Siemens 7SA511 manual Reverse Interlocking, Teleprotec Pott Mode, Overreach Pilot Wire Comp

7SA511 Line Protection Relay Chapter 7

Prerequisite Settings:

Addr. LCD Text

7804 TELEPROTEC.

2201 POTT MODE

2202 POTT MODE

Description

Type of pilot protection scheme

Turn the POTT protection scheme on and off

Mode of operation for permis- sive overreach transfer scheme

Setting

OVERREACH

ON

PILOT WIRE COMP.

Test Procedure

1.Simulate a short circuit beyond Z1 but within overreach zone Z1B. Because of the absence of the receive signal, the relay first trips in one of the upper zones (normally T2). Perform this test from both line ends.

2.Turn on the DC voltage for the fail-safe loop. The additional relays for pilot protection must be in operation. The loop now carries monitoring current, and the additional relays at both line ends are energized.

3.Simulate a short circuit at one line end beyond the first zone but within the overreach zone Z1B. Tripping occurs instantaneously or after T1B (when a delay is set). Perform this test also at both line ends.

Since the DC monitor is an essential part of the pilot wire system, this test has simultaneously proved that the pilot wires are functioning correctly; therefore, all other tests described in section 7.3.3 can be skipped.

Reverse Interlocking

The test procedure in this section checks the reverse interlocking pilot protection method. Skip this section if a different pilot protection method other than reverse interlocking is used.

The protection relay on the incoming feeder and those on all outgoing circuits must be in operation. At first the auxiliary voltage for reverse interlocking should not be switched on.

Prerequisite Settings

Addr. LCD Text

7804 TELEPROTEC.

2201 POTT MODE

2202 POTT MODE

Description

Type of pilot protection scheme

Turn the permissive overreach transfer scheme on and off

Mode of operation for permis- sive overreach transfer scheme

Setting

OVERREACH

ON

REVERS INTERLOCK

Test Procedure

1.Simulate a short circuit within zone Z1 and within the overreach zone Z1B. Because of the absence of the receive signal, the relay trips in the (delayed) time T1B.

July 27, 1995 7-9