Surge Protection for Nord Keyboards

[Hlaalu]

I hope my first answer was clear enough to the OP.

I did edit my second message though, as it possibly was the source of misunderstanding.

[CountFosco]

OK. So, in terms of the life cycle cost of the power supply, you'd like to find an optimisation between the low cycle fatigue caused by plugging it in (does that even exist?) and the high cycle benefit (does that also even exist?) of having the device plugged in (and presumably switched on). The end result of which would be some kind of schedule of unplugging and replugging (and switching) the keyboard, independent of whether it's in use or not. I completely agree with you, it's weird how you couldn't find a lot of results on the internet for that.

[Hlaalu]

Well thank you so much for being around in this forum saving me the time to search elsewhere in the internet!

[JohnT]

In the studio, EVERYTHING is powered through a 1500VA UPS. Speakers go through the "surge only" side.
For live gigs, EVERYTHING is powered through a Furman digital surge protector.
I have not had ANY power related issues to any of my equipment for 12 years now.
I live in Florida, the lightning capitol of the US.

Just my two cents.

[DavidSydney]

I don't have a definitive answer, but I do know this tradeoff between stress to power supplies from "startup spikes" and continuous use has been around for a long time.

In 40+ years of using computer, audio and stage electronics, I've had just a few power supplies fail. Almost all computer switchmode supplies. Some failed when I plugged in an IEC connector (before I switched on the device). Some were on servers that had been runnning 24/7 for c. five years before they conked one day

I've never had a good quality linear (conventional transformer/rectifier/filter/regulator) power supply fail. Note that the Nords use this type of supply (at least my Electro 6 and original Stage do!).

So I don't think this is really a concern with good quality equipment. Switch it on and off at will. Use appropriate protections for your location and situation. JohnT's approach is pretty much optimum.

Another two cents!

[23skidoo]

Remember that AC flips between max positive and max negative 50 or 60 times per second, always. The main point of failure in most any power supply (that is properly specified for the job, that is) are the filter capacitors, which handle the majority of the ripple transient after the rectifier. High quality supplies tend to keep these in the low-voltage (post-transformer, post-rectifier) side - there are occasionally filter capacitors pre-rectifier but those are usually just noise suppression caps and of small value. All of these capacitors are capable of handling high dv/dt ("spikes") within their voltage tolerances and due to the transformer impedance itself, the inrush spike is already limited significantly. As a result, there is insignificant lifecycle diminuation from power cycles related to plugin/out or switch on/off of a well designed power supply - they will live out their life (which is limited by the durability of the capacitor electrolyte and it's related seals more than anything else, under normal usage) regardless of how many power on/off cycles you give them - remember the capacitor is doing maximum work 100 to 120 times per second continuously under normal operation in a full-bridge configuration! The diodes don't really care about dv/dt for inrush - the current loading at startup is only the capacitor inrush.

So the reason you find so little information about this supposed tradeoff is that it doesn't exist - well designed power supplies do not stress their capacitors on inrush, and thus they are not affected significantly by any reasonable number of power cycles - reasonable in this case would be in the millions of cycles, typically, over the device lifespan. If you're plugging and unplugging or switching on and off your Nord millions of times, the switch, socket, cord, or connector are likely to wear out before the power cycles have a meaningful impact on supply life.

Again, this is true for quality supplies - this is a normal consideration for the design of the supply and any competent engineer will make sure that several cycles a day is orders of magnitude below the threshold of affecting the lifetime of the supply compared to the normal aging factors. It is not true for cheapo (read, most any basic computer power supply from Asia) supplies - which use underspecified capacitors and cheap electrolytes, among other problems, in my personal experience. These are also usually switchmode designs which tend to be much harder on the capacitors as their continuous-duty dv/dt is higher than the linear capacitor dv/dt - effectively they turn on and off their supplies several thousand times per second. So their capacitors wear faster, even under normal operation, making them more vulnerable to inrush damage over time. But this is a separate issue and does not apply to Nord-style supplies anyway (and good switchmode designs overcome this, anyway, but they're more expensive).

[dhbp-nord]

Line conditioners in my rack. No issues. Not horrifically expensive either.

D.

[PScooter63]

My specific situation in the US is, I’m more concerned with surge suppression than power outages. Any of Tripp Lite’s Isobar models does the trick for me. Relatively pricey, but they are designed to not fail as readily as cheaper competitors. In fact I’ve never seen one fail, and I still have the same ones I purchased 15 years ago (I bought my most recent one 4 years ago).