlight AUT / ON ON AUT-mode : the backlight is
switched off automatically after
approx. 5 minutes if no key is
pressed to decrease power
dissipation.
11 output setup
row 2 : output DO1
row 3 : output DO2
standard type : “-O-”
impulse type : pulses / kWh(kvarh)
control energy symbol :
•none … ΣEP
• - … ΣEP-
• … ΣEQL
• … ΣEQC
“ - - -” = off
“-O-” = standard
output
0.001 ÷ 999 =
impulse output
- - -
( off )
control energy selection with the
key
Standard type output can be set
via communication line only, not
from instrument panel. Symbol
▲indicates different setup of the
alarm light A1 from the DO1 and
the A2 from the DO2
If impulse type output set from
instrument panel, the A1 and the
A2 alarm lights are set identically
as the DO1 and the DO2,
respectivelly.
15 communication :
row 2 : address
row 3 : rate [ kBd ]
1 ÷ 255
4.8 ÷ 115
1
9.6
16 communication :
nunber of data bits and parity 8 / 9-n / 9-E / 9-0 8
KMB / Modbus protocol
automatic detection; for the KMB
protocol set to “8”
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SML133 Operating Manual
1.2.5 Instrument Setup Locking / Unlocking
When shipped, parameter editing is unlocked, that means :
•all of the parameters can be edited
•standard average maximums / minimums, electricity meter energies ΣEP , ΣEP-, etc., and
electricity meter maximum power demand ΣPavgmaxE can be cleared
After being put in operation, such operations can be locked (=disabled) to protect the instrument
against unauthorized changes. Then operator can only check measured values and parameters, but
cannot change anything, excluding special parameter No. 00, that serves as the instrument lock. It
has one of two values :
L O C ....... instrument is locked
O p n ....... instrument is unlocked (open)
If the instrument is locked, you can unlock it using the following procedure, which is similar to editing
of other parameters:
1. Press the key and scroll to parameter group 00 with arrow keys – value L O C is
displayed.
2. Press the and hold it down until the value is replaced with flashing number between
0 0 0 and 9 9 9. As an example, you can imagine flashing 3 4 5 is displayed.
3. Press the following sequence: , , , . The value changes gradually to
3 4 4, 3 4 5, 3 4 6, 3 4 5, so the same value is shown at the end as at the
beginning.
4. Press the . The flashing number is replaced with O P n, indicating unlocked state.
The digit shown while entering the unlocking keypress sequence is random and it is not important for
correct unlocking (it is there only to confuse). Only the sequence of keys pressed is important and
must be followed exactly.
The instrument can be locked in a way analogous to unlocking but it is necessary to press any
keypress sequence that is different from the unlocking sequence noted above.
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SML133 Operating Manual
2. Detailed Operation Description
2.1 Method of Measurement
The measurement consists of three processes being performed continuously and simultaneously:
frequency measuring, sampling of voltage and current signals and evaluation of the quantities from
the sampled signals.
2.1.1 oltage Fundamental Frequency Measurement Method
The voltage fundamental frequency is measured continuously and evaluated every 10 seconds.
Logical sum of all voltage signals is led through a low-pass filter and then processed.
The fundamental frequency output is the ratio of the number of integral mains cycles counted during
the 10 second time clock interval, divided by the cumulative duration of the integer cycles.
If value of frequency is out of measuring range, such state is indicated with flashing symbol Hz.
2.1.2 oltage and Current Measurement Method
Both voltage and current signals are evaluated continuously as required by IEC 61000-4-30, ed. 2
standard. The unitary evaluation interval, a measurement cycle, is a ten / twelve ( value behind slash
is valid for fNOM = 60 Hz ) mains cycles long period ( i.e. 200 ms at frequency equal to preset fNOM ),
which is used as a base for all other calculations.
