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  MORE than a supplier     HV Power Customer Newsletter October 2018    
        SCADA cards for REG-D and REG-DA have changed    

    In this issue:

Photo - Warwick Beech


Protocol = Human

Working with protocols like IEC 61850 is a joy. Everything is all defined (almost), and the purpose of the node is (almost) clear. However, the human protocol does not work like that. We use different words to mean the same thing, and just to confuse things more, the same word can mean different things (homographs). In this newsletter I cover some Line Differential terminology that you may encounter when looking at Siemens and others documentation. With the merging of Reyrolle into Siemens, you might find some different terms in the Reyrolle documentation to that of Siemens.

Hopefully this will give you the protocol map to understand the definition, plus a reminder in our industry it’s wise to confirm and ask “by stating this, I assume you mean that”. (But remember to err is human, to really foul things up requires a computer!)


Warwick Beech



This is an update to the lead item of last month’s newsletter. I have added confirmation that serial protocol capability is still provided in the new PEDSV, and just so there are no surprises, mentioned the removal of COM1 DB9 connector.

After 15 years in production, component availability is forcing the early retirement of A.Eberle’s REG-PED SCADA cards that are used in REG-D, REG-DA voltage regulators and similar products.

NOTE: There are no changes in the supply of REG-D and REG-DA themselves.

A new series of cards providing enhanced cyber-security, which have been in development, are now being released to take over from the REG-PED.

The new REG-PEDSV (SV = Sampled Values) is a pin-compatible replacement to the REG-PED. As standard, the REG-PEDSV offers two Ethernet ports, but can be optionally fitted with an additional retrofitable module providing a further two Ethernet ports – for gathering sampled measured values from IEC 61850-9-2 process bus environments. The REG-PEDSV features an on-board pluggable micro-SD-card, which can be loaded with new firmware and the card jumpered to firmware update on reboot. The micro-SD-card can also be used for storing of logging data (or even manuals), with its contents accessible via the new front-panel USB interface (micro B type).

The RJ45 copper Ethernet interfaces are 10/100/1000 Mbit rated. Where equipped with fibre optic interfaces for Ethernet Ports 1 & 2, these are 100/1000 Mbit software selectable, allowing use on gigabit systems. Fibre optic ports 3 & 4 need to be specified at order as either 100 or 1000 Mbits.

The PEDSV card still offers serial COM1/2/3 interfaces, so COM1 or COM3 can be used for serial protocol, or for remote engineering connection to the 'REG-D'. The appropriate wiring out of the desired interfaces must be specified in the design drawings. The REG-PED did feature a DB-9 connector on the rear of the card, which provided another method to access to COM1 interface (but COM1 interface was often wired out to the rear enclosure screw terminals to connect to via there). In the REG-PEDSV, the DB-9 is removed (to make way for optional Ethernet ports 3&4) – but a COM1 connection can still be made via wiring to the rear enclosure terminals etc.

The new REG-PEDSV card will:

  • Require WinConfig version 13.1 (or later) to be used to load SCADA settings
  • Offer LC connectors only where fibre is specified (optional 1m LC-to-ST fibre adaptor cable can be made available if required)
  • Need a new rear cut-out if a REG-PEDSV as the cut-out provided at the back of a new relay with a REG-PEDSV is a slightly different shape to its predecessor

A version of the REG-PEDSV is available for the REG-DA which offers the same features as that described for the REG-D. However, this requires one more expansion slot than the existing REG-PED. Therefore, it does not allow (for example) 2 x PT100 inputs to be fitted.

Where customers want to retain access to the two 'spare' slots in the REG-DA, a new REG-PE card is available. The new REG-PE features two Ethernet interfaces, so from our point of view, it’s the logical alternative for the existing REG-DA ‘PED’.

The new REG-PE (with two Ethernet ports) will:

  • Only require two slots, leaving two free (like the old REG-PED SCADA card)
  • Have two Ethernet ports with choice of 2 x Cu, 1 x CU + 1 x FO or 2 x FO interfaces. The FO interfaces can be ST or LC type
  • Provide acess to DNP (serial) or MODBUS RTU protocols via inbuilt serial interface
  • Require WinConfig version 13.1 (or later) to be used to load SCADA settings

Old PED cards are no longer available, so supply of REG-PEDSV and new REG-PE cards are being expedited. We will contact customers shortly where this needs to occur for an existing order. We’re expecting there might be a few technical questions, so remind you that the quickest route to support is by contacting our Service Support team on 0800 HV CALL.

You do not need to update the REG-D/DA firmware to use the new SCADA protocol cards, but must use new SCADA protocol software WinConfig 13.1 or later.


Example of REG-PEDSV SCADA card for REG-D.


      Intertrip, Transfer trip, Direct Transfer trip and Remote trip for Line Diff relays    

What’s the difference between Intertrip and Remote trip?

Most often, Line Differential relays will cause trip at both ends, but this is not always the case – such as where an overcurrent check is used (i.e. single end feed to in-zone fault). The ‘Intertrip’ function is used to ensure that a trip of the remote end occurs.

