ECN Forum Forums General Topics of the Trade General Discussion Area Contactors, 208v, 240v lighting questions.

If they're powering something using the high leg that could be the problem. Single-phase loads can't be fed by the high leg and the neutral.

That voltage will read 208V on a meter but that's just a mathematical coincidence; you can't put any load on that or you're going to have nothing but trouble. All you have available to you with that type of system is 240V-3phase and 2 places that you can get 120V-1phase from.

Also, the total of the single phase loads is limited to 5% of the transformer rating or you'll start getting overheating problems in the transformer ahead of the Service.