The sampling of all voltage and current signals is executed together with the frequency of 128 / 96
samples per mains cycle. The sampling rate is adjusted according to the frequency measured on any
of the voltage inputs U1, U2, U3. If the measured frequency is in measurable range at least on one of
these inputs, then this value is used for subsequent signal sampling. If the measured frequency is out
of this range, the preset frequency value ( fNOM ) is used and measured values may be incorrect.
Effective values of voltages and currents are calculated from sampled signals over the measurement
cycle using formulas (examples for phase No. 1) :
Phase voltage (effective value) :
∑
=
=
n
i
Ui
U
n
1
1
1
2
1
Line voltage (effective value) :
∑
=
−
=
n
i
UiUi
U
n
1
21
12
)(
2
1
Current (effective value) :
∑
=
=
n
i
IiI
n
1
1
1
2
1
where : i …........ sample index
n ........... number of samples per measurement cycle ( 1280 / 1152 )
Ui1, Ii1 … sampled values of voltage and current
The data for the longer measurements are aggregated from these measurement cycles.
Measured phase voltages U1 to U3 correspond to the potential of terminals OLTAGE / U1 to U3
towards the terminal OLTAGE / N.
Three current signals - I1, I2, I3 - are measured. Another current is calculated from samples of directly
measured ones as negative vector sum of all measured current vectors ( Kirchhoff rule ). The
calculated current is referenced as IPEN. The IPEN value is not displayed, it is available on a PC via
communication with ENVIS program only.
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SML133 Operating Manual
2.1.3 Harmonics and THD Evaluation Method
Entire spectrum of harmonic components and THD is evaluated discontinuously - periodically every
second from 10 / 12 mains cycles long signal according to IEC 61000-4-7 ed.2 as harmonic sub-
groups (Hsg).
Following quantities are evaluated :
Harmonic components of voltage and current up to 40th order : Uih1, Iih1
( i …. order of harmonic component )
Absolute angle of voltage harmonic component phasor : φUih1
Current harmonic component phasor angle relative to phasor Ufh1 : φIih1
Relative angle between correspondent voltage and current phasors : Δφi1
Total harmonic distortion of voltage :
%100
1
1
40
21
2
1
1 ×
∑
=
= i
U
Uih
hU
THD
Total harmonic distortion of current :
%100
1
1
40
21
2
1
1 ×
∑
=
= i
I
Iih
hI
THD
2.1.4 Power, Power Factor and Unbalance Evaluation Method
Power and power factor values are calculated continuously from the sampled signals according to
formulas mentioned below. The formulas apply to basic type of connection – wye (star).
Active power :
∑
=
∆××=
40
1
1,1,
1,
1 cos
k
kkk
IUP ϕ
Reactive power :
∑
=
∆××=
40
1
1,1,
1,
1 sin
k
kkk
IUQ ϕ
where : k … harmonic order index, odd components only
Uk,1, Ik,1 … the kth harmonic components of voltage and current ( of phase 1 )
Δφk,1 ... angle between the kth harmonic components Uk,1, Ik,1 ( of phase 1 )
( these harmonic components of U and I are evaluated from each measurement cycle )
Apparent power :
111 IUS ×=
Power factor :
111 /SPPF =
Three-phase active power: :
321 PPPP ++=Σ
Three-phase reactive power :
321 QQQQ ++=Σ
Three-phase apparent power :
321 SSSS ++=Σ
Three-phase power factor :
SPPF ΣΣ=Σ /
Fundamental harmonic component quantities :
Fundamental harmonic power factor :
1
cos ϕ ∆
(or
1
tan ϕ ∆
, Δφ1 , optionally)
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SML133 Operating Manual
Fundamental harmonic active power :
111
1 cos ϕ ∆××= IfhUfhPfh
Fundamental harmonic reactive power :
111
1 sin ϕ ∆××= IfhUfhQfh
Fundamental harmonic three-phase active power :
321 PfhPfhPfhPfh ++=Σ
Fundamental harmonic three-phase reactive power :
321 QfhQfhQfhQfh ++=Σ
Fundamental harmonic three-phase power factor :
))(cos(cos Pfh
Qfh
arctg
Σ
Σ
=∆Σ ϕ
Powers and power factors of the fundamental harmonic component (cos φ) are evaluated in 4
quadrants in compliance with the standard specifications, see figure below.
