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HVAC averages 2500 KWH per month, rest of building is 6500 KWH per month (lights, computers, equipment). The demand charge is due to HVAC units randomly being on at the same time, and maybe some piece of equipment (like the 5 KW temp chamber). This is more likely to happen in the summer than...

So you purposefully made the manual requirement harder than what was necessary just to appease some AHJs? That seems dumb. The manual should be the actual requirements. If an AHJ says 2 ft and you see 6.75 inches in the manual, you have more room to argue for 12 inches. In other words, you...

The trademark is Alpha & Omega Semiconductor, aosmd.com. Send the picture to them for identification. Full part numbers are rarely printed on the parts these days. My brief search suggests it is an AOT400, datasheet attached. That part is obsolete, though these folks have some surplus...

I bet your Emporia unit is powered by the grid and the blower is powered by the isolated inverter. This causes the Emporia main unit to phase to the grid and not the inverter, so the current readings for inverter loads slowly beat in and out of phase leading to the chart you displayed. Move...

Yotta Energy for putting battery storage under the panels on the roof. There is no worse place you could possible put the battery than the extreme temperatures and exposure of the roof. The heat will chemically aged the cells quickly, the cold will reduce their capacity, and the thermal...

There is no true "free market". China subsidizes its companies dumping below cost to drive out competition. Even in the USA, we provide incentives and other help to companies. The real question is who pays for tariffs? The supplier or the consumer? It seems to be a tax by another name...

If that was true, regen on EVs would kill the battery in about one thousand miles since every stop light or stop sign is a charge followed by a discharge. The only polite thing to say about that tech support guy is that he isn't in engineering. Mike C.

From the EG4 manual: The rear bracket does not appear to be design to support the entire weight of the battery (282 lbs). This install appears to use that bracket and there doesn't seem to be any support under the battery. Even the units near the floor appear to have their feet removed and...

For the ardent brand loyalists, they will pay that, but that will be a small market given the advent of sub $3000 options out there now. Mike C.

https://www.alarmgrid.com/faq/what-is-the-difference-between-etl-listed-and-ul-listed "In the United States, all Nationally Recognized Testing Laboratories (NRTLs) are required to follow the same testing procedures and maintain identical standards. Whether a product is tested and approved by...

"The tariff rate on semiconductors will increase from 25% to 50% by 2025." Think about what this means for a USA based company designing electronic products. You can build those devices in the USA with imported parts tariffed at 50%. Or you can build those devices in China (or other Asian...

Please lookup RMS (root mean square) voltage. https://www.electronics-tutorials.ws/accircuits/rms-voltage.html 240 VAC driving a resistive load has exactly the same power delivery of 240 VDC driving that same load. The example they give happens to be exactly 240 VAC. "For example, the...

I would be interested in specific example cases of this, where an insurance company came to investigate a fire, found some non listed device, and on that basis alone, denied coverage. I'm not against advocating for quality and certified parts, but I despise the sales tactic of spreading FUD to...

Cap rated 105 C and 2000 hours isn't fantastic but may not be as bad as it sounds. First, that lifespan is at full ripple current. If operated at less, lifespan increases. I don't know if there is a mathematical way to compute that, but even if there was, we don't know how much ripple current...

It all comes down to what the utility saved from the customer export. A KWH pushed into the grid at your meter is not a KWH used by another customer, they get less due to losses in the wires, transformers, etc. If the power can be used nearby the efficiency can be pretty high, well above 90%...

Use Google Earth or Maps (in sat view) to see what south aligns to on your property and use that as a reference. Do not depend on a compass due to variation in magnetic versus true heading, and the fact compass are subject to local variations. The sun at clock noon doesn't really work due to...

For using the 200 amp pass through for the entire house, that's all fine if the grid remains up. The inverter produces up to 10 KW, the grid makes up the deficit. If the house needs less than 10 KW, you can export to the grid the excess you can make. If the grid fails, then the entire house...

Why not? The key is that you need to use twisted pair wires, the twisting protects the signals from external noise. My assessment is that should work electrically. Power frequency is so low the loss in the cable will be minimal. For example, the EG4 18KPV manual says the CTs can be extended...

Higher voltage is less cost, less size, less weight, less losses. Some components will get more expensive, but the savings in other parts of the design make up for that and more. This is why you won't find any EVs operating at 50 volts. If lower voltage was better, they would be using it, and...

My company building is 35,000 SF single story located in Newburgh, IN as shown here: After looking into residential solar for my parents in Florida, I've started to think what I can do to my building, so I am perhaps going slightly mad thinking about solar. The building is 3 phase 208 VAC...

https://www.whirlpool.com/blog/kitchen/what-is-induction-cooking.html Basically the range is the primary of a transformer, the pan is the shorted secondary, so the electric energy transfers through a magnetic field and heats up the pan and cooks the food. Mike C.

That's stupid. At the moment of grid failure, the likely outcome is the inverter will be overloaded with the current loads (nothing switched off) and thus the inverter will fault out. You get effectively no backup as grid failure causes inverter failure. There is also the issue that the...

Assuming you have standard 24 VAC discrete thermostat controls (not RS-485 communicating ones), then: Divide your units into #1, #2, and #3 priority. You need a relay that closes when #1 turns on, another relay that closes when #2 turns on. Then run #3 turn on signal in parallel through the...

This is tin foil hat talk. The utility grid frequency is VERY tightly controlled. The utility is not going to shift it for some solar inverters. That would screw up people's clocks and the phasing of all the utilities power sources, including the interconnection of other grids across a wide...

That usually means they didn't pass FCC conducted emissions (electrical noise on the wires) with the filtering internal to the unit. The classic treatment for that is placing ferrite/toroid on the lines that exit the unit. Units which don't have that didn't need it to pass. This is why you...

I'm going to postulate that there are cases where the potential output of the 18KPV exceeds what the utility agreement is and the utility wants a hard, non user settable limit that they can positively assure won't be exceeded. For example, Florida Tier 1 agreements limit output to 10 KW AC and...

PV arrays are commonly strung to 400-500 volts instead of the common per panel voltage of 50 volts. This is because PV wires are long and the cost for heavy gauge wire would be excessive. This is the same issue with batteries, we just accept it due to short cables. But it sure would be nice...

One nice thing about QO breakers is that you can get them with various features and accessories. It has a lot of versatile features. Available in GFCI, AFCI, and combination of both? They got that. Want two circuits per slot? They got tandems (panel has to be compatible): Want key...

You should have a bypass option so you can run the critical loads panel from grid directly while isolating the inverter. A relatively simple way to do this is an interlock breaker in the critical panel. The grid feeds the main breaker which is usually off, the inverter feeds the inverter load...

Short answer: it is highly likely to be okay for small magnets. A large static magnetic field can lead to saturation of inductors and transformers. When this happens, they lose their ability to store energy in the variable magnetic field. So putting a big magnet on an inductor can disrupt the...