Remote (or Transfer trip) is typically used to send a trip from outside the protection zone to the remote end – such as a signal from an incomer circuit breaker fail scheme. Transfer tripping is only used from one end/direction (that is the system is set such that a 'remote trip' signal to one end is 'transferred' by the pilot wire to the other end relay). At the remote end relay, there is no differentiation in performance between Intertrip and Remote/Transfer trip. Both have the same effect of tripping the local breaker.

However, it’s always wise to confirm the functionality being requested/specified, as the term 'Intertrip' is used in only some relays with a distinction of internal-intertrip and external-intertrip.


      A choice of three Siemens entry-level Line Differential Relays    

The Solkor-N numerical Line Differential relay is no longer being promoted. The Siemens Argus ‘7SR18 Solkor’ now takes its place, and is a very logic fit between the very popular Solkor R/Rf and the 7SD80 series.

7SR18 Solkor
Solkor R/RF, 7SR18 Solkor & SIPROTEC Compact 7SD80.

Solkor R/Rf:

  • Ultra-reliable line differential scheme for circuits with copper pilot wires
  • No Aux power required for relay operation
  • Simple setting by one padding resistor arrangement to adjust for pilot wire resistance

7SR18 Solkor:

  • Supports fibre optic pilots
  • Wide-range power supply (24-250 Vdc, 100-230 Vac)
  • Simple (and free) Reydisp setting software
  • 3 or 6 binary inputs
  • DNP serial or IP protocol and IEC 61850 supported
  • Intertrip and remote trip
  • Overcurrent guard and backup overcurrent

SIPROTEC Compact 7SD80:

  • Supports fibre optic and/or copper pilots
  • Choice of power supplies
  • DIGSI 4 setting software – powerful custom logic etc
  • Up to 8 binary inputs
  • DNP serial or IP protocol and IEC 61850 supported
  • Intertrip and remote trip
  • Overcurrent guard and backup overcurrent
  • Communication of binary information between relays

For more advanced functionality. such as transformer in-zone or multi-terminal schemes, the ‘SIPROTEC 5’ 7SD82/6/7 series is recommended. These are all very cost-effective protection devices.


      Fault Passage Indicators SMART NAVIGATOR 2.0, SMART NAVIGATOR 2.0 SWER & Pole Master    

A new variant of the Horstmann ‘SMART NAVIGATOR 2.0’ FPI has been released, the ‘SMART NAVIGATOR 2.0 SWER’. We’ve summarised these product offerings for you.

SMART NAVIGATOR 2.0,        Pole Master,       SMART NAVIGATOR 2.0 SWER.


  • Master unit with inbuilt GSM modem – just add a SIM card to enable DNP connectivity
  • Master unit communicates to two Satellite units mounted on the other phases
  • Self-powered (+ 72-hour backup rechargeable battery) [requires a 5 A current (averaged over 24 hours) to maintain line-powered functions (with once per day communications). With greater than 40 A current, data reporting at 15-minute intervals becomes possible].
  • Load current and conductor temperature monitoring
  • Directions power flow and directional fault indication

Low power option (with above SMART NAVIGATOR 2.0):
SMART NAVIGATOR 2.0 uses line power to recharge batteries that drive the device’s electronics.
However where the line current is below the 5 A average current needed to enable direct GSM communication from the Master FPI, then it is possible to install three Satellite units. (The three Satellite units require an average of 1.5 A current to maintain their communication capability) These three Satellite units can communicate to the ‘Pole Master’, pole mounted communication device.

The ‘Pole Master’ has an inbuilt GSM modem that just needs a SIM card added to enable DNP connectivity. The Pole Master is supplied with small solar cell to charge its battery – so no auxiliary supply is needed at the pole, making installation very easy. If GSM communication is not desired (or signal is not sufficient due to remote or difficult site location), the Pole Master will soon be available with an RS-232 DNP interface option to allow connection to a customer-provided radio etc.

Unlike the SMART NAVIGATOR 2.0 that uses line power to recharge batteries, the SWER unit is powered by long-life lithium batteries. The SWER unit will operate for approximately 15 years (including up to 400 hours of flashing!) on one set of field-replaceable batteries.

If remote communication is desired, a Pole Master can be fitted on the pole. (See above for Pole Master description).
The SWER unit is like a ‘Satellite’ SMART NAVIGATOR 2.0 in terms of its communications, however being battery operated, it requires no minimum current to maintain operation.

Designed for Single Wire Earth Return (SWER) systems, the SWER can also be used on non-SWER systems. As the Pole Master can communicate to up to three nearby SWER devices, this allows the SWER to be used on very low current three phase circuits.

The SWER FPIs do not feature conductor temperature monitoring, and have once-per-day communications to SCADA (other than if a fault occurs, where the units will instigate immediate communications). The SWER does not feature fault direction, but do have an interesting customer-requested feature – a reverse power alarm that can be used to detect imbedded generation etc.

The SWER device can indicate fault currents as small as 6 A (with 100 ms duration), with a setting range of 6-100 A pick-up possible.

Contact us for more information.

Copyright 2018 HV Power Measurements and Protection Ltd