The medium voltage switchboard is no longer just copper, fuses and relays: it is a network node. IEC 61850 is the series of standards that defines how the devices in a substation or a switchgear lineup describe their data and talk to each other over Ethernet, in a common engineering language. And the regulatory direction already points at that network: Resolution 40333 of the Ministry of Mines and Energy, issued on 23 July 2026, ordered the regulation of cybersecurity in the power sector. It is aimed at network operators and the National Dispatch Center (CND), and it does not bind a plant directly; it is a signal of direction.

What is IEC 61850, and what do MMS, GOOSE, SV and SCL mean?

It is the series "Communication networks and systems for power utility automation" from technical committee 57 of the IEC (International Electrotechnical Commission). The IEC itself stresses that it is much more than a protocol: it includes a data model, a configuration language, real-time mappings and cybersecurity (the IEC 62351 series). Its current introduction is the technical report IEC TR 61850-1-1, from February 2026.

Four acronyms are enough to read it. MMS (Manufacturing Message Specification) is the client-server messaging for supervision and control from SCADA. GOOSE (Generic Object Oriented Substation Event) is fast event messaging between relays, such as interlocks and trips. SV (Sampled Values) is the continuous stream of current and voltage samples: the process bus. SCL (Substation Configuration Language) is the set of engineering files (ICD, CID and SCD) that describe and configure the system. MMS and GOOSE are mapped in part 8-1, SV in part 9-2 and SCL in part 6.

What physically changes in a medium voltage switchboard or switchgear panel?

Measurement, signalling between devices and the way you test all change. The power circuit and the busbars stay the same.

The conventional current and voltage transformer, with its ferromagnetic core, is replaced by low-energy sensors: a Rogowski coil for current and a resistive or capacitive divider for voltage (low-power instrument transformers, or LPIT). According to ABB, they do not saturate. The relay must accept those inputs and can act as a merging unit, the device that publishes the sampled values on the network.

In an MV switchgear panel the relays sit a few meters from the instrument transformers, so the copper saved inside the panel is smaller than in a high voltage substation. The value lies in flexibility, reusable engineering and the ability to add switchgear panels to the same network.

What do you gain, and with what numbers?

The public figures come from manufacturers and typical cases: treat them as an order of magnitude, not as a promise. According to ABB (CIRED 2025), a single set of sensors serving both feeder protection and busbar differential protection allows up to 20 percent savings in switchgear footprint. In a typical 10-panel case, ABB calculates primary circuit losses of 14.1 MWh per year with sensors versus 22.7 MWh with conventional transformers.

According to Siemens, instrument transformers with LPIT weigh 90 percent less, and direct breaker tripping from the merging unit can take under 1 ms, although the manufacturer itself notes that this depends on the site. And for people, Siemens highlights that no CT secondary circuits remain that could be opened under load.

What risks does it bring, and where does cybersecurity come in?

A networked switchboard is a cyber surface that did not exist before. GOOSE and SV travel on Ethernet layer 2 and, by default, without encryption. IEC 62351-6 defines authentication for both, but cryptographic latency has held back its use in real time; in practice, message authentication codes and network segmentation are used.

Two families of standards complement each other: IEC 62351 protects the protocols and IEC 62443 protects the system and the device, with zones, conduits, hardening and secure development. On top of the network risks come engineering ones: SCL configuration across vendors remains demanding, mixing editions (1, 2 and 2.1) is a risk, and staff must move from the multimeter and the terminal block to network analyzers and SCL files.

In Colombia, article 7 of Resolution 40333 of 2026 gives the CREG 24 months to regulate cybersecurity, with periodic audits and a sector CSIRT, aligned with international standards, including those of NERC and the IEC. The text does not name IEC 61850 or IEC 62443 and is aimed at the agents of the transmission and distribution system (see the Ministry's press release, in Spanish).

When is digital switchgear not the right choice?

It is not the right choice for a small switchboard with few feeders, no SCADA, no growth plan and no staff to maintain an IEC 61850 network. Nor when replacing a panel in an existing substation without SCL engineering: a relay with an IEC 61850 port (MMS and GOOSE) may be enough, without a process bus.

Avoid it if the schedule is tight and the engineering is not closed, because commissioning requires testing messages, or if there is no OT cybersecurity policy.

What should you ask when specifying switchgear with IEC 61850?

Specification lesson. When specifying an MV switchboard or switchgear panel, require IEC 61850 relays with a valid conformance certificate, the SCL file delivered with the FAT and a zone-based cybersecurity plan under IEC 62443. A process bus with sensors is an architecture decision, not a default requirement.

A case in Colombia: the Portugal substation of Enel Codensa

In January 2021, La República reported the start-up of the Portugal substation of Enel Codensa, in Engativá (Bogotá), as the country's first 100 percent digital electrical substation: 40 MVA, information over fibre optic, IEC 61850 compliance and an investment above COP 25,000 million.

Industrias Ectricol S.A.S. supplied three shelters (115/34.5/11.4 kV) with the control, protection, communication and auxiliary services switchboards. This article does not describe the communications architecture or each supplier's scope over the protection equipment. See the project page.

Frequently asked questions

What is IEC 61850 in one sentence?

A series of standards that defines how the devices in a substation or switchgear lineup model their data and communicate over Ethernet (MMS, GOOSE and SV), with a common engineering language, SCL.

What is the difference between GOOSE, MMS and SV?

MMS serves supervision and control (SCADA) in client-server mode. GOOSE sends fast event messages between relays, such as interlocks and trips. SV carries the continuous stream of current and voltage samples of the process bus.

Does digital switchgear replace copper entirely?

No. The power circuit and the power wiring remain, and a hardwired backup is usually kept for critical functions. What shrinks is the signal wiring between devices.

Is digital switchgear safer or less safe?

It improves personnel safety, because no CT secondary circuits remain that could be opened under load, according to Siemens. In exchange it introduces a cyber surface that is managed with IEC 62443 and IEC 62351.

Does my plant need IEC 61850 today?

It depends. If you have several MV feeders, SCADA and a growth plan, it makes sense to require IEC 61850 relays now. A process bus with sensors is evaluated case by case.