Buying a New Inverter
This is my first post and I want to say a huge thank you to all of the knowledgeable people who donate their time to make this forum such a great resource! I have been researching and reading for weeks and have learned a great deal thanks to you.
However, there are a few questions I haven't been able to find answers to...
The general consensus is that buying a good quality inverter is worth the investment, and I would like to take that advice. However, my application is an off-grid one-room cabin and the inverter and batteries are in the living space. I might have guests who could be bothered by the hum of the inverter, so I thought it would be best to buy a high-frequency, switching type that doesn't have the big transformer. I read somewhere that most of the noise comes from the transformer and that the high-frequency ones are quieter. However, it would appear that the better inverters are generally the low-frequency type.
After all my sizing research, I concluded that a 3000W inverter would be a good size, give or take. Most of the time, the loads won't be more serious than things like coffee maker, toaster, hair dryer, laptops, vacuum, and a TV. The fridge and stove will be propane, and no washer/dryer. The biggest concern is the well pump which is currently 24VDC. Its pushing the limit with the total head, but it does manage to fill the pressure tank to 50 PSI or so. However, the flow isn't great and down the road I may need to upgrade to a 1/2HP or 3/4HP pump on 120 or 240VAC. If the inverter I buy now can't handle the surge for a normal well pump motor, it looks like I might be able to get a Grundfos soft start pump to work. My other idea is to buy an inverter with stacking capability, so that I could add another one later to get 240VAC if needed.
Here are my questions:
1) Is my concern about the inverter noise valid? If you were sleeping 8 feet from your inverter, would you go the high-frequency route? (Turning it off probably won't be an option. It will probably need to be in search mode at least.)
2) What are the best brands of high-frequency inverters?
3) In general, are high-frequency inverters more efficient with low power loads (laptops & lights) than low-frequency inverters?
4) The only high-frequency inverter I have found with stacking capability is the Cotek SD3500-124. Is Cotek a decent brand? Does anyone have this inverter and like it? Does the paralleling/stacking feature work as expected?
5) If I had two stackable inverters, I should be able to combine a 120V leg from each inverter to get 240V for the well pump and still use the 120V legs to power house circuits, right?
Thanks for any help!
0 · Share on Twitter