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Using Eco Mode in phoenix inverter with complex startup profile smallish loads

I understand that Eco mode pulses the inverter output for a short period and looks for an increase in load in response to determine whether or not to fully power one. It also appears that Eco mode can cause problems with high inrush loads such as compressors. My question pertains to its use will relatively low power loads such as TVs or other electronic devices with sleep (low power) modes and longer duration power up cycles.

A TV, for example, will power up into sleep mode and await a subsequent power on command from the control panel or a remote control; the power sensed by the inverter may not reach the minimum detection threshold. It seems like Eco mode is not well suited for loads with any sort of internal power consumption intelligence - you need something like a light bulb hooked in to the same circuit to provide a power draw that is sufficiently high and of the right type to be reliably detected.

My specific case is for a TV of about 20-60W with a 3-5W sleep mode on a Phoenix 12/250 or similar inverter. My hunch is that this would not work with Eco mode.

Does anyone have any experience with this use case?

Phoenix InverterVE.Direct
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2 Answers
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mosswings answered ·

Capacitors do initially look like a short circuit when fed a step function voltage pulse. Then they decay to an open circuit. The amount of current that will go through the capacitor will be limited only by the impedance of the driving circuit - and an inverter has very low output impedance. Inductors do the opposite - they look like an open circuit and then decay to a short circuit.

It does sound like the Eco mode was designed for heavier, more robust loads than modern electronics provide - and in any case electronics with power management or sleep circuitry would both drive and be driven nuts by the inverter's constant searching.

The other way to switch an inverter on with a load is to backchannel the inverter switchon with something like a universal remote - pressing ON on the TV would initiate a sequence of commands - first, inverter on; then, TV on, and so forth. Could even draw less power than Eco mode.

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Thats easy, they have a remote function. It comes bridged but you can pull it out and do whatever you want with it.

ripper avatar image
ripper answered ·

I stopped tests quickly because the needed minimum load is fairly high and higher than I can produce with efficient LED lights. I lit up my whole house and it wouldnt come on. But I have a TV that comes on after a power outage no matter what, that was enough load to keep the inverter on (stupid TV). So nothing gained. I run it solely with a fridge, that works.

With a TV I would be more concerned about reports of burned out electronics. As I understand it, the test pulse charges capacitors at basically short current in any charging and voltage regulating device ie TV, Laptop, phone charger, most everything electronic thats plugged in. They then discharge as mandated by electricians code of ethics and get charged shortly after again. Usually this happens only once evertime you plug it into a wall socket. So like ten times over the lifetime of a TV. Here it happens hundreds or thousand times a day. Eventually some little part from the cheapest vendor lets out the electric smoke it needs to run. A non electronic fridge doesnt mind eco mode from the voltage spike perspective, a too small inverter however might struggle to recover from the surprise to finally finding a willing drain. Any hesitation and the compressor stalls. At best it needs three times the power while being stalled than eco mode saved you beforehand, at worst the compressor motor burns out if that happens regularly.

I struggle to find actual use for this mode.

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