SERVICE MANUAL R5888C
QUADRAMHO Chapter 5
Page 5 of 24
d) The detection of pole dead.
e) The weak infeed feature.
Select test option 43 (W = 4, Y = 3) all the LEDs now have a different function
from that on the nameplate. Apply volts in turn to each voltage input and check
that the LED indicated lights when 49 volts is applied and does not when 40
volts is applied. If preferred the precise pick-up can be determined and the
drop-off should be within 10% of that value.
Level detector Terminals injected LED marking
A phase 1Z 1–4 A
B phase 1Z 2–4 B
C phase 1Z 3–4 C
Note: During test option checks, only the LEDs mentioned are of concern in a
particular test, others may be on and can be ignored; however, a full table
is given in Figure 3.
4.4.2 Fixed current level detector checks
(i) Low set current level detectors
Each phase current is monitored and the setting is changed by the value of K1
and K2 selected on module 1, the most sensitive setting is 5%
I
n
.
Current setting =
5
x
4.8
x I
n
amps (±10%)
100 K1 + K2
I
n
= relay rated current
The scheme logic uses the information in:
a) Gating the comparators to limit the system impedance ratio up to which the
relay functions.
b) The switch-on-to-fault feature.
c) The detection of pole dead.
Keep test option 43 selected and inject current into each pair of phase
terminals, on the left hand side of the 1Y test block, in turn. Determine the pick-
up as indicated below, the drop-off should be within 10% of actual pick-up.
Level detector Terminals injected LED marking
A phase 1Y 1–2 Z3
B phase 1Y 3–4 Aided trip
C phase 1Y 5–6 SOFT
Note: Refer to 4.4.3(i) as it is convenient to combine the tests.
(ii) High set current level detectors
These are only used in the blocking scheme or the weak infeed feature which
can be used in conjunction with the permissive overreach scheme.
If these schemes are not to be used or are not likely to be selected in the future
this test need not be done.
Current setting =
12.1
x
4.8
x I
n
amps (±10%)
100 K1 + K2
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