The Forward/Reverse direction of power is defined by the Export Power/Lag Var convention setting
in the Configuration Device menu. For real power, set phase current in phase with phase-neutral
voltage on all phases for forward direction and to 180° for reverse for a +ve convention setting. For reactive
power, set phase current to lag phase-neutral voltage by 90° for forward direction and current to lead voltage
by 90° for reverse direction for a +ve convention setting. Non-directional real or reactive power elements will
operate for both forward and reverse direction. Apparent power elements will operate for power which is
independent of the phase angle between voltage and current. If the 32-n Delay setting is long it will be
advantageous to map the function to temporarily drive the relevant pickup output in the Pickup Config
sub-menu in the Output Config menu as this will allow the Pickup led to operate for the function. If the
delay setting is short the operation of the element can be easily checked directly.
The current or voltage should then be decreased/increased until the element resets.
If the element is set to have a UC Guard applied, the applied current must be above the 32-n UC Guard
Setting. Apply setting power +10 % for over-power or -10 % for under-power and record operating time.
Power (⋅
S
rated
)
U/O DTL (sec) P.U.
Power (⋅
S
rated
)
D.O.
Power (⋅
S
rated
)
Op. Time
± 0.5 Hz
UC Guard Notes
32-1
32-2
If the element is set with UC Guard, the setting can be tested by applying the test current at a level below the
32-n UC Guard Setting at a power in the operate range. Increase the current until the relay operates.
UCG UCG Setting (⋅
I
rated
)
Power Element
Used for Test
Blocked Current
(D.O.)
Unblocked
Current (P.U.)
Notes
U/O Power
Element Blocking
The U/O power elements can be blocked by Binary Input Inhibit or operation of VTS. This functionality
should be checked.
Element
BI Inhibits VTS Inhibit
32-1
32-2
Check correct indication, trip output, alarm contacts, waveform record.
When testing is complete reinstate any of the disabled functions.
37 Undercurrent Protection – Phase
If 2 undercurrent 37 elements are used with different settings, it is convenient to test the element with the
lowest setting first. The higher setting element can then be tested without interference from the other
element.
Apply 3 phase balanced current at a level above the undercurrent 37-n setting until the element resets.
Reduce single phase current to below setting to prove the operation of the Pickup Option Any/All
setting.
If DTL setting is small, gradually reduce single phase current or 3 phase currents until element operates.
If DTL is large apply 1.1 times setting, check for no operation, apply 0.9 times setting, check operation.
Testing of this element phase by phase may cause inadvertent operation of the 46 NPS overcurrent elements.
Apply 0.5 times setting current and record operating time.
9.9.5
Functional Tests
9.9 Protection Functional Tests
468 Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019
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