Power inverter woes

Harley

Expert Expediter
I just had my third inverter in 4 years burn up. I have no idea what causes this but I have used the same brand each time and the company has replaced the first two under warranty. I told them that their inverter should have some kind of fuse to prevent them from overloading but it seems to fall on deaf ears so I am searching for a different brand. They tell me that it is suppose to have thermal protection but seems it still fails. It is a Cobra 2550. I was wondering what kinds of inverters others use. I'm open for suggestions.
 

Turtle

Administrator
Staff member
Retired Expediter
What happens with these things is, the fan goes bad, stops working. The inverter isn't overloaded, it just bakes itself to death. Heat kills electronics and it's critical to keep them cool. If the fan stops working, replace it ASAP. Depending on where the inverter is mounted, you may be to create additional cooling for the space.
 

guido4475

Not a Member
Even though I am not a big fan of inverters bigger than a 400 watt continuous/800 watt peak, I have had great luck with my Sima brand from the Petro.3000 watt cont./5,000 watt peak.It was awesome.I only used it to power my apartment sized fridge in the truck while going down the road. The gas generator powered it while sitting.
 

chefdennis

Veteran Expediter
As Turtle said, it is a fan issue. I am on my 2nd one in 2 yrs and the fan is getting noisy now...I have a 2500 watt Power Bright and a 1500 watt Cobra as a backup in the toolbox just waiting to be installed....i am really thinking of spending the long dollar and getting a good Samlex "pure sine" inverter...hopefully that will take care of the issue of burning up the fans in the lesser espensive units.....
 

greg334

Veteran Expediter
Chef, I'm curious, what does the pure sine wave thingy have to do with the fan?

You all know the fans can be replaced?
 

Harley

Expert Expediter
The fan in my inverter was still working when it went up in smoke. I was not running any more than usual appliances. My fridge is always on and when using the microwave or coffee maker I crank up the engine to give it extra juice. This has always worked in the past. When not cranked and the juice is getting low it always had the alarm go off so I could crank up. Whatever it was I am thinking could have been avoided if it had a fuze of some kind. I called Cobra this morning and they said the automatic thermal shutdown was all that was in my inverter. At any rate it is out of warranty. I will not buy another one but need to find something today. Turtle what kind do you have running your stuff? I think your fridge is bigger than mine but I thought a 2550 would be plenty big enough.
 

Turtle

Administrator
Staff member
Retired Expediter
I'm running a POS Cobra 1500 Watt inverter. I have a 3000 Watt pure since was inverter, but a nut came loose inside and it fried. Need to get it repaired or replaced. Been saying that for 4 years now, tho. The Cobra works fine. About every other year I end up having to replace it, mainly because the fan isn't working, or even if it is the unit has just been too hot for too long and becomes toast. That's just what happens to inverters that are on 24/7 and have a relatively high amp draw (more than 5 amps) nearly all the time. No amount of fuses will prevent that. The high dollar inverter tend to be designed for more strenuous applications, like running 24/7 with constant draws, tho.

I got the 3000 Watt inverter specifically for a couple of things we needed a mobile inverter for out on the farm, mainly a circular saw and a couple of other things while doing some fencing. But here in the truck 1500 Watts is plenty. The Microfridge pulls like 150 Watts, and the microwave pull 900 Watts (when the microwave is on, the fridge's compressor automatically shuts off). The computer, lights, fan, Espar heater, satellite receiver and TV along with the fridge and anything else I've got going don't come close to 1500 Watts. With everything running at once, except the microwave, the most I've pulled is 25 amps, which is 300 Watts. I've also got a 120V AC Dirt Devil vacuum which pulls 9 amps at 120Volts, which is 1080 Watts, and I've used that a time or two with several things running without any problems (the inverter squealed a few times, indicating an overload, but quickly goes silent after the vacuum gets running).

It's really hard to overload and burn out these inverters, because they have a built-in overload protection, same as the under-voltage protection where it screams when there isn't enough juice (if you wait until your inverter screams before cranking up to recharge batteries, you're just killing you batteries by discharging them too deeply, but I digress since that has nothing to do with the inverter).

Whether you get a cheap POS inverter or a really high dollar really high quality pure sine wave, the chances are it's the same cheap fans that keep them cool. A high end inverter (or laptop of desktop computer) might have an $8 cooling fan, and a cheap inverter might have a $3 fan. The primary difference in the price is fan speed, not necessarily fan quality or longevity. My 3000 Watter has two $5 fans, and I had to replace both of them after about a year.
 

chefdennis

Veteran Expediter
Being a pure sine vs the modified sine has no bearing on the fan at all. The thought (and no it is no a for sure thing) is that with the higher quality unit, the componets might be a bit better, thats it.

The main reason for going to a pure sine is more that I am having an issue with my laptop while it is being powered off the inverter.

As for replacing the fans, tea i am aware that they can be replaced. But again, that doesn't fix the issue I am having with my laptop when it is powered by the inverter.
 

chefdennis

Veteran Expediter
have had one for 2 yrs and 190,000 miles . problem started about 6 months ago and is there with and without the filter..had the filter checked and was told it was ok...and they could have sold me a new one, its not a warranty issue, i was ready to buy a new one...
 

chefdennis

Veteran Expediter
I fixed it...seems that while I had enough voltage and wattage and ampreage from the "home bank" and inverter...the issue was not having a "steady" voltage" flow to the laptop...with the frig cycling and the fan going and the alarm/radio all and the TV/DVD all drawing there was enough change in the flow of the voltage going to the laptop that is was causing the erratic cursor movement...

The fix...a small 150 watt inverter just for the laptop...no more problem....:D
 
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