1. SFT 2841 IN CONNECTED MODE
Prepare setting files

2. Starting the application
Click on the icon
Select the working language
Choose the operating mode:
connected
point to point via the front panel
via the network
Same access for SFT disconnected

3. Connection via the network
Choice of the network
If required: creation or modification of the network
Connection to Sepam units via the network
Starting of SFT 2841 software on the chosen station

4. SFT 2841 expert UMI
The protection and parameter setting data may be saved.
Reports may be edited.

5. PARAMETER SETTING
Parameter setting

6. Current operation Metering and operating data Parameter setting
alarm messages
tripping current
number of operations
logic status of inputs, outputs and LEDs
Parameter setting
of each protection function
of control logic
of general installation and Sepam data

7. Logipam Selection Choice in the list Apply Activate Delete
Download onto the PC
Automatic updating

8. Logipam internal resources
internal bits
counters
clocks
delays

9. General information on connected mode
Connection
Sepam type
Sepam name
Code operating mode
Remote control
Internal clock

10. General diagnosis Series 20 General characteristics Sepam status
Software versions
Sepam status
Clock with time-setting
Presence of modules
Monitoring of communication exchanges

11. General diagnosis Series 40 General characteristics Sepam status
Software versions
Sepam status
Clock with time-setting
Presence of modules
Monitoring of communication exchanges

12. General diagnosis Series 80 General characteristics Sepam status
Software versions
Sepam status
Clock with time-setting
Presence of modules
Monitoring of communication exchanges

13. Diagnosis: LED, input and output status
Series 40 & 80
Display of LEDs
Display of validated inputs
Display of outputs
Testing of 3s pulse outputs

14. Diagnosis: remote indication (TS) status
Series 40 & 80
Status transmitted via the communication link

15. Measurements Series 80 Network measurements: Current measurements rms
demand
maximum
residual
additional
Voltage measurements
phase-to-neutral
phase-to-phase
positive-sequence
negative-sequence
Frequency measurement

16. Measurements: vector diagram
Series 80
Display
voltage
current
Select
scale
référence

17. Power and energy measurements
Series 80
Power measurements
active
reactive
apparent
power factor
Energy measurements

18. Temperature measurements
Series 80
MET 148 modules

19. Network diagnosis Series 80 Unbalance ratio Phase displacement
Number of trips
Phase
Earth
Total Harmonic Distortion

20. Network diagnosis Series 80 Machine diagnosis
Differential measurements
Phase angles
Impedance measurements
Thermal overload
Running hours counter

21. Network diagnosis
Series 80
Tripping contexts
Selection by date

22. Switchgear diagnosis
Series 80
Cumulative breaking current …

23. Alarm management Series 80 Current alarms Alarm history
Not acknowledged
Clear
Reset
Alarm history
200 alarms

24. Disturbance recording
Series 80
Selection by date
Voluntary trigger
Recovery of recording

25. On-line help
Series 80
On-line help

26. MAIN POINTS TO REMEMBER

27. Network diagnosis functions Tripping current
This function gives the RMS values of the phase currents and residual currents at time of the last trip.
The measurement is defined as the maximum RMS value measured during a 30 ms interval after the activation of the O1 output.
Acquisition of tripping current TRIPI1.
RETURN

28. Machine operating assistance functions Current phase displacement
Current phase displacement between the main phase currents (I) and additional phase currents (I') (1, 2, 3) is calculated for each phase.
The angle is measured in the clockwise direction.
The information is used to check Sepam wiring when 87T protection functions are implemented. I
I’1 
RETURN

29. Metering functions Power factor (Cos)
This function gives the phase displacement between the phase currents and the phase-to-neutral voltages.
The + and - signs and the IND (inductive) and CAP (capacitive) indications give the direction of power flow and the type of load. Q P
+IND
+CAP
-CAP
-IND V I 
RETURN

