Alstom SHPM 101, Service Manual

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SERVICE MANUAL R5888C
QUADRAMHO Chapter 5
Page 20 of 24
5.4.8 Weak infeed feature
If this is to be used SW8 should now be moved to the right.
If it is also to be used to give a direct 3 phase aided trip, SW7 will also be set to
the right later.
If SW7 is set to the left, a weak infeed echo feature only will be available to
enable fast end zone clearances at the strong infeed end.
i) Check on weak infeed echo feature
The normal echo feature is not enabled when the breaker at the weak infeed
end is closed. Thus make sure the breaker open opto isolator input is not
energised.
Commence with SW7 set to the left.
No ac volts should be supplied to the relay.
There is a 10ms delay on the echo once the signal receive opto isolator is
energised. To check this, start a timer from a double pole switch energising
terminals A9(+) to A10 and stop the timer from a signal send contact (B1–B2 or
B3–B4). The time measured should be 15 – 20ms.
Check that no signal send occurs if normal 3 phase volts are applied to the
relay. Remove the volts.
Measure the dwell time of the signal send contact when closing the two pole
switch; 105 – 115ms should be obtained.
Check the normal echo feature is not enabled when the miniature circuit breaker
(mcb) opto coupler (case terminals A1/A2).
ii) Weak infeed three phase tripping
These test need only be carried out if tripping is required.
The logic contains a delay on tripping of 60ms and a delay on drop-off of the
signal receive of 100ms.
Move SW7 to the right if tripping is required. To check the 60ms timer:
With no ac volts on the relay, connect a double pole switch to start a timer and
to energise the signal receive opto isolator input (A9+ to A10). Connect the any
trip contact on the 1Z test plug terminals 7 and 8 to stop the timer; the time
measured should be 65 – 75ms. Aided trip indication should be obtained and
3 phase trips given.
Check that no trip is given if normal 3 phase ac volts are present.
To check the 100ms timer:
With no ac volts on the relay, connect the timer so that it will start on switch off
of the signal receive input and stop when the any trip contact opens.
The time measured should be 105 – 115ms.
Check the aided trip indication and 3 phase trip is blocked when the miniature
circuit breaker (mcb) opto coupler (case terminals A1/A2).
5.5 Signalling channel check (schemes 02 to 07)
This test should be applied to any scheme using a signalling channel when the
channel is available and in service.