The inverter maker conducted tests and found the Tigo Energy TS4-R-F-42 could not always supply the rapid shutdown function called for by a new U.S. safety standard when applied in commercial and industrial systems featuring its inverter tech.
SMA is contacting U.S. commercial and industrial customers after discovering problems with Tigo Energy’s TS4-R-F 42 Sunspec Rapid Shutdown device.
Some 28 U.S. states have introduced new NEC2017 690.12 module-level shutdownrequirements. Under the new standard, all conductors within 30cm of an array must lose voltage to 80V or less within 30 seconds of rapid shutdown initiation. One method of complying with the new safety standard is to install module-level power electronics such as rapid shutdown devices.
However, having carried out tests in its lab German inverter maker SMA discovered deviations in some instances from the Sunspec Rapid Shutdown standard when the Tigo product is combined with SMA inverters in commercial and industrial applications.
“The recall only affects a few customers, exclusively in the commercial sector in the USA,” an SMA spokesperson told pv magazine. “We have informed these customers personally and in writing.”
The inverter manufacturer says it is already exchanging affected products with the new TS4-R-F to comply with the standard.
SMA began shipping the TS4-R-F to residential and commercial customers in the U.S. in September. For the U.S. market, SMA sold its Sunny Tripower Core1 string inverter with the TS4-R-F shutdown device for NEC2017 standard compliance.