SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Page 12 of 74
4.9.2 Scheme logic settings and indications
An illustration of the frontplate layout is shown in Figure 26.
4.9.3 Indications
The scheme logic provides nine indications, the function of each indication is
described below:
Indication name plate legend Function of indication
A Fault involving “A” phase
B Fault involving “B” phase
C Fault involving “C” phase
Z2 Zone 2 time delayed trip
Z3 Zone 3 time delayed trip
AIDED TRIP Signal aided trip (PUR, POR or BLOCK)
SOTF Line is energised on to a fault
V~ FAIL Fuse failure condition
POWER SWING Power swing condition
4.9.4 Code switches
The code switches allow selection of the five standard schemes with associated
tripping modes and also the test options (See Section 5.16.22 and 4.9.46
respectively).
The left hand code switch is labelled X while the right hand switch is labelled Y.
4.9.5 Switch banks
The top switch bank t
Z2
(see Figure 26) is used to set the Zone 2 time delayed trip
time. The timer has a range of 0 to 250ms in increments of 10ms. The timer is set
by moving the required switches to the right hand position. The total time is the
summation of the individual switches.
The second switch bank t
Z3
is used to set the Zone 3 time delayed trip time
The timer has a range from 0 to 580ms in increments of 40ms. The timer also has
an infinity position which is selectable via the top switch. Setting of the timer is
similar to the Zone 2 timer.
The third switch bank (t
p
and t
d
) is used to set the tp and td current reversal guard
timers. The top four switches correspond to t
p
while the lower four switches
correspond to t
d
. Both t
p
and t
d
can be set in the range 0 to 90ms in increments of
6ms. Setting of the timers is similar to Zone 2 timer
The fourth switch bank contains the minor options that are available (see Table 2).
The switch bank at the top right hand side of the module is used for the power
swing blocking circuitry. The top three switches are used to block Zones 1, 2 and
3 individually. Blocking is performed with the switches in the right hand positions.
The bottom switch, SW9, is used to select the PSB option when in the right hand
position.
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