May 5, 2017

CNBOU inverter first tests

CNBOU comes out clean

Pure clean wave form. Nice.

We are huge fans of the European inverters. Still, the world’s manufacturing is improving fast. With a real cost difference, we thought it might be a good idea to test one of the Chinese contenders.

Introducing the CNBOU inverter test

First flight: Burn in.

For a day we burn in the inverter. Burn in involves turning your piece of equipment on and leaving it for 24-48 hours. The CNBOU passed!

We then added loads. Initially we added a 25 watt CFL light fixture load. We ran it for 24 hours. The inverter passed!

We then added a 750w resistive load (heater) to the test. We turned on the CFL light. CFL lights are notoriously sensitive and tend to flicker with bad wave forms. We turn the heater on and off. No flicker. We run the heater for an hour. No problem.

Another PASS.

We then turn the resistive load to 1500w. Still no noticeable change other than that the inverter begins to run the cooling fan. Not full time but 5 seconds on 30 seconds off. Neat.

Now we start to “hit” the inverter with an inductive load complete with startup surge. We turn on and off a 7.25 amp blower motor.

Note: 1500+870=2,370 total load without the surge

Another PASS.

Flight Two:

Now that the inverter has been tested and burned in we are ready for install. We install the inverter at our test facility (aka the “camp”) and let it run solid for two weeks. During this test period the inverter must run a modern fridge. A smoothie maker (900w). A dishwasher (heating the water electrically). Pumps, coffee makers, stereo equipment, routers, wifi, device charging. All the day to day demands of off grid living. It must run 24/7.

PASS.

Flight 3:

So the next to last stage. Test the “idle load” and the wave form. Off to the rocket scientist to get an oscilloscope.

Idle load: 9.6w! That’s astounding.
A two kilowatt inverter with an idle load of 9.6w. Wow.

If you know inverters you know “idle load” is a key feature. You see your inverter runs 24/7. So everyday that 9.6w will translate into 166 watts of power you need to get into your batteries.

9.6 is world class for inverters today.

To put this in perspective. Some of the older style inverters use 35w on idle. Now you need to put 840 watts every day into your batteries.

So, imagine its been cloudy for three days. Which inverter do you want to own. The one that used 2.5kw just to be on. Or the one that used 500w. The one that has saved you 2kw of power.

Yup. That’s why we give the CNBOU 2 wings up on this test!

PASS with an A GRADE!

Wave form:

Wave form. One of the knocks on the lower cost inverters is wave form stability. So we setup the oscilloscope and had it ‘er.

Pure clean wave form. Nice.

Here is the wave form under a 140w load.

As you can see the wave form is beautiful. In fact it’s smoother than the wave form we were getting off the grid.

PASS with an A GRADE!

Final flight:

The final test is time. This is a variable we cannot manipulate, speed up nor slow down. So far the time input is three weeks. So drop back as we update this variable. Smile.

What we can say is that the new inverters from China, and in particular, CNBOU, are wonderful quality. We wish them the very best success.

Kelvin

Tagged on:

Leave a Reply