30FW Transfer Switch Issue-Shore and Generator

[thudd3r]

Camped for the first time this season about 2 weeks ago. used an extension cord plugged into the garage (15a) for a couple of days prior to cool the fridge and then used shore power at the campground (50a) for the 3 days we were there...all was well

RV has sat since then until tonight. plugged it in to the garage with the same cord and outlet (15a) and the transfer switch will initially connect and then the voltage drops to about 100-105v and the transfer switch disconnects.

Thinking i have an issue with the power in my garage (all 15a circuits), i tried the generator. Transfer switch clicks over correctly but then the voltage starts dropping to the point the transfer switch disengages, just like it was on shore power

Any ideas? the 2 red lights on the transfer switch are lit, which i believe shows we have power on both legs.

 

[Judge64]

Certainly odd that you are seeing the voltage drop that low on both shore power and the generator.

Where are you measuring the voltage? At the input or the output of the transfer switch?

What happens if you tun the main breaker off in the Power Control Center and there is no load on the transfer switch? Does the transfer switch stay engaged?

If you see the voltage drop with the main breaker off, then something in the transfer switch may be causing the voltage drop and be the source of the problem and need replaced.

 

[thudd3r]

thank you for the reply Judge64. I will give it a try with the main off.

i have been monitoring it through the firefly input voltage display and have tested it at the end of the cord. end of the cord without a load shows a steady 120 and the firefly display (remoted by the transfer switch as i understand it) shows 120 initially but then drops over the course of less than a minute to right around 100 where it disconnects.

planning to take the cover off and test at the input of the transfer switch this morning

 

[thudd3r]

BLUF: possibly due to the batteries were trying to charge off of the 15a/120v/single phase input and the inverter was just in a "weird" state. not sure what fixed it but reloading inverter defaults seemed to contribute to the fix

Turning off the ac breakers/loads was great advice Judge64

Once I disconnected all of the loads the AC would stay on and stable, with the transfer switch connected both through shore or generator. Closing the circuit breakers one at a time, everything stayed stable until I got to the inverter out, then the voltage would dive, forcing the disconnect

Looking at the firefly panel controls for the inverter I noticed 2 things...1) it was registering 0 V in, but 120V (fluctuating) out and 2) it was trying to charge the batteries.

Not knowing if the inverter settings were correct (most of them are blank like they have never been set), I loaded the defaults for the inverter. After that, and after making sure the battery charge was turned off, stays stable. The input voltage to the inverter still fluctuates between 1V and 60V, but I assume that may be because I am on a 15A single phase circuit. This is probably also the reason why turning on the battery charger drops the voltage so bad...but I would think the inverter would disable the charger instead of dropping the voltage so low...maybe that is one of the settings that is not set

 

[Judge64]

Glad you are making progress and eliminating some things......

So I am not familiar specifically with the 30FW and don't know whether you have a Converter / Charger and Inverter or just an Inverter / Charger but I will offer this as well.

If you have an Inverter / Charger, make sure the Charging settings are set to the proper house battery type you have installed i.e. Wet, AGM or Lithium.

If your Inverter has a built-in ATS, it should not be doing anything when you are on shore power. But if it is an Inverter / Charger, the AC will passthrough the Inverter but the Charger will be trying to charge the house batteries. If they are deeply discharged, there could be issues using only 15A service if the charger is trying to use a high charging amperage.... like 100+ amps.

If you have a Converter / Charger and it is a 60A or 80A Charger, it could also be drawing a lot of AC power from your 15A service if your house batteries are deeply discharged.

 

[thudd3r]

Appreciate the continued help...we have a MagnaSine inverter/charger. I did check after loading defaults to make sure the battery type stayed on LFP. The batteries are over 13.7 and that is where they were at when I enabled the charger earlier this morning and it pulled the voltage down. Even though the batteries were at 13.7, it went into bulk mode, so it was pulling the most power. Right now the inverter is in passthru and the charger is disabled, so the internal ats is just routing the ac through and monitoring, but not charging.

