Checking The Rtxp Test Switch - ABB ret650 Commissioning Manual

1MRK 504 126-UEN -
3.9
Commissioning Manual
Test the circuitry.
• Polarity check
• VT circuit voltage measurement (primary injection test)
• Earthing check
• Phase relationship
• Insulation resistance check
The polarity check verifies the integrity of circuits and the phase relationships. The
check must be performed as close to the IED as possible.
The primary injection test verifies the VT ratio and the wiring all the way from the
primary system to the IED. Injection must be performed for each phase-to-neutral
circuit and each phase-to-phase pair. In each case, voltages in all phases and
neutral are measured.

Checking the RTXP test switch

The RTXP test switch is designed to provide the means of safe testing of the IED.
This is achieved by the electromechanical design of the test switch and test plug
handle. When the test plug handle is inserted, it first blocks the trip and alarm
circuits then it short circuits the CT secondary circuit and opens the VT secondary
circuits making the IED available for secondary injection.
When pulled out, the test handle is mechanically stopped in half withdrawn
position. In this position, the current and voltage enter the protection, but the alarm
and trip circuits are still isolated. Before removing the test handle, check that no
trip or alarms are present in the IED.
Not until the test handle is completely removed, the trip and alarm circuits are
restored for operation.
By pulling in all cables, verify that the contact sockets have been
crimped correctly and that they are fully inserted. Never do this
with current circuits in service.
Current circuit
1. Verify that the contacts are of current circuit type.
2. Verify that the short circuit jumpers are located in the correct slots.
Voltage circuit
Section 3
Starting up
27