Capacitor Type Power Packs for Tripping 12 kv Circuit Breaker

Do you use 24 V DC trip coils? Not 110 or 220 V DC? What type of breaker is it? Do you monitor the coil(s)?

If it's really 24 V DC there are a couple of supercap buffer units but be aware that the voltage may be slightly lower than 24 V and I'm not sure if those units can be paralleled (I'd have to check the specs, I don't know them well, I use battery systems (and where required DC/DC converters or inverters). A typical config is one or more large main 220 V (or 110 V) batteries but that's for larger systems.Those supercap buffer units are also relatively new (a few years, not decades).

The official name of the product that you should search for is a "capacitor trip device", they are sold by most companies that also provide protection relays and/or instrument transformers. For example, Instrument Transformer Inc sells them, but they are now part of GE and if you are a GE competitor, you may want to look elsewhere.

Example: http://www.gedigitalenergy.com/app/DownloadFile.aspx?prod=tr-pcc&type=4&file=18

Thank you for the information.

Interesting to know. Didn't know as I'm mostly involved in automation and control rather than in MV and especially HV substation design details.

Me too, but at one point I was working on a control system for a rotating UPS at a hydro dam used in maintaining control of the switchgear. I came across the term "capacitor trip device" and I initially assumed it was for protecting capacitors, which made no sense for what I was working on. So when I looked into it, I got an education on something I had never encountered before.

That little tidbit has been rattling around uselessly in in my brain for probably 20 years, waiting for that question to be asked... This is the first time I have thought about it since then.

I rated your reply above for good answer.

Interesting device, especially the output DC voltage of 169 V DC or 338 V DC. I don't know the trip coil voltages for MV and HV gear in the U.S., here in continental Europe you mostly find 110 V DC and 220 V DC, sometimes even lower. But as there's no DC/DC to stabilize the output voltage there will be a voltage drop during the capacitor discharge so maybe the 169 V are intended for 110 V DC trip coils.

Capacitor buffer units are also used for very short-term buffering of undervoltage release circuits of breakers and more recently DC UPS with supercaps have appeared too though those I've seen have a slightly reduced output voltage (e.g. not reaching 24 V for one rated for 24 V buffering).

Rotating UP... There could be intersting topics about, there are large datacenters relying on rotaty UPS systems (either high speed gyro-based or no-break synchronous electric motor/diesel engine/generator units).

In the substations and powerplants I know here in continental Europe they mostly use 110 or 200 V DC battery systems, controls are still often 48 V DC (either battery back-up or DC/DC from 110/220 V DC), typically mixed with 24 V. Some try to focus on 24 V DC wherever possible because many automation and instrumentation COTS are mostly available for 24 V DC (or 230 V AC but that's less interesting because UPS and inverters are considered as less reliable than battery-based DC).

Here are links for a couple of other cap trip devices. We have used the TimeMark unit before, and it works. I can't speak specifically for the Schneider unit.

http://www.time-mark.com/Special-Controls-Model-295.aspx

http://www.schneider-electric.com/products/ww/en/4700-protection-relays-by-range/4705-micom-accessories/60732-micom-e124/