30. Network diagnosis functions Phase displacement
This function gives:
phase displacement measured between the residual voltage and residual current in the trigonometric direction
phase displacement between the V1, V2, V3 voltages and I1, I2, I3 currents respectively, in the trigonometric direction
The measurements are used during Sepam commissioning to check that the voltage and current inputs are wired correctly.
The angle is positive when the current is leading compared to the voltage (trigonometric direction).
the angle is modified by 180° by the setting incomer / feeder. Io Vo 0 I V 
RETURN

31. Machine operating assistance Differential / through current
Differential / through current is calculated for the implementation of the differential protection functions 87T and 87M.
It is calculated for each phase by:
When a transformer is used (87T), the Idiff / It calculation takes into account the vector shift and transformation ratio..
The Idiff / It value is expressed with respect to In, the rated current of the main channels.
It = max ( Iadjusted , I’adjusted )
Idiff = Iadjusted + I’adjusted
RETURN

32. Metering functions Physical values measured
Sepam measures the following physical values:
phase current (3I)
residual current (Io)
phase voltage (3V)
residual voltage (Vo)
Each measured signal is processed by Sepam to produce all the values necessary for the metering, diagnosis and protection functions.
RETURN

33. Metering functions RMS measurement
RMS measurement is only used by the phase current metering function and for the thermal overload protection function (49). The RMS values take into account harmonics up the the 13th.
For all other metering and diagnosis functions, the H1 fundamental 50 Hz or 60 Hz component is used.
RETURN

34. Metering functions Residual current
This function gives the RMS value of the residual current obtained by:
measurement: Io
calculation of the sum of the phase currents: Io
Accuracy at Ino: ±1%.
Accuracy ± 2% from 0.3 to 1.5 Ino
Accuracy ± 3% from 0.1 to 0.3 Ino
The measurement range extends to 40 Ino when Io measurement is used. In the other cases, the range extends to 20 Ino.
RETURN

35. Metering functions Demand phase current
5mn
55A 63A 89A 78A 59A
100A
Demand current
Resetting to zero:
by the clear key on the display unit if one of the two screens is displayed,
by the clear command in the SFT2841 software,
via the communication link (remote control order TC4).
RETURN

36. Metering functions Peak demand current
At the end of each integration period, i.e. once the new demand current values are available, the function determines the greatest demand current value obtained since the last reset. A t
55A 63A 89A 89A 89A
100A
Peak demand current
5mn
RETURN

37. Metering functions Phase-to-phase voltage
This function gives the RMS value of the 50 or 60 Hz component of the phase-to-phase voltages.
U21 voltage between phases 2 and 1 (U21=V1-V2)
U32 voltage between phases 3 and 2 (U32=V2-V3)
U13 voltage between phases 1 and 3 (U13=V3-V1)
by calculation when 3 phase-to-earth VTs are connected,
by measurement (U21 and U32) and by calculation (U13) when 2 phase-to-phase VTs are connected,
by measurement (U21) when only one phase-to-phase VT is connected, in which case the U32 and U13 voltages are not available.
RETURN

38. Metering functions Frequency
This measurement is based on:
U21 if only one phase-to-phase voltage is available,
positive sequence voltage if the U21 and U32 measurements are available.
The frequency is not displayed (replaced by ****) if:
U21 or Vd is less than 40% of Un.
frequency is out of range.
Accuracy at Unp: ±0.01Hz
25 to 65 Hz range Sepam series40 and 80
45 to 55 Hz if 50Hz Sepam series 20
55 to 65 Hz if 60Hz Sepam series 20
RETURN

39. Metering functions Power factor (Cos)
Capacitive/inductive circuit:
If V is leading compared to I, in the trigonometric (counter-clockwise) direction, then  is positive.
A capacitive (CAP) circuit is one in which the current is leading compared to the voltage ( <0).
An inductive (IND) circuit is one in which the current is lagging compared to the voltage ( >0). V I 
CAP  I
IND V
RETURN

40. Metering functions Active, reactive and apparent power
For an incoming circuit:
Power supplied to the busbars is positive.
Power supplied by the busbars is negative.
For an outgoing circuit:
Power supplied to the busbars is negative.
Power supplied by the busbars is positive.
Direction of power flow
Direction of power flow P+ P+
RETURN