Earthing electrode testing (PRAM): why, how often and how much it costs

Earthing electrode testing, known in practice as PRAM measurements, is the operation by which it is determined whether a building’s earthing installation still correctly protects people and equipment. In short: the earthing electrode is measured periodically, the result must be below the permitted value (typically 4 ohms for an ordinary installation), and the result is documented through a PRAM test report issued by an authorised laboratory. At bransam.ro we carry out both the measurements and the installation or refurbishment of the earthing electrode, with prices from 250 lei for testing and from 900 lei for a new electrode.

What PRAM means and why it matters

The acronym PRAM comes from “Protection through Relays, Automation and Measurements” (Protectie prin Relee, Automatizari si Masuratori), and in the everyday language of electricians it refers to the electrical checks carried out by an authorised laboratory. The most common PRAM check for residential customers and small businesses is the measurement of the dispersion resistance of the earthing electrode.

The earthing electrode is the component that “discharges” fault currents into the ground. If a cable becomes damaged and energises the casing of an appliance or a metal surface, the earthing electrode together with the protective device (the circuit breaker or the residual current device) must disconnect the circuit quickly, before a person touching the equipment is electrocuted.

Over time, the dispersion resistance increases: the electrodes corrode, the soil dries out, the connections loosen. An electrode that measured 2 ohms when installed may, after years, reach 15-20 ohms, becoming practically ineffective. The only way to know the condition of the electrode is to measure it.

When PRAM testing is mandatory

• at the acceptance of a new installation or of a recently completed electrical connection (bransament);
• at the commissioning of equipment that requires earthing (boilers, pumps, machinery, distribution boards);
• periodically, during operation, to confirm that the values remain within limits;
• after modifications, repairs or extensions of the electrical installation;
• at the request of certain bodies (ISU, insurers, energy audits, occupational safety inspections).

What values the earthing electrode must have

The target value depends on the role of the electrode and the type of installation. Below are the indicative values most commonly encountered in practice for civil buildings and small industrial premises. For special cases (lightning protection, complex industrial installations), the exact value is established through a design project and in accordance with the regulations in force.

Important to remember: an electrode “passes” the test only if the measured value is below the permitted threshold. A higher value means the electrode needs to be improved, by adding electrodes, treating the soil or refurbishing the connections.

How the measurement is carried out

The measurement is performed with a specialised instrument (an earth resistance tester / tellurometer), using the three-electrode method or equivalent methods, under conditions that reflect the real state of the soil. The technician measures the dispersion resistance, checks the continuity of the connections to the protective neutral and the condition of the visible connections, then records everything. The complete procedure and the equipment used are described on the dedicated page PRAM measurements.

The PRAM test report

The result of the measurement is not simply a value communicated verbally, but an official document: the PRAM test report. It is recognised by the distribution operator, by the ISU, by insurers and by labour inspectorates.

A PRAM test report typically contains:

• the beneficiary’s details and the address of the site;
• the measured value of the dispersion resistance and the permitted value;
• the measurement method and the instrument used (with its serial number and metrological verification);
• the conditions under which the measurement was carried out (soil condition, temperature);
• the conclusion: electrode compliant or non-compliant;
• the date of issue and the validity period, the signature and the stamp of the authorised laboratory.

The report has a limited validity period, which is why the test must be repeated periodically. Keep the document: it will be requested during inspections, at grid connection (racordare) or when renewing certain approvals.

How often the earthing electrode is tested

The frequency depends on the type of site and the applicable requirements. The values below are indicative, frequently encountered in practice; the exact frequency is established in accordance with the regulations in force and the decision of the owner/administrator.

In addition to the periodic deadlines, measure the electrode whenever signs of a problem appear: mild electric shocks when touching appliances, repeated tripping of the residual current device, excavation work near the electrodes or after severe weather events (lightning strikes).

How much testing and installing an earthing electrode costs

The costs are indicative and are confirmed according to the type of site, the access to the electrode and the nature of the soil. The final price is established after assessment.

For a complete picture of the costs of electrical works, consult the prices page or use the connection cost calculator tool. If you need a new electrode, see the dedicated earthing electrode service.

Why choose SUN WATT (bransam.ro)

SUN WATT SRL is an ANRE-certified company for execution and design, with experience in electrical connections (bransamente) in Bucharest, Ilfov and Giurgiu and DIU (Utilisation Installation Dossier) nationwide. We carry out PRAM measurements, issue the test report and, if the electrode is non-compliant, we install or refurbish the earthing installation so that it reaches the permitted values.

Do you need a PRAM check or a new earthing electrode? Call 0733 097 440 or write to us via the contact page for a quote.