I entification of consumption- supply an the character of reactive power accor ing to phase
ifference
For outright specification of the quadrant, the power factor of the fundamental harmonic component –
cos φ – is expressed according to the graph with two attributes :
•a sign ( + or - ), which indicates polarity of active power
•a character ( or ), which indicates the power factor character ( the polarity of reactive
power relative to the active power )
Voltage and current unbalance evaluation is based on negative/positive sequences of voltage and
current fundamental harmonic components :
Voltage unbalance :
%100
__
__
×=
sequencepositivevoltage
sequencenegativevoltage
unb
U
Current unbalance :
%100
__
__
×=
sequencepositivecurrent
sequencenegativecurrent
unb
I
Current negative sequence angle : φnsI
All of angle values are expressed in degrees in range [ -180.0 ÷ 179.9 ].
15
Ir+
Ia+
S
Q
P
Ir-
Ia-
ϕ
quadrant I
active power import
reactive power import
power factor inductive (L) character
quadrant II
active power export
reactive power import
power factor capacitive (C) character
quadrant I
active power import
reactive power export
power factor capacitive (C) character
quadrant III
active power export
reactive power export
power factor inductive (L) character

SML133 Operating Manual
2.1.5 Temperature
The temperature is measured with built in sensor and updated each approx. 10 seconds.
2.2 Measured Values Evaluation and Aggregation
As described above, measured values are evaluated according to IEC 61000-4-30 ed.2, based on
continuous (gap-less), 10 / 12 mains cycles long intervals ( measurement cycle ) processing.
Further aggregation of the actual values from this evaluation is used to obtain values for displaying
and recording.
2.2.1 Actual alues Evaluation and Aggregation
Actual ( instantaneous ) values of measured quantities, that can be viewed on instrument's display,
are evaluated each isplay refresh cycle as average of integral number of measurement cycle values.
The display refresh cycle is preset to 3 measurement cycles , corresponding approx. to 0.6 sec
display refresh cycle duration.
Exceptions :
•frequency – the value is refreshed each frequency measurement cycle (see above)
•voltage and current harmonic components – the last measurement cycle values are
displayed (no averaging). Only odd harmonic components to 25th order are displayed. Higher
components are available via communication link only.
•temperature – the value is refreshed each temperature measurement cycle (see above)
•
Actual values, read from an instrument via a communication link for monitoring purposes are
evaluated from one – the last – measurement cycle only.
2.2.2 Average alues Evaluation
From measurement cycle values, average values of all basic quantities are calculated. The averaging
period in range from 1 second to 1 hour can be used.
As default, the floating win ow averaging method is applied. An internal cyclic buffer is used to store
auxiliary partial averages. The buffer has depth of 60 values. If preset average period is 1 minute or
shorter, partial averages of a quantity are buffered each second and new average values are updated
from the preset averaging period each second. If the preset average period is longer than 1 minute,
partial averages for longer duration are buffered and the average values are updated less frequently
( for example, if the preset average period is 15 minutes, partial averages are buffered each 15
seconds and average values are updated with this frequency ).
At instruments equipped with communication link, the thermal averaging method sen be set too. An
exponential function simulation is used to get the thermal dependence. Unit step time response
depends on the preset averaging period – during this period, an average value reaches about 90 % of
unit step amplitude.
The averaging period can be set in parameter group No. 07 independently for two groups of
quantities : so called U/I -group and P/Q/S -group. Following table lists processed quantities of both
groups.
Average Values Groups
Average values group Averaged quantities
“ U / I ” ULL, ULN, I, f, T
“ P / Q / S ” P, Q, S, PF, Pfh, Qfh, cosφ
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SML133 Operating Manual
Preset averaging parameters note above are vali for so calle stan ar average values.
