Deal on Pure Sine Wave Inverter

[tialiden]

Hey all, I seem to have located a good deal on some Pure Sine Wave inverters from reliable inverters marketed under WZRELB (and probably other names as well). I find them on Amazon and eBay and have tested their 12v 2500w/5000w peak on smaller loads. Seems to be fine, but feel free to weigh in.

Anyway they have a sale on their site and ship direct (I'm in the US) for free.
Special deal says get extra 20% off their price in cart after adding code:
5sm3v7j4k2zp
Says sale is good 1/15/2021 to Jan 25th and good on 12v and 24v 3000w models.
That makes the 12v model about $276!

https://reliableinverters.com/colle...ure-sine-wave-inverter?variant=19844490002545

 

[snoobler]

I have the 24V/2kW WZRELB. Fine for what it is. I still have it around in case I need emergency power.

Consider that those units have no meaningful surge that lasts beyond milliseconds. If you're starting something with an electric motor on it, it may be challenged.

 

[tialiden]

I was running a recipricating saw and florescent lamp and charging a rechargeable light while running a slow cooker crockpot on high, didn't phase the 12v 2500w model. Only had it a month though.

 

[snoobler]

Non-saw loads were probably less than 500W, so you had 2kW reserve. Recips are among the most friendly electric motor applications with their large mechanical advantage and low rotating mass.

Things like fridge, air compressors or A/C compressors are the brutes. My unit couldn't handle the surge on a 3/4hp jet pump... I didn't realize how beastly the surge was on that due to the high rotating mass of the impeller.

 

[Hedges]

Non-saw loads were probably less than 500W, so you had 2kW reserve. Recips are among the most friendly electric motor applications with their large mechanical advantage and low rotating mass.

And brush-type "universal" motor.
And variable-speed trigger.

Variable-speed is (almost) the ultimate "soft-start". It is a chopped piece off the tail of sine wave; optimum would be a reduced-amplitude sine wave for universal motor, reduced frequency and amplitude for 3-phase induction motor.

 

[tialiden]

Do people have tricks to help with high draw applications like your well pump? For example can you implement some AC capacitor on the output side of your inverter or something? Sorry if an ignorant question.

 

[snoobler]

There are soft start types of devices that limit peak current. These are pretty common for A/C systems.

https://www.microair.net/products/easystart-364-3-ton-single-phase-soft-starter-fo

Easiest for me was to get a bigger inverter. My Victron Quattro 48/5kW (4kW continuous, 5kW 30 min, 10kW 20 seconds) just giggles at it.

 

[Delmar]

I have a 48V 2500W unit and it works to my satisfaction as a backup inverter. It does struggle with my 1/2hp garbage disposal but will start it. No problem with the fridge compressor. I would not recommend if you are off-grid and want power 24/7.

One caveat is the live neutral on some units. You can measure 60V line-ground and 60V neutral-ground with 120V line-neutral. I measured this phenomenon on mine. Click here for more conversation.

However when I bonded the neutral to my breaker panel, the inverter still works properly with no smoke emitted. In my (admittedly ignorant) opinion the 60V neutral is merely an ungrounded floating voltage and will not pose a problem.