ayerforce
Member
- Location
- Hubertus, Wisconsin
- Occupation
- Electrical contractor
I wired a new (probably German) machine for a customer today. Their building is served with an 800 ampere 480Y/277 service. The manufacturer supplied (thankfully)a 55kva 480 X 400Y/230 transformer to provide the proper input voltage to the machine. I first wired the primary (480 delta) of the transformer and bonded and grounded X0 on the secondary. I then energized the transformer and tested the secondary voltage. 410 volts. Good to go. I finished connecting the secondary conductors to the machine and left, since the machine setup people are the only ones allowed to apply power to the actual machine.
I recieved a call tonight from the customer. When the machine setup person "turned on" the machine, 75% of the UPS devices on the engineering office computers malfunctioned and now only output approximately 83 volts. Input power at the receptacles is 120 volts. On the other end of the shop, coincidently, the new machine is functioning perfectly.
That's all the information I was given. I don't know if this happened when they energized the transformer, or when they actually started testing this machines functions. Either way, I've got to check this situation out tomorrow and I doubt that I'll find anything wrong other than 6 defunct UPS units. The UPS units are plugged into 120 volt receptacles that are fed from a 208Y/120 panelboard fed from a 480 X 208Y/120 transformer which is fed from the same service as the new machine.
Have any of you experienced a similar situation? An pointers?
I recieved a call tonight from the customer. When the machine setup person "turned on" the machine, 75% of the UPS devices on the engineering office computers malfunctioned and now only output approximately 83 volts. Input power at the receptacles is 120 volts. On the other end of the shop, coincidently, the new machine is functioning perfectly.
That's all the information I was given. I don't know if this happened when they energized the transformer, or when they actually started testing this machines functions. Either way, I've got to check this situation out tomorrow and I doubt that I'll find anything wrong other than 6 defunct UPS units. The UPS units are plugged into 120 volt receptacles that are fed from a 208Y/120 panelboard fed from a 480 X 208Y/120 transformer which is fed from the same service as the new machine.
Have any of you experienced a similar situation? An pointers?
