Alstom SHPM 101, Service Manual

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SERVICE MANUAL R5888C
QUADRAMHO Chapter 5
Page 22 of 24
Connect A–N volts (1Z 1–4 red terminals) to a phase angle meter voltage input
terminals, giving careful attention to polarity.
Use another test plug to connect the phase angle meter current terminals in series
with the A phase current.
Before inserting the 1Y test plug link through 2, 3, 4, 5, 6, 7 and 8. Connect the
red 1Y1 terminal to the phase angle meter current input terminal (the polarity
indication should correspond to that used for the A voltage input) and complete the
current path from the phase meter to the relay side of the 1Y1 test plug.
The test plug can now be inserted in the 1Y position (the lower rack).
Check that the angle measured gives reasonable agreement with the known load
power factor.
This procedure must be repeated on another phase.
Remove the 1Y test plug.
Connect the phase meter current inputs to the 1Y3 terminals. Link through the 1Y1
terminals. Move the one voltage input wire for the phase angle meter from the red
1Z1 test plug terminal to the red 1Z2 terminal.
Insert the 1Y test plug and check that the measured phase angle again gives
reasonable agreement with the known load power factor.
If these tests are satisfactory, terminals 1 to 6 inclusive of the 1Z test plug can be
linked through.
As the 1Z10 terminals are not linked, trips will not occur for the next test, also the
relay available LED will not be illuminated.
6.4.3 Directional check
i) The test must be carried out with the relay energised from the line voltage
transformers and current transformers with the load current above the level
detector setting and preferably at a lagging power factor in the tripping
direction.
Test option 43 can be used to determine which low set current level detectors
are picked up. No comparator can operate unless the appropriate low set
phase current level detectors are picked up. These level detectors are most
sensitive when K1 + K2 = 4.8, thus a temporary change in setting might help.
ii) To perform the directional check, the restraint voltage has to be removed from
the measuring circuits of Zone 1. This is achieved by rotating K11 to the
∞
position
An instantaneous Zone 1 trip on all three phases will be indicated if the relay is
looking in the correct direction and the load angle falls within the straight line
directional characteristic passing through the origin and covering approximately
90
°
either side of the relay characteristic angle.
The ideal conditions for the load are shown in Figure 11A. The operating
region is most easily determined by drawing in the RCA leading the load
current by ØPh and then drawing the boundary lines at 90
°
to the RCA.
Any voltage vector which falls within the 180
°
operation area, if injected into
the relay V
A
input will give operation. This is illustrated in Figure 11B where
injecting V
B
from the line into the relay V
A
input, etc, will give operation (see
Figure 9C).