iec 947-1 compliant overload unit

[ctolbert]

I have an interesting Italian overload unit that a customer is using....no brand name.

It has a little chart on the front that has the words FLC (which I assume is full load current) and Y/Delta. The vertical scale shows the current relationship to voltage on either side. I.E. Y or 460 on one side and Delta or 230 on the other side.

The issue is the dial for the overload gap is the identical scale as the Y or 460 volt FLC side.

Does the vertical scale represent the overall KVA rating of the overload?

I understood (and maybe I'm wrong) that thermal overloads were a function of material and resistivity and does not disiminate voltage sources. I.E. The unit trips at 65 amps regardless if it is 230 vac or 460 vac.

Is anyone familiar with this type of overload?

Carl

 

[buzzp]

I have designed some overloads for the European market. There shouldn't be any difference between 230 and 460 volt systems as far as setting the overload trip point. I would feel 99.999% sure that the dial to adjust the trip current would not change based on using 230 or 460 volt system. Thanks Buzzp