Does anyone know power on surge levels for S9 models?

[Ameador1]

I am working on a remote power control system for my mines - mostly (and the most power hungry ones I'm running) S9 models. But I'm having difficulty finding the highest power surges they generate during power up so I can properly spec out my relays. I know +/- on the wattage for the general operating spec - but I'm looking for any quick, momentary surges that would hit the relays involved to make sure they wouldn't weld in place if undersized - but I don't want to just throw money at them for huge unnecessary capacities as they get overly expensive quickly using that approach. My multimeter cannot catch quick surges - it's not fast enough to pick up on those. Maybe an oscilloscope - but I don't have one of those. I've asked Bitmain support and explained what I'm trying to do - but they cannot seem to get what I'm asking and aren't giving useful responses.

Thanks!

[1714747994]

1714747994

[1714747994]

1714747994

[1714747994]

1714747994

[1714747994]

1714747994

[NotFuzzyWarm]

It is not the miner you have to worry about -- it is the PSU powering the miner. The 'plug-in' surge is dictated by the bulk filter capacitors on the line AC to raw DC side of the supply and the amount of that surge will vary with the make and size of the PSU. General rule of thumb is to expect the heaviest draw during the 1st 2 full AC cycles as the caps charge up and that can be from 5x up to 10x the continuous current draw.

For up to a 2kw PSU personally I'd use relays or better yet contactors (yes they are similar in function but are 2 different things: a contactor is designed with heavy surges in mind) rated for least 15 amps.

[Ameador1]

Hmmm - glad I asked. I had been primarily looking at 250v - 10A relays - but was just not sure that was enough to cut it. I will look into the contactors you suggest as well. I get the point of the surge being from the PSU - poor wording on my part - and obviously relevant. I am using all APW3++ PSU's - and one APW7.

Thanks!

[NotFuzzyWarm]

Oh, and if you want to measure powerline surges a 'scope is overkill unless you are doing detailed analysis. A multi-meter or amp-clamp that has a peak-hold function is all you need.

[Artemis3]

Oh, and if you want to measure powerline surges a 'scope is overkill unless you are doing detailed analysis. A multi-meter or amp-clamp that has a peak-hold function is all you need.

But if he has a digital scope lying around, let him post the pics! I want to see it too... Also from other newer models.

If you have a large operation with hundreds or thousands of units and there is a quick power fluctuation giving a quick off/on situation, that little burst a single unit does is multiplied... Would be nice to have an adjustable delay "protector" or such.

[mikeywith]

so i assume you are worried about "Inrush current" , i am not an expert in this field, but i know for a fact that Inrush current lasts too short that it will most likely go unnoticed.

speaking from a real life example, I run some of my S9s on voltage regulators, those indeed have a fixed wattage capacity, i had one of them almost 90% fully loaded, and not a single problem was faced,  breaker didn't trip, not a single fuse was blown.

i also agree with @NotFuzzyWarm in terms of using contractors instead of relays.