4 4
S V E R K E R 7 5 0 / 7 6 0
P r o g r a m m a E l e c t r i c A B
Z P - C D 0 1 E R 0 5 A
6.8 Measuring
operating times for
over (current/
voltage/other entity)
relays
Method 1: Normal injection
Generation continues until the protective relay
equipment operates.
1
Initial setting: OFF, HOLD, Main knob at 0.
2.
Connect the relay current input and tripping
output to Sverker.
3.
Use the button marked A to transfer the
ammeter test point to the selected output.
4.
Set the timer start condition to INT.
5.
Set the timer stop condition (to CLOSURE
+ OPENING, CONTACT for example).
6.
Activate ON using the start switch. Set the
desired current for measuring the operating
time. This current must be set well above
the operating limit.
7.
Interrupt output by setting the start switch
to OFF.
8.
Activate ON+TIME using the start switch.
9.
Read and note the time and current.
Method 2: Manually-controlled
(momentary) injection
This is useful when you want to eliminate overheat-
ing in the relay. Generation continues only as long
as the start switch is kept at the ON position.
1.
Initial settings: OFF. MOMENTARY (see
explanation of settings in Chapter 5).
HOLD. Main knob at 0.
2.
Connect the relay’s current input and
tripping output to Sverker.
3.
Use the button marked A to transfer the
ammeter test point to the output that is
being used.
4.
Set the timer start condition to INT.
5.
Set the timer stop condition (to CLOSURE
+ OPENING, CONTACT for example).
6.
Set the desired current (it must exceed the
pick-up value by an ample margin) by
changing the setting of the main knob.
Activate ON briefly using the start switch
and read the current from the ammeter.
Repeat until the desired current has been
set.
7.
Activate ON+TIME using the start switch
and keep it activated until tripping occurs.
8.
Read and note the time and current.
Method 3: Time-limited injection
Time-limited generation, as its name implies,
interrupts output after a preset time. This is useful
when you want to prevent overheating in the
protective relay equipment.
1.
Initial settings: OFF. MAX TIME (see expla-
nation of settings in Chapter 5.) HOLD.
Main knob at 0. The maximum time must
be set longer than the operating time of
the instantaneous unit.
2.
Connect the relay current input and tripping
output to Sverker.
3.
Set the ammeter to measure current at the
current output that is being used.
4.
Set the timer start condition to INT.
5.
Set the timer stop condition (to CLOSURE
+ OPENING, CONTACT for example).
6.
Change the main knob setting.
7.
Activate ON+TIME using the start switch.
8.
Check to see that the instantaneous unit
has operated. This can be done by a)
checking the indicator lamp on the relay or
b) checking to see that the TRIP indicator
lamp on Sverker is on.
9.
Read and note the time and current.
10. Search for the lowest current where the
relay operates, by repeating from point 6
above and onwards.
Summary of Contents for Programma Sverker 750
Page 1: ...SVERKER 750 760 User s manual Relay Test Unit ...
Page 28: ...2 9 S V E R K E R 7 5 0 7 6 0 P r o g r a m m a E l e c t r i c A B Z P C D 0 1 E R 0 5 A ...
Page 75: ...7 6 S V E R K E R 7 5 0 7 6 0 P r o g r a m m a E l e c t r i c A B Z P C D 0 1 E R 0 5 A ...
Page 76: ...Subject to change without notice Printed matter ZP CD01E R05B 2007 ...