N-DIN-MSG
(2044)
Doc. N°
MO-0348-ING
Copyright 2010 (19)
Fw
RMB
360.11.0.x
FFP
360.6.0
Date
25.02.2008
Rev.
0
Pag.
5
of
31
2.1 - Power Supply
The auxiliary power is supplied by a built-in module fully isolated an self protected.
Two options are available:
24V(-20%) / 80V(+15%) a.c.
80V(-20%) / 230V(+15%) a.c.
a) -
b) -
24V(-20%) / 90V(+20%) d.c.
90V(-20%) / 250V(+20%) d.c.
Before energising the unit check that supply voltage is within the allowed limits.
2.2
– Operation and Algorithms
2.2.1
– Reference Input Values
Display
Description
Setting Range Step
Unit
Rsrvd
Reserved
Freq
50
Hz
System rated frequency
50 -
60
10
Hz
R_int
160
Internal resistance of MSG-2044 (the value is reported on front
face of MSG-2044 module)
1 - 1000
1
2.2.2
– Input quantities
2.2.2.1
– Frequency (Freq) of the test voltage
The relay can operate either with 50Hz or 60Hz.
The rated Frequency “ Freq “ must be set accordingly.
2.2.2.2
– Current inputs
The relay directly displays the r.m.s. “mA” value of the Fault Currents “
Is
“ and “
I
d
” flowing in
each of the section under supervision.
(In cable monitoring “Is” = fault current between Screen and
Ground, “Id” = Fault current between Conductor and Screen)
2.2.2.3
– Voltage input
The relay monitors the A.C. test voltage applied by the Main Injection Unit to the D.C. systems
under supervision. This voltage is also used as reference for measuring the Power Factor of the
injected current flowing through a fault as well as through the capacitance to earth of the D.C.
cables. The value of the Power Factor allows to discriminate between the Fault Current
(Resistive) and the normal leakage current (Capacitive).
2.2.2.4
– Earth Fault Resistance
Measurement range (2000
20000)
.
The relay measures the resistive component of the earth current and computes the fault
resistance of the two supervised circuits:
int
_
cos
R
s
I
V
RGs
s
int
_
cos
R
d
I
V
RGd
d
“V”
=
RMS value of voltage measured on
terminals 10-11.
“cos
s”
=
“V^Is” phase displacement
“Is”
=
RMS value of fault current shield to gnd.
“cos
d”
=
“V^Id” phase displacement
“Id”
=
RMS value of fault current cable to shield.
“R_int”
= Internal Resistance of MSG-2044
Where "R_int" is the internal resistance of MSG (normally 160
).
On the
Display the measurements of “cos
s” and “cos
d” are also available.
For angle “
s” and “
d” > 90°, the display show “cos = 0”.