For the maximum power eman ΣPavgmaxE in the Electricity Meter group, separate
parameter is use (see below).
2.2.3 Embedded Electricity Meter
For the electric energy measurement, a stand-alone functional unit - an electricity meter - is
implemented inside instruments. Except of electric energy, maximum active power demands are
registered in the unit.
2.2.3.1 Electric Energy Processing
Measured values of electrical energy are recorded separately in six “quadrants” :
•active energy consumed (EP+, import), active energy supplied (EP-, export)
•reactive energy registered at the three-phase active energy being consumed (imported) :
inductive (EQL+) and capacitive (EQC+) energy
•reactive energy registered at the three-phase active energy being supplied (exported) :
inductive (EQL-) and capacitive (EQC-) energy
Both single-phase and three-phase energies are processed. But on the instrument display, only three-
phase (Σ) values can be viewed. Desired presentation format can be set with parameter 08.
Internal energy counters have sufficient capacity in order not to overflow during the whole instrument
lifetime. On the instrument's display only 9 digits can be viewed – therefore, after energy value
exceeds 99999999.9 kWh/kvarh, instrument's display format automatically switches to MWh/Mvarh,
then to GWh/Gvarh.
2.2.3.2 Maximum Active Power Demand Registration
From the instantaneous measured values of all active powers the instrument evaluates their average
values per preset period using preset averaging method – active power demands. Note that the active
power demand, which is evaluated in the electricity meter unit (ΣPA GE), is processed individually and
its averaging period is presetable independently on standard average values. Its current value is not
available on the display - only its registered three-phase maximum ΣPavgmaxE is.
The averaging method if fixed – the floating window type. The averaging period can be set in range
from 1 to 60 minutes.
The maximums can be cleared independently of standard average maximums/minimums.
2.3 Display Contrast
Although the display contrast is temperature compensated, there can be sometimes
necessary to tune it slightly. To do it, press keys and simultaneously and keep pressed.
Then message C O n appears in the first line and the contrast value in the second one.
Now, if the display too light, keep the pressed and increase with repetitive pressing of the key.
Likewise, if too dark, keep the and adjust with the key.
Finally, release the keys and new contrast is set.
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SML133 Operating Manual
3. Digital Outputs & Input
Instruments can be optionally equipped with a combination of outputs and inputs. A summary of
possible variations and connection examples at the end of this manual.
Following inputs & outputs are available :
•two digital outputs – relay ( electromechanical, R ) or impulse (solid-state, I )
•one digital input
Furthermore, all of instrument models feature two “alarm ” lights A1 and
A2 for indication of various states, that can be considered as other
special digital outputs. Function of these lights can be set in the same
way as at standard digital outputs.
The behaviour of digital outputs can be programmed according to requirements as :
•transmitting electricity meter impulse output mo e
•stan ar output mo e , e.g. as a simple two-position controller or a defined status indicator
•remote controlle output mo e ( by an external application via a communication link )
The digital input DI1 state is indicated with the symbol and can be used for state monitoring via a
communication link only.
3.1 Ouputs & Input Connection
Digital inputs & outputs are connected to terminals on a rear panel of an instrument according to the
following table. A connection cable maximum cross section area is 1.5 mm2.
Connection of Digital Outputs & Input
pin No. signal
15, 16 DO1A, DO1B … digital output DO1
17, 18 DO2A, DO2B … digital output DO2
19, 20 DI1A, DI1B ….... digital input DI1
All of digital outputs and input are isolate not only from instrument internal circuits but mutually too.
3.1.1 Relay Output Connection
A SPST-NO ( single-pole, single-throw, normally open ) relay type is used. Maximum allowable
voltage and load current according technical specifications must be observed.
3.1.1.1 Impulse Output Connection
Impulse outputs are accomplished by a semiconductor switching device. It is assumed that the input
optocouplers of the external recording or controlling system will be connected to these outputs via
current–limiting resistors. The signal polarity is free.
