Where can I find a 75 KVA 208/120 Delta Y Transformer Secondary Time Current Curve?
- Thread starter Snowjob
- Start date
- Status
- Location
- Massachusetts
I do not think there is a time current curve for a transformer.
Your transformer is rated 208 amps on the secondary.
Your transformer is rated 208 amps on the secondary.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Time current curves are generally for overcurrent devices. What information about transformers are you looking for?
ptonsparky
Tom
- Occupation
- EC - retired
Are you looking for the inrush current value?
ptonsparky
Tom
- Occupation
- EC - retired
Put in a bigger breaker. That always works...for a while
See Table 450.3(A)
See Table 450.3(A)
Last edited:
- Location
- Illinois
- Occupation
- retired electrician
There should be a damage curve for the transformer.
Typically motors and transformers have what are called Thermal Damage Curves. The curves determine the time a certain amount of current can be withstood in the windings, stator, rotor, etc before thermal damage occurs to the device.
I would contact the manufacturer for such a curve. Sometimes software programs such as Easy Power & SKM will have a default curve that you can use.
I would contact the manufacturer for such a curve. Sometimes software programs such as Easy Power & SKM will have a default curve that you can use.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Normally 75kVA is too small to worry about, so I just use the standard curves that come with my software library (I use PTW from SKM). And, I don't think I have ever seen fuses or breakers properly sized, using NEC450.3, that provide the coordination I would demand on a much larger (i.e. MVA) transformers protected by relays.
- Status