Section 1: Pilot Wire Current Differential Scheme; General; Information Required When Ordering - Siemens Solkor 7PG2113 Technical Manual

Section 1: Pilot Wire Current Differential Scheme

1.1 General

The 7PG2113 and 7PG2114 relays provide both pilot wire current differential protection and overcurrent and earth
fault protection as well as other additional functions. The 7PG2115 and 7PG2116 additionally provide directional
functionality for the overcurrent and earth fault protection. The Overcurrent and earth fault functions are typically
configured to provide an Overcurrent and Earth fault Guard function and can also provide backup protection for
the current differential function.
The current differential trip contacts can be connected in series with the contacts of an Overcurrent Guard relay to
avoid operation for damaged pilots during normal levels of load current. The 7PG2113, 7PG2114, 7PG2115 and
7PG2116 relays provide both the Pilot Wire differential protection and the Guard function as well as other
additional protection functions.
Additional external Pilot Supervision equipment can be supplied to detect pilot cable open circuit which can lead
to protection operation.
Solkor R and Solkor Rf are well established pilot wire feeder differential protections operating on the current
balance principle and are suitable for application on privately owned 2 core pilots with loop resistance up to
2000ohms to protect 2 ended feeder circuits up to 20km in length. Two identical relays are used as a pair with
one relay connected to current transformers at each end of the feeder respectively.
The relay has an insulation level of 5kV between pilot connections and the local ground to withstand voltages
induced on the pilot cable due to coupling with the fault current flowing in a parallel path and to withstand
differential ground voltages caused by the flow of fault current. This is generally adequate for distribution feeders
but for higher voltage systems where feeders may be longer and fault levels higher, an additional external
isolation transformer is available for use with the relay in Rf mode to increase the voltage withstand to 15kV. One
transformer should be fitted at each end of the pilot connection.
The R/Rf relay is primarily intended for use in the Rf mode which has the advantage of increased operating speed
but can be simply changed to R mode for compatibility with pre-installed remote end relays which are older 5kv
Solkor R type relays. The 7PG2113/4/5/6 Solkor relays and 7PG2111 Solkor R/Rf relays are not compatible with
the older 15kv Solkor R system, Solkor A or Solkor B.

1.2 Information required when ordering

7PG2113/4/5/6 Protection relay
External Pilot Supervision devices
Intertripping
©2010 Siemens Protection Devices Limited
CT secondary Current Rating
Insulation level (5/15kV)
Set as R or Rf mode
Non Directional / Directional Overcurrent & Earth Fault
Auxiliary DC supply
Binary Input/Output requirements
Case Styles
System Frequency (50/60Hz) (used for B22 relay setting)
Send or Receive End
Insulation level (5/15kV)
Auxiliary DC supply
Intertripping is not compatible with 7PG2113/4/5/6 used as Guard Relays
7PG2113/4/5/6 Solkor Applications Guide
Chapter 7 Page 4 of 49