K
Knobhead
This is one for any guys that have worked on HV stuff
Asked by a mate to check a switching schedule for an 11KV system. 3off 20MVA 33/11KV ATC transformers feeding a large site. He needed to parallel two 1MVA 11/.44KV transformers for a short while.
So I read through his schedule and noticed he’d missed out balancing the ATC’s voltage (you put them in to leader and follower mode not independent as is normal). Phoned him up and pointed it out. “Yes OK will have a look at that” he didn’t!
He closed the bus section ACB and two 1MVA transformers are now trying to sort out a fight between two unbalanced 20MVA transformers. I don’t know who set up the O/L protection but it must have been perfect. TX1 went out on HV O/L, TX2 went out on LV O/L at the same time!
Data centre, pub, a large potion of the works plus half the village all blacked out!
Asked by a mate to check a switching schedule for an 11KV system. 3off 20MVA 33/11KV ATC transformers feeding a large site. He needed to parallel two 1MVA 11/.44KV transformers for a short while.
So I read through his schedule and noticed he’d missed out balancing the ATC’s voltage (you put them in to leader and follower mode not independent as is normal). Phoned him up and pointed it out. “Yes OK will have a look at that” he didn’t!
He closed the bus section ACB and two 1MVA transformers are now trying to sort out a fight between two unbalanced 20MVA transformers. I don’t know who set up the O/L protection but it must have been perfect. TX1 went out on HV O/L, TX2 went out on LV O/L at the same time!
Data centre, pub, a large potion of the works plus half the village all blacked out!