CHECKS & MEASURES

The continuous development of technology and regulations of sector require constant quality monitoringof electrical quantities and plant efficiency. Through the use of correct techniques and tools we are in able to supply the following types of measurements on request:

• Electrical continuity tests
• Insulation resistance measurement up to 1000V
• Differential test
• Measurement of earth resistance and soil resistivity
• Energy measures
• Verification service with relay test box, as required by the CEI 0-16 and CEI 0-21 standards on general protection (SPG) and interface (SPI) systems of active and passive systems connected to low and medium voltage networks.

In particular we summarize in a schematic way the requirements required by the CEI 0-16 and CEI 0-21 standards regarding the verification of the interface protection system (SPI) of the production plants (active plants) connected to the low and medium voltage network and the general protection system (SPG) which covers both active and passive users connected to the medium voltage network.

FIVE-YEAR CHECKS
General Protection System (SPG)The V2 variant to the CEI 0-16 standard introduced, for the first time, the obligation to check every five years the general protection system (SPG) of the plants connected to the medium voltage network, active and passive, using a relay test box (see CEI 0-16 V2-Art.8) and send the results of the test to the Network Operator in electronic mode as indicated by the manager. The standards apply to new plants, so that this obligation concerns for the time being only the plants that came into operation starting from 1 August 2016, date of entry into force of the V2 variant to the CEI 0-16 standard.For systems connected to the low voltage network, the general protection system consists of a general automatic circuit breaker and therefore no periodic checks must be carried out using a test cassette, but only the usual control activities.

Interface protection system (SPI)
According to the new edition of the CEI 0-21 (2016) standard and the V2 variant to the CEI 0-16 standard, the interface protection system for the systems of active users connected to the low and medium voltage network must be tested every five years via relay test box (see CEI 0-16 V2-Art.8). The new standard CEI 0-21 (2016) and the variant V2 to the standard CEI 0-16 do not define power limits for the execution of the tests, but resolution 786/16 established that the aforementioned tests using the relay test box must be performed on all production plants with power exceeding 11.08 kW, while also extending this obligation to the plants that went into operation before 1 August 2016.

ANNUAL CHECKS
Medium voltage connected systemsFor the plants connected to the medium voltage network, the V2 variant to the CEI 0-16 standard requires, in addition to the five-year checks above, also the annual visual check of the SPG regulations for all the plants connected to the medium voltage network, active and passive, and of the SPI of the active users, (see CEI 0/16 art.8.5.12.1, art. 8.8.8), reporting the result on a special maintenance sheet.Resolution 786/16 does not concern the annual checks of the GSP and the SPI, ie the CEI 0-16 standard does not have retroactive value as regards the annual verifications, which certainly apply to the plants that started operating from 1 August 2016 (date of entry into force of the V2 variant to the CEI 0-16 standard). For plants that came into operation before 1 August 2016, the obligation may derive from the operating regulation signed by the user, if it provides for such annual checks. Low voltage connected systems. For systems connected to the low voltage network, the CEI 0-21 standard does not require any annual verification (see CEI 0-21 annex A), without prejudice to the obligation for the user to carry out regular maintenance and guarantee the correct operation of SPI and SPG (see CEI 0-21 G5).