Siemens 7UT51 User Manual

16 Bench Testing
7UT51 v3
172 PRIM-2330C
16.6.1 Testing the High
-
Set
Overcurrent Stage
Testing can be performed with single-phase,
two-phase or three-phase test current. When
assessing the currents, it must be considered that the
current that is evaluated by the relay is referred to the
rated current of the protected object or transformer
winding.
For testing the 50HS stages, therefore, measurement
shall be performed dynamically. It should be noted that
the relay picks up at 1.1 times the setting value and
does not at 0.9 times setting value.
When the test current is injected, the pickup indication
of the 50HS stage, annunciation “
Backup 50HS
”,
appears. After expiration of the time delay, trip signal
is given (LED 4 at deliver and annunciation “
Back
Gen. Trip
”). If the protection is switched
On
, the
assigned trip contacts close.
It must be noted that the set times are pure delay
times, operating times of the measurement functions
are not included.
16.6.2 Testing the Definite Time
Overcurrent Stage
For the test, the
Definite Time
mode must be selected
in Address 2111.
The rated object current is to be considered.
When the set value for 50T (Address 2112) is
exceeded, the pickup indication “
Backup I>/Ip
”
appears.
After the expiration of the time delay in Address 2113,
trip signal is given (LED 4 and annunciation “Back
Gen. Trip”). If the protection is switched
On
, then the
assigned trip contacts close.
It must be noted that the set times are pure delay
times, operating times of the measurement functions
are not included.
16.6.3 Testing the Inverse Time
Overcurrent Stage
For these tests, one of the
Inverse Time
modes must
be selected in Address 2111.
The rated object current is to be considered.
When the test current is increased above 1.1 times the
set value 51PU (Address 2114), pickup indication
appears (“
Backup I>/Ip
”).
The time delay depends on which characteristic has
been selected in Address 2111 and the set time
multiplier in Address 2115. The expected time delays
can be calculated or read from the characteristic
curves.
Be certain to consider current matching
factors.
Test currents larger than four (4) times In
or 15A (Sensitive input) may overload
and damage the relay if applied
continuously.
Observe a cooling down period!
Test currents larger than four (4) time In
or 15A (Sensitive input) may overload
and damage the relay if applied
continuously.
Observe a cooling down period!

Siemens 7UT51 Specifications

General

Brand	Siemens
Model	7UT51
Category	Relays
Language	English