How the customer can test the Tesys GV2, GV3, GV7 MPCB thermal - magnetic tripping curve?

In general the thermal overload relay testing should be done as defined in IEC60947-2 standard.

Concerning thermal overload tripping level level of GV2, GV3, GV7, you will have to refer the tripping curve provided in our catalogue (attached). The Tesys GV2, GV3, GV7 MPCB usees the bimetal sensor and follow the IDMT curve for the thermal overload condition.

For your information the IEC60947-2 standard define 2 different point for thermal overload and our GV* respect this 2 different standard point.
- The first point is when current is equal to 1.2 time Ir ( Ir =current setting ) the GV* should trip within 2 hours( curve on catalogue attached)
- When current is equal to 7.2 times Ir the GV7 must trip within class product. GV* are class 10 product so the tripping time ate 7.2 times Ir is bellow 10 seconds ( you will see it on the curve in catalogue page.

For example, as you will see the curve cover the whole GV7 range regardless the GV7 type RE or RS and regardless the size from GV7*20 to GV7*220.As the curve is for all products the times provided here are only indicative and if your customer do some test at different level of current injection than the standard definition point they may see some difference between curve and time they record.

Also for good reliability of our product each product is individually tested and setting range is unique for each product.

In Conclusion
- Thermal curve provide indicative time, and product will trip within 2 hours at 1.2 times Ir and in less than 10 seconds at 7.2 times Ir.
- Curve gives tripping time indication only.
- The magnetic tripping time is level +/- 20%
- The product is electromechanical device and follow the IDMT curve , should not be compared to electronic device.

If you require the definite type tripping for your motor application, you have to use definite curve protection relay which can trip the relay with in a definite time when current exceed the normal current.

Hope this information are clear for you and you will be able to answer to your customer.

Released for:Schneider Electric South Africa