Recent content by Coco_HueHueHue

Hi Waross, Its only distributed generation one of our client wants to build to sell power to the main utility. I guess they evaluated to power of the river sufficient to mechanically move this turbine/generator. FYI, my question was general, so I mentioned 333kW generator. But, in reality, it...

Thanks for so many details. Most of your answer is aligned with what I was searching for as information. FYI, they are not PMG used to energize the AVR of a bigger unit. It is really a project using very small hydro generators/turbines. The main generator is 333kW (will probably end up as you...

Hello, Currently working on a project where we integrate a Permanent Magnet Synchronous Generator (PSMG) into a Distributed Generation plant. I did that in the past for Asynchronous Generator and Synchronous Generator (field excitable), but never for PSMG. The unit is only 333kW. The general...

Hello, I believe IEEE 519 is the way to go. However, nothing prevents you from correcting the harmonics content "nearer" to your source of harmonics. Take the example of a MV PCC (25kV) with a MV substation transformer 25/4.16kV and a LV substation transformer 4.16/0.6kV. If your source of...

Thank you jraef, that is exactly the kind of product I was searching for to add on the contact when you see old breakers that seem to have a tulip system that looks like it has no more lubricant on it.

You can definitely implement genset protections into a PLC (temperature, oil level, etc.) to initiate a trip of the main breaker. The PLC could send an input to an electrical protection relay managing the main breaker. But electrical protections need to be implemented using approved protection...

Thanks for the input. I was more looking towards the breaker electrical racking connections to the equipment bus bars though. If you have any idea for that one, it would be appreciated.

Hello, I cannot identify a grease that would be good for breaker connections to switchgear busbars in 600V and 15kV equipment. Am I asking myself too many questions and a simple good quality dielectric grease from an auto part do the job or if there are specific product for that. I know for...

For everyone's interest (who are interested on the subject). SEL wrote to me to keep any ferroresonance protection if there was any as the relay does not prevent it in any way.

Sure, here it is.

This comes from a Schneider Cahier Technique. The exemple in figure 11 is exactly how its done in the panel I am working on. The cahier technique even has explanations on how this setup prevents or damps the phenomenon of ferroresonance. However, I understand the setup at figure 12 is said...

Hi Waross, Sorry if my question isn't clear. My question is mainly: Should I keep the resistor previously installed in parallel of the PTs secondary when replacing the old electromechanical relays by the new SEL-751 relay. Can the SEL-751 relay prevent the ferroresonance phenomenon? Thanks! Coco

Yeah, thanks for you input. I will see if other people have different view of this. But, in SEL-751 instruction manual, I found zero mention of the word "resistor" in regards to PT connection and the word "ferroresonance" isn't mentioned once. I am starting to be convinced that those resistors...

Hello, I am working on modifications onto an old protection panel. There are 80 ohms resistors in parallel (Y-G) of the Y-G / Y-G PTs secondary on each phase (primary is 3ph/3wire 25kV and directly connected to the utility). This is mentioned as ferroresonnance protection and it makes sense...

Personnaly, i always exclude the main unless the equipment is arc-rated as it was mentioned above. To me, added insulating barriers is not enough. If the fault occurs upstream of your main device, but inside your equipment, what tells you that you will not receive the blast in the face? Even if...