Alstom SHPM 101 - Section 4. MODULE DESCRIPTIONS; 4.7 Zone 1;Zone 2 module RRM 08; 4.7.1 Setting board (ZH0732)

SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Page 8 of 74
The respective output voltages are:
50Hz:
–
I
A
ZPh =
K1+K2
x (
I
A
1 – I
A
2) x 0.9848
/–10
°
5
+
I
N
ZN = [(K5 + K6) x (I
N
1 – I
N
2) +
K4
x (
I
N
3 – I
N
COM)] x 0.98480 /–10°
5
I
A
R' = (I
A
R – I
A
R COM) x 0.9781 /–13°
60 Hz:
–I
A
ZPh =
K1 + K2
x (I
A
1 – I
A
2) x 0.9781 /–12°
5
+
I
N
ZN = [(K5 + K6) x (I
N
1 – I
N
2) + K4 (I
N
3 – I
N
COM)] x 0.9781 /–12°
5
I
A
R' = (I
A
R. – I
A
R COM) x 0.9636 /–15.5
0
Note: Phases B and C output voltages are derived similarly
Relay facia Function Range covered
switch reference by switch
K1 Coarse Z
Ph
0 to 4 in steps of 1
K2 Fine Z
Ph
0 to 0.8 in steps of 0.2
K3 R
S
8, 16, 32, 40 and 48
K4 Coarse Z
N
0 to 4 in steps of 1
KS Fine Z
N
0 to 0.9 in steps of 0.1
K6 Very fine Z
N
0 to 0.08 in steps of .02
Table 1: Phase and neutral module switch functions
4.7 Zone 1/Zone 2 module RRM 08
Introduction
This is a two board module which contains the reach settings, the polarising
circuits and the comparators for Zone 1 (Z1), Zone 1 extension (Z1X) and Zone 2
(Z2).
The phase fault elements have shaped mho characteristics. The ground fault
elements can be either shaped mho or quadrilateral. This module is power system
frequency dependent and is available in either 50 or 60Hz versions.
The nameplates are shown in Figure 17.
4.7.1 Setting board (ZH0732)
The right hand board contains the fine reach settings for Z1, Z1X and Z2.
The settings are obtained by attenuating each of the phase-neutral voltages with
switches and resistor networks. A block diagram is shown in Figure 12.
The switches for each of the three phases are ganged together. The switches
labelled K11, K12, K13 and K14 set the Z1 reach. K21, K22 and K24 set the Z2
reach. The Z1X reach, which is a multiple of Z1, is controlled by K15.
An analogue switch, controlled by the scheme logic, is used to select the voltage
from Z1 or Z1X as appropriate. The attenuated voltages are mixed with the
appropriate
IZ signals (from the phase and neutral module). The resultant IZ