Over 800 homes in Merthyr Tydfil are without power this morning.
Western Power Distribution said that 889 properties are affected by a power outage.
They added that the problem should be resolved by 11am.
The postcodes affected are: CF47 8PQ, CF47 8HJ, CF47 8SA, CF47 8SR, CF47 8SP,CF47 8YR, CF47 8NR, CF47 8NU, CF47 8TH, CF47 8LQ CF47 8TN, CF47 8SW, CF47 8SF, CF47 8TG, CF47 8PD,CF47 8PX, CF47 8YS, CF47 8SD, CF47 8NN, CF47 8RS,CF47 8EY, CF47 8TP, CF47 8PP, CF47 8SL, CF47 8NS,CF47 8SB, CF47 8PJ, CF47 8SN, CF47 8TW, CF47 8NW,CF47 8RR, CF47 8SY, CF47 8SU, CF47 8TA, CF47 8NP,CF47 8TE, CF47 8SG, CF47 8SS, CF47 8SH, CF47 8TD,CF47 8NT, CF47 8HX, CF47 8ST, CF47 8RE, CF47 8TF,CF47 8RP, CF44 0DT, CF47 8NL, CF47 8EJ, CF47 8TB,CF47 8SE, CF47 8TL, CF44 0BY, CF47 8EX, CF47 8AX,CF47 8TT, CF47 0AJ, CF47 8TS, CF47 8RW, CF47 8QD,CF47 0AY, CF47 8YT, CF47 8RN, CF47 8YU, CF47 8TR,CF47 8RA.
The outage was reported at 9.15am this morning.
Western Power Distribution said that it was a high voltage incident.
They said: "These incidents tend to be larger, affecting the wider area and could mean your neighbours are off supply too."
