Chapter 21 - Commissioning Instructions
These product checks are designed to ensure that the device has not been physically damaged prior to
commissioning, is functioning correctly and that all input quantity measurements are within the stated tolerances.
If the application-specific settings have been applied to the IED prior to commissioning, you should make a copy of
the settings. This will allow you to restore them at a later date if necessary. This can be done by:
Obtaining a setting file from the customer.
Extracting the settings from the IED itself, using a portable PC with appropriate setting software.
If the customer has changed the password that prevents unauthorised changes to some of the settings, either the
revised password should be provided, or the original password restored before testing.
If the password has been lost, a recovery password can be obtained from General Electric.
PRODUCT CHECKS WITH THE IED DE-ENERGISED
The following group of tests should be carried out without the auxiliary supply being
applied to the IED and, if applicable, with the trip circuit isolated.
The current and voltage transformer connections must be isolated from the IED for these checks. If a P991 test
block is provided, the required isolation can be achieved by inserting test plug type P992. This open circuits all
wiring routed through the test block.
Before inserting the test plug, you should check the scheme diagram to ensure that this will not cause damage or
a safety hazard (the test block may, for example, be associated with protection current transformer circuits). The
sockets in the test plug, which correspond to the current transformer secondary windings, must be linked before
the test plug is inserted into the test block.
Never open-circuit the secondary circuit of a current transformer since the high
voltage produced may be lethal and could damage insulation.
If a test block is not provided, the voltage transformer supply to the IED should be isolated by means of the panel
links or connecting blocks. The line current transformers should be short-circuited and disconnected from the IED
terminals. Where means of isolating the auxiliary supply and trip circuit (for example isolation links, fuses and MCB)
are provided, these should be used. If this is not possible, the wiring to these circuits must be disconnected and the
exposed ends suitably terminated to prevent them from being a safety hazard.