3.1.1.2 Digital Input Connection
The input supposes a voltage signal of appropriate magnitude is connected to the the DI1 terminals
(see technical specifications). The signal polarity is free.
If the voltage exceeds declared level, the input is activated and the symbol is displayed.
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A1
A2
DI1

SML133 Operating Manual
Usual 12 or 24 V DC/AC signals can be connected directly. If you need to connect a voltage signal of
magnitude exceeding maximum digital input voltage, external limiting resistor of appropriate rating
must be used.
3.2 Outputs etup
Digital outputs ( including alarm lights ) function can be set either as stan ar output or as electricity
meter impulse output.
The DO1 / DO2 output function can be checked in parameter group 11. Possible setup options are :
•- - - ... the output DO1/2 is disabled
•- 0 - ... the output DO1/2 is set to standard output mode (detailed setup available using
the ENVIS program via a communication line only)
•n n n ... the output DO1/2 is set to impulse output mode with nnn pulses per kWh; the
control quantity is ΣEP (no symbol shown). Other control quantities options according
accompanying symbol :
• - … ΣEP-
• … ΣEQL
• … ΣEQC
Example :
Output DO1 : set to standard output mode (details via communication link only)
Output DO2 : set to pulse mode, 20 pulses/kWh of energy ΣEP-
The alarm lights A1, A2 setup is not displayed, it is available via a communication line only. You can
only check if the setup is the same as corresponding DO1/DO2 setup – see below.
The impulse output function can be set from the instrument panel using parameter group 11.
The standard output function can be used at instruments equipped with communication link only – it
can be adjusted only via connected PC using ENVIS program ( see ENVIS program manual ).
If any of signal lights A1, A2 is set, the outlines of both lights appear on the display. They stay hidden
when function of both lights is disabled.
3.2.1 Impulse Output Mode
Any of digital outputs or alarm lights can be set as transmitting electricity meter. The frequency of
generated impulses can be set depending on values of measured electric energy by the embedded
electricity meter unit.
You can set to impulse output mo e not only the I-type (soli -state) outputs, but the R-type
(electromechanical relay) outputs too. But note lifetime of electromechanical relays, they
have limite number of switchings.
The outputs DO1/2 can be set to impulse output mode both manually from the instrument panel and
remotely via a communication line. The manual setup is available in parameter group 11. After
entering editation, set edited parameter (range 0.001÷999) with arrow keys and select desired energy
with the key.
Example :
Output DO1 : 0.1 pulses/kWh = 1 pulse / 10 kWh, energy ΣEP (no additional
symbol)
Output DO2 : 5 pulses/kvarh , energy ΣEQL (due to symbol )
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SML133 Operating Manual
By setting any of the DO1/02 outputs from the instrument panel, correspon ing alarm light
A1/A2 is set in the same way automatically too. Then the DO1/DO2 activity can be checke
by the A1/A2 lights on the instrument isplay. Separate setup of the lights is available using
the ENVIS program via a communication line only. If any of lights is set ifferent from
correspon ing DO1/DO2 output the symbol ▲ precee ing appropriate setup appears.
Even if an instrument is equippe with neither any igital output nor any communication line,
you can set impulse function of alarm lights A1, A2 by setting the DO1/DO2 outputs.
After the impulse function mode is set, every 5 seconds the instrument executes evaluation of the
measured electric energy. If the increment of recorded electric power is higher or equal to the quantity
of power per one impulse, the instrument will transmit one, or if needed, several impulses. The
mentioned description shows that at higher frequency of impulses, their transmission is not
continuous, but comes in pulse bursts every 5 seconds.
The impulse output signal is in compliance with so-called SO-output definition.
3.2.2 Standard Output Mode
For the standard output mode setup you need to use the ENVIS program, therefore it can be used at
instruments equipped with a communication line only.
The figure below describes standard digital output operation. For complete output setup, following
functions need to be set :
•input events
•output control formula
•output type
Stan ar igital output setup
20