Recent content by mciholas

Complex question. The UPS wasn't designed to charge LFP to the right voltage exactly. it is close, but not perfect. Some LFP vendors sell batteries which claim to be "drop in" SLA replacements, so they either have added circuit changes to adapt the voltages or they are just boldly claiming...

I presume you mean watts. 1.8 KWH per day when operating on battery based on the above numbers. Mike C.

People casually refer to wall wart DC power supplies as "transformers". Just wanted to be sure that confusion didn't occur. The trim signal had to be AC to work. Mike C.

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...

I need to decide on rails for my 12 KW install on a W style concrete tile roof. Nominated candidate is the Ironridge XR-100 rail on 6 ft spacing using All Tile hook mounts. Ironridge also sells another kind of rail, the Aire A2 which would also work on 6 ft centers with the same tile...

How do you assure that? I thought the goal was a 2 pole relay, NC contacts to grid, NO contacts to inverter, it closes when the invert operates, drops when it doesn't. Seems like it would drop to NC contacts and that would be loaded with your AC circuits. Mike C.

The transformer needs to be AC just in case that wasn't clear. For 20 watt imbalance, it will take 83 mA through the wire. You can reduce this by winding the wire through the CT core more than once, say 4 turns, down to 20.8 mA. With 4 turns, a 6 VAC transformer with a 288 ohm resistor would...

There is no line switching. To repeat, my inverter will NOT drop a relay to bypass itself on failure. Or so says the reseller. I haven't installed it or tested that. Mike C.

No unsafe event has been described for a neutral loop that is 6 ft long. A redundant neutral connection sounds safer than using one neutral for two circuits. We have both quoted code and neither of us can make the system totally complaint with it. I can't avoid the neutral loop, you can't...

My inverter, on failure, will not drop a relay that connects GRID to LOAD automatically. Or so says the reseller. A relay is not simple, it turns out. Expensive, power hungry, complex to switch lines under load, etc. The DIN rail ATS I showed above would work nicely, but lacks US approvals...

This is getting ridiculous. Let's assume what I think you are advocating, a single point neutral bar with 3 connections: main panel, backup panel, inverter (combined grid and load neutrals into one wire). The neutral wire to the backup panel is only the loads on the backup panel, No problem...

This only works if the "inverter is down" detection logic works. If the invert fails such that it still energizes that relay, your backup panel is dark and the relay won't drop to grid. Ideally this means this relay is powered by the inverter AC output directly so there is no firmware or logic...

Not if the AIO fails. The ability to pass grid through the AIO depends on the AIO functioning to at least some small degree. Mike C.

Can I get this device in a UL version? Put this before the backup panel and have it automatically switch from grid or inverter. You can switch it to manual to force the choice, or it can be set to automatically switch on source failure. Rates 100 amps. Uses a servo motor, so not fast...

Correct. An illegal way to do this is to: 1. Turn off main panel main breaker. this disconnects you from the utlity. 2. Turn off every breaker in the main panel you do not want to power. 3. Turn off the main panel inverter breaker. 4. Turn on the backup panel grid breaker. 5. Defeat the...