Q. What is the method to find out the exact pickup current settings of a "time overcurrent relay" and the tripping curve used/selected in an old electronic relay.
Sounds like the first thing you want to find is a qualified relay technician, or equivalent person. The relay tech would be equipped with a test set that directly interrogates the relay function. A common test procedure would be to test and calibrate the Long Time (LT) pickup and two points on the delay curve (Lever or Timer Dial). Then test & calibrate the Instantaneous Action (IA). The relay tech should have the curve from the original instructions booklet, which is usually noted on the manufacturer's name plate on the relay.
We have an assignment to replace some very old model electronic Time overcurrent relays with the new model digital relays. The settings for the old relays are not available. We want to find out the existing settings so we can configure the new relays accordingly. Because if the new relays are not configured properly these may effect the up stream or down stream protection system.
We have the latest secondary injection test set alongwith a qualified technician but we are confused to get the exact existing settings. Thats why I put this question here that may be some one faced the similar problem and might help us.
Q1. How we can find out its exact pickup current (not tripping current)?
Q2. Curve used alongwith its multiplier settings. I mean how we can compare its tripping current and time with the standard Curves (IEC, ANSI or IAC) etc. so we can assume that this specific curve and multiplier was used when this relay was configured.
If we have this data available then it is easy for us to configure the new digital relay which will replace this existing old model relay.
We have an assignment to replace some very old model electronic Time overcurrent relays with the new model digital relays. The settings for the old relays are not available. We want to find out the existing settings so we can configure the new relays accordingly. Because if the new relays are not configured properly these may effect the up stream or down stream protection system.
We have the latest secondary injection test set alongwith a qualified technician but we are confused to get the exact existing settings. Thats why I put this question here that may be some one faced the similar problem and might help us.
Q1. How we can find out its exact pickup current (not tripping current)?
Q2. Curve used alongwith its multiplier settings. I mean how we can compare its tripping current and time with the standard Curves (IEC, ANSI or IAC) etc. so we can assume that this specific curve and multiplier was used when this relay was configured.
If we have this data available then it is easy for us to configure the new digital relay which will replace this existing old model relay.
Time Over Current Protection Relay
Re: Time Over Current Protection Relay
