Quantifying a power surge: Insufficient supplier-sourced knowledge

Portable power units have both instantaneous-output and run-time limits, of course, but this situation seems a bit ridiculous. Or, then again, maybe not. But how to tell?

Last December, a few hours after the “kickoff” of our high wind-induced multi-day power outage “adventure”, I had the bright (if I do say so myself) idea to try hooking up our portable power stations (plus extended batteries in two of the three cases):

to the refrigerator-plus-freezer combo in the kitchen, along with both its combo fridge-plus-freezer companion and a standalone chest freezer out in the garage. The weather outside, therefore also the temperature in the garage, was chilly, so I wasn’t terribly worried about anything spoiling in either of those latter two units. Then again, I didn’t know how long the outage would last, and I had three supplemental power solutions at my disposal, so…

A preparatory test-drive admittedly would have been wise

I started (and ended; keep reading) with the cooling combo in the kitchen, my highest priority for perhaps-obvious comparative ambient temperature reasons. It’s a Samsung model RF217ACBP/XAA; here are a couple of stock photos to start:

I dragged from the downstairs furnace room the EcoFlow DELTA 2-plus-Smart Extra Battery “stack”, enabled the former’s AC inverter outputs, and plugged the combo fridge-plus-freezer in. I heard the compressor start up (accompanied by a DELTA 2 front panel display-reported AC output spike)…try to start up is a more accurate description, because after a second or so, the setup seemingly overloaded and gave up trying. Next up, the DELTA 3 Plus and its Smart Extra Battery sibling. Same underwhelming outcome.

The wind was blowing, the outside light was dimming, and my spouse was understandably getting stressed, so I didn’t waste any more time messing around; I promptly bailed on the idea and focused my attention elsewhere. Since I’d already expended the effort to get both “stacks” upstairs, they ended up alternatively finding use in powering table lamps, recharging various battery-powered devices—lanterns, laptops, tablets, smartphones—and the like.

No, I didn’t bother trying to haul upstairs my even heavier SLA battery-based Phase2 Energy unit. And fortunately, save for the spoil-prone contents of our kitchen refrigerator (but not its combo freezer), we didn’t need to toss any food. Still, I was both disappointed and (more than a) bit surprised, because I’d seen success reports from other folks who’d successfully powered food-storage equipment (albeit of unknown capacity and for unknown duration) using EcoFlow and other suppliers’ similar systems in similar circumstances as mine.

Published data also would have been helpful

Given my background experiences with other startup-surge hardware, I was pretty sure I knew how the failure had happened, but not specifically why. So, after the electricity started flowing again, I did some research. First off, I realized I hadn’t enabled either EcoFlow base unit’s X-Boost Mode feature, which might have gotten them over the compressor-start initial-surge “hump”. Please take a moment to “enjoy” the following promo video clips :

As I wrote last February, X-Boost “doubles the output AC power (at a reduced voltage tradeoff that not all powered devices are guaranteed to accept, albeit obviously counterbalanced by higher current)”. Could it have helped? Dunno; I’ll have to try it sometime when I get a chance.

But how much surge current, and at what minimum voltage, does the Samsung RF217ACBP/XAA demand on compressor startup? Ay, there’s the rub. You won’t find it in the user manual, or even the service manual, only steady-state power draw specs. The labels on the side:

and rear of the Samsung RF217ACBP/XAA:

weren’t directly helpful either, although they at least revealed the compressor model number (MK162D-L1U SJ1). But my online browsing using that specific search term was equally fruitless.

Cue the hand-waving

What do online resources say in general? Here’s Google AI Mode’s take on the topic:

A refrigerator typically experiences a startup surge current 3–4 times higher than its normal running amperage, lasting only a few seconds. While running at 1–4 amps, it can spike to 15–30 amps during compressor startup. This inrush current is essential to overcome inertia, usually requiring a dedicated 15–20 amp circuit.

I just checked and confirmed that my kitchen refrigerator breaker is 20A. Feel free to contrast that with the “3.9 Maximum Amperes” claim in the above sticker closeup shot. Sigh.

Ballpark figures are better than nothing, I suppose, albeit still (quite) non-ideal. Am I just overlooking something obvious, or being pedantic, or is the startup surge draw:

useful information that
Samsung (at least) isn’t publishing

therefore, compelling consumers to potentially overshoot, buying portable power systems beefier and more expensive than they may actually need (and, apparently, than I bad-pun-intended “currently” own)? Reader thoughts are as-always welcomed in the comments!

My father (the King of Duct Tape) would have been impressed

p.s…while researching this post’s topic online, I came across a mind-blowing (at least to me) somewhat-related Reddit thread that I couldn’t resist sharing: “Fridge kept tripping circuit breaker until I added an extension cord. Why?”. Here’s my stab at the TL;DR summary:

The OP (original poster) eventually determined, in conjunction with his repair tech, that the refrigerator’s defrost heater was failing. But in initially attempting to debug the issue, originally assuming that the outlet wiring might be failing, he used an extension cord (beefy, I hope) to plug the fridge into another outlet, which worked fine. Turns out, the extension cord was still largely coiled and sitting on top of the fridge; the resulting added circuit induction sufficiently opposed the high frequency noise injection coming from the failing defrost heater such that the arc fault circuit interrupting (ACFI) breaker stopped tripping…temporarily, at least.

The entire thread is well worth your perusal if you have sufficient spare time and interest!

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

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