EG4 18K - Air Conditioning won’t run without grid

[trdstarlet]

@AW1511 did you get this resolved?

 

[Texas-Mark]

You should get a MicroAir Easy Start.

While he did not say what brand, he did say he has a soft start.

 

[Dyotat100]

Needs to be micro air 368-72

I tried the one SS sells and it wouldn't start when I was getting higher start amps.

I'm usually around 33 amps now with 4t. They also changed my firmware. I was on 1717 before what I have now. I also have no grid input at all

 

[Kant_Hack_It]

Copied from another thread.

So, we were having the same issue. I noticed the yellow arrows were feeding power to the EPS rather than standard consumption. I'm not sure what the EPS stands for but by reading what I did it was meant to be hooked up to a critical loads aka backup panel. Following the flow charts in the manual gets it set up this way.

What we did to fix it was turn OFF off grid mode. This moved the arrows to consumption mode rather than EPS. I don't know why EG4 labeled it the way it did, but EPS mode does not like very high inrush current. By switching this, we went from an 18kpv that wouldn't even start a 2 ton ac to one that would not only start the two ton, but start a 4 ton on an easy start with the 2 ton running and about 2k worth of normal loads.

I'm not sure how it'll work without grid connection but I would think it would do the same.

In brief, if your 18kpv won't start ac even with micro air soft start, turn OFF off grid mode.

 

[ksmithaz1]

While he did not say what brand, he did say he has a soft start.

A normal "soft-start" is an extra capacitor that is connected to the motor to provide more current to the start winding in the motor during the initial start, that is removed once the unit starts to keep from burning up the winding. Staring current is only reduced nominally. MicroAir actually limits current flow.

I did the same thing with a thermistor, actually worked pretty well, but during the summer would not stay off long enough to cool down. I was going to build something with a thermistor and a bypass contactor on a delay, but for $300-odd the MicroAir just seems to work. Their tech support was great as well.

 

[Texas-Mark]

A normal "soft-start" is an extra capacitor that is connected to the motor to provide more current to the start winding in the motor during the initial start,

You are referring to a hard-start. The OPe'r can clarify, but I'm pretty sure he has a soft start based on his LRA measurements after installing it.

 

[TonyInMemphis]

Here:

https://eg4electronics.com/backend/wp-content/uploads/2023/09/EG4-14.3kWh-PowerPro-WallMount-AW-Spec-Sheet.pdf

Recommended settings.

Then I showed my math, which may be wrong, but this is where i got it from.

trash the soft start a get a HARD START more kick to start the compressor. larger capacitor more bang for the $$$$ most older trane unit come with them preinstalled.

 

[Texas-Mark]

trash the soft start a get a HARD START more kick to start the compressor

Wrong answer if trying to not overload an inverter.

 

[EG4TechSolutionsTeam]

@AW1511 did you get this resolved?

I requested the troubleshooting ticket for this issue, and it appears the problems were resolved following the installation of a new soft starter and adjustments to the settings.