Why is the power level on my furnace (Blower) cycling when viewing Emporia energy sensor?

[rtasker]

I have a EG4 6000xp that connects to my furnace blower motor (120v) through a protran 2 transfer box. When viewing the power readings of the Emporia energy sensor that is connected to the furnace circuit breaker in the main panel the power readings seem to by cycling up and down when the Transfer Switch is connected to the Gen (6000XP). When the TS is connected to Line (Grid) power the readings of blower is very stable. There is no L1/L2 power connected to the 6000XP only the neutral and ground wires running from the main panel’s ground/neutral bond. Why would power readings be cycling so extreme when running off of the 6000XP, but looks very stable when running off of the line power?
Not sure what this could mean.
Running off 6000XP

Running off of line (Grid)

 

[Quattrohead]

Does the blower sound different when running from the inverter ?

 

[rtasker]

I haven’t noticed notice any sound or performance between running it off of the inverter or the grid.

 

[Gib]

Wondering if your neutral is floating (ungrounded), when utility is switched off.

 

[AZ Solar Junkie]

Wondering if your neutral is floating (ungrounded), when utility is switched off.

It shouldn't be - that transfer switch doesn't touch the circuit's neutral or ground, so they would still be connected to neutral and ground in the main panel. Only the hots lines are switched. So when on Line the circuit is getting the hots, neutral, and ground from the main panel. When on Gen, the circuit is getting the hots from the 6000xp, but the neutral and ground is still coming from the main panel. With the neutral and grounds also connected from the main panel to the 6000xp, I wouldn't think that would create a problem.

 

[rtasker]

Wondering if your neutral is floating (ungrounded), when utility is switched off.

The ground/neutral bond on the 6000 XP is disabled, because the ground and neutral buses are connected directly to my main service panel, which is bonded ( neutral/grounded ). I’m trying to avoid multiple ground neutral bonding points in my system. I was told common neutral architecture of the 6000 XP will work with the ground neutral wires only running into the main service panel.

 

[EG4_Jared]

I have a EG4 6000xp that connects to my furnace blower motor (120v) through a protran 2 transfer box. When viewing the power readings of the Emporia energy sensor that is connected to the furnace circuit breaker in the main panel the power readings seem to by cycling up and down when the Transfer Switch is connected to the Gen (6000XP). When the TS is connected to Line (Grid) power the readings of blower is very stable. There is no L1/L2 power connected to the 6000XP only the neutral and ground wires running from the main panel’s ground/neutral bond. Why would power readings be cycling so extreme when running off of the 6000XP, but looks very stable when running off of the line power?
Not sure what this could mean.
Running off 6000XP
View attachment 200217
Running off of line (Grid)
View attachment 200218

I would recommend examining the loads to ensure that there isn't a line imbalance contributing to this issue. Ideally, not exceeding 3000 watts per leg would be optimal in this scenario.

 

[Gib]

Sounds right to me.

I missed terminating the Emporia blue wire to neutral when I reinstalled mine. ( I don't like the jack's on the Emporia. Also, I ended up skipping every second input on the unit because I thought there was some signal interference.

The only other thing that I can think of is to check all the terminations for a bad connection.

 

[Hedges]

Check frequency stability.

Induction motors draw current according to rate of slip from line frequency. It is a flywheel, and if driven above 60 Hz then frequency drops below, it would draw nothing until it slowed down or AC frequency picked up again.

A generator, we could imagine governor causing it to surge.
Inverter, would expect stability from crystal timebase.
But maybe power quality varies the injected power due to voltage or waveform shape fluctuations, varying the amount of RPM vs. frequency slip.

 

[mciholas]

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 the Emporia power to the inverter and see what that does. Bet that or something like that fixes it.

If you want to measure power in two domains, you really need two Emporia devices so each stays phased with the power it is measuring.

Just a guess...

Mike C.

 

[rtasker]

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 the Emporia power to the inverter and see what that does. Bet that or something like that fixes it.

If you want to measure power in two domains, you really need two Emporia devices so each stays phased with the power it is measuring.

Just a guess...

Mike C.

Thanks Mike, you are correct my Emporia unit is powered by the grid and the blower is being powered by the inverter when I am getting the cycling display. Do you think I can just move the Emporia's red and black wires from my main panel and connect them to the Black(L1) and Red(L2) load terminals in 6000XP just to see if the chart display changes? If you are correct about the current reading from the inverter's loads beating in and out of phase on my display, then this is more of a setup (wiring) issue with my Emporia unit and not my 6000xP installation?
Thanks again.

Robert

 

[Quattrohead]

Yes just connect your emporia to the output of the 6000 XP and try again.