LENOX — The lights went out, traffic signals went dark, wi-fi shut off and computers powered down not once, not twice, but three times in much of Lenox on Saturday, bewildering residents and business owners since there was no obvious cause such as stormy weather.

There were no trees or utility lines down, police reported.

The power was out for about 1,900 customers of National Grid between 2 and 4 p.m., from 9:30 to 10:30 p.m. and briefly just before 11:30 p.m.

The tripleheader blackout was caused by a malfunctioning circuit-breaker control board at a Lenox substation, said National Grid spokeswoman Darlene Masse. It took technicians three tries to repair the system, but customers using the company's app on their smartphones or tablets were kept informed of the expected power-restoration schedule.

Only a moderate impact was reported, primarily along the Route 7 and 20 bypass, where motorists crossing the highway had to navigate without signals.

Residents cited inconvenience caused by the need to reset electronic clocks and reboot computers three times. Normal service was back on Sunday.

The affected area involved most Lenox customers of National Grid, except along the commercial district north of Holmes Road. The village of Lenox Dale is served by a different utility, Eversource (formerly Western Massachusetts Electric Co.)

National Grid extended apologies to its customers for the inconvenience, Masse said.