Alstom SHPM 101 - Section 6. TECHNICAL DATA; 6.1 Input ratings; 6.2 Impedance setting ranges

SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Page 66 of 74
Section 6. TECHNICAL DATA
6.1 Input ratings
AC voltage V
n
100 to 120 volts rms phase-phase. The relay will withstand
150% rated voltage continuously, or 250% rated voltage for
10s.
AC current
I
n
1A or 5A rms per phase. The relay will withstand 2.4 times
rated current continuously and 100A for 1s (1A version) or
400A for 1s (5A version).
Frequency f
n
50Hz or 60Hz.
6.2 Impedance setting ranges
The range of Zone 1, Zone 2 and Zone 3 forward if 0.2Ω to approximately 240Ω
on a 1A relay, or 0.04Ω to approximately 48Ω on a 5A relay. The reverse reach
of Zone 3 has the same maximum setting, but a minimum of 0.05Ω (1A relay) or
0.01Ω (5A relay). These settings are achieved as follows:
Z
Ph
Coarse reach setting common to all zones
0.1 to 4.8Ω in 0.2Ω steps (1A)
0.04 to 0.96Ω in 0.04Ω steps (5A)
Z
N
residual compensation setting
0.2 to 5.98Ω in 0.02Ω steps (1A)
0.004 to 1.196Ω in 0.004Ω steps (5A)
Fine settings as multiples of coarse setting
Zone 1 – 1 to 9.98 in 0.02 steps
Multiplied by 1 or 5
Zone 2 – 1 to 9.9 in 0.1 steps
Zone 3 – 1 to 9.9 in 0.1 steps
Multiplied by
Zone 3 reverse – 1 to 9.9 to 0.1 steps 1 or 5
multiplied by 0.25, 0.5 or 1
Fine setting of Extended Zone 1 as multiple of normal Zone 1
1 to 2 in 0.1 steps
Switched attenuators are used for all relay reach settings. Each switch is labelled
as a K-factor for identification. K1, 2, 4, 5 and 6 are attenuators of the
IZ
(operating) signal whereas all othe K-factors are attenuators of the V (restraint)
signal.
The reach is calculated as follows:
Coarse reach Z
Ph
=
K1 + K2 θ
Ph
°
I
n
Residual compensation Z
N
=
Z4 + K5 + K6
I
n
θ
N
°
where I
n
is the nominal current rating of the current input module.
Residual compensation factor =
Z
L0
+ Z
L1
3Z
L1
=
Z
N
Z
Ph