selections and settings intended for use are verified. If one chooses to reduce some
time settings in order to speed up verification, be careful to set the parameters at
intended operational values at the end of the verification procedure. One such
parameter is the
tReclaim
time and could result in a long delay of reclosing shots,
for example, shot 2 and later ones.
The verification test is performed together with protection and trip functions.
Figure
illustrates a suggested testing arrangement, where the circuit-breaker
(CB) is simulated by an external bi-stable relay (BR), for example a relay type
RXMVB2 or RXMD or Breaker Simulator of ABB. The following manual
switches are used:
•
Switch or push-button to close (SC)
•
Switch or push-button to trip (ST)
•
Switch for CB ready condition (SRY)
If no bi-stable relay or breaker simulator is available, replace it with two self-reset
auxiliary relays and use a self-holding connection.
Use a secondary injection IED test set to operate the protection function. The test
set shall be switched off when a trip signal is given or when the BR comes to open
position to simulate real conditions.
The CB simulation can be made more elaborate, including simulation of the
operating gear condition, CBREADY of either the type ready for a Close-Open
(CO) cycle, or the type ready for an Open-Close -Open (OCO) cycle.
The CB condition CBREADY of a type, CO, shall be high (true) until a closing
operation is performed. It then goes low (false) for a recharging time of about 5 -
10s. After that it is high again.
A CB condition CBREADY of a type, OCO shall be high (true) before and during
tripping (Start reclosing). During tripping it goes low for a recharging time, for
example, 10s. It may thus be low at the instant of reclosing. After each Open or
Close operation it may need a recharging period before it goes high again.
In the example of CB simulation arrangement, the CBREADY condition is
simulated by a manual switch, SRY.
Information and material for the verification:
•
Protection or control unit, IED, configured and with settings entered.
•
Configuration diagram for the IED
•
Terminal diagram for the IED, or plant circuit diagram including the IED
•
Technical reference manual for the IED
•
IED test set for secondary injection
•
Means to indicate, measure and record operation and times, for example an
event recording facility
1MRK 511 248-UEN -
Section 6
Testing functionality
79
Commissioning Manual