I am reading through the inverter manual to get smarter on it, also going to reach out to Brian and see if they have something detailing the inverter settings

 

[bclemens]

This is what I got back from engineering.

Before they added the Lithium option we would select “Custom = Absorption 14.6, Equalize 14.6, Float 13.8” along with battery bank size. Now with the Lithium option we just select Battery Type and battery bank size. I don’t think we’re doing anything with the “low batt cutout” or Absorption time”. The Magnum remote has these default at 10vdc low batt cutout and 1.5 hrs absorption time. I took a picture of what I would start with. I think the Low Battery Cutout is probably something best tailored to a person’s lifestyle.

 

[thudd3r]

Thanks Brian. I cant actually access that screen...maybe because I have LFP selected so it is applying a set profile. I will check for a custom option.

With the current settings, the Firefly wont accept any changes I make to the limited available inverter settings (low battery cutoff, max charge current, audible alarm, etc.). My unit didnt come with the optional inverter display so I cant access many settings, but the ones I can access wont save

to add to the story...

Generator or Shore power (currently 120v 15a) if the charger is not disabled it will switch to bulk charging and draw the voltage down to the point the transfer switch disconnects.

The batteries are right at 13.7, the solar chargers are in float, and the Victron display shows 100% (13.65)

The inverter is set to passthru and the charger disabled. The physical inverter status light goes out completely, but I believe this is simply because the 5W minimum power draw isnt found during the search (I am only running the fridge)

 

[Judge64]

to add to the story...

Generator or Shore power (currently 120v 15a) if the charger is not disabled it will switch to bulk charging and draw the voltage down to the point the transfer switch disconnects.

the batteries are right at 13.7, the solar chargers are in float, and the victron display shows 100% (13.65)

The inverter is set to passthru and the charger disabled. The physical inverter status light goes out completely, but I believe this is simply because the 5W minimum power draw isnt found during the search (only running the fridge)

I dont believe this is related, but the firefly wont accept any changes I make to the inverter (low battery cutoff, max charge current, audible alarm, etc.). My unit didnt come with the optional inverter display so I cant access many settings, but the ones i can access wont save

Just for the heck of it...... try changing the Shore Power Breaker size to 15A.

That is supposed to tell the Charger the maximum power capable based on the shore power breaker size. It would be interesting to see if it throttles back the charger and stops your issue.

But I'm not hopeful since you said the same thing is happening on the generator, which should have plenty power available.

It sounds like there is a much larger power draw on the charger than there should be or even a short for it to cause such a large voltage drop that the ATS is cutting out.

 

[bclemens]

Good call...engineering added the following (along the same lines).

"If he backs down his shore breaker size to 15A when plugged into the garage that should help out. He also can lower his percentage of charge rate. That will also throttle back the charger."

 

[Judge64]

Good call...engineering added the following (along the same lines).

"If he backs down his shore breaker size to 15A when plugged into the garage that should help out. He also can lower his percentage of charge rate. That will also throttle back the charger."

Thanks for confirming that's the way it should work. I was pretty sure but always good to get confirmation!

 

[thudd3r]

I was able to select the "Custom" battery type...



It comes up with some pretty crazy values, which i can adjust, but they wont save...they just revert to the defaults shown here

i also have this screen...



I have adjusted the vac dropout to 80VAC, but it just keeps going back to 255VAC

Should I try an inverter internal reset? It states to remove all AC/DC power..I assume unplugging AC, leaving generator off, and flipping the battery disconnects is sufficient?

 

[Judge64]

I was able to select the "Custom" battery type...



It comes up with some pretty crazy values, which i can adjust, but they wont save...they just revert to the defaults shown here

i also have this screen...

I have adjusted the vac dropout to 80VAC, but it just keeps going back to 255VAC

Should I try an inverter internal reset? It states to remove all AC/DC power..I assume unplugging AC, leaving generator off, and flipping the battery disconnects is sufficient?

So even when depress and hold the Save Icon it won't save your setting changes? That seems odd.

At this point I would try a power cycle..... i.e. remove both AC and DC power for 5 minutes and then reconnect to see what happens.

 

[thudd3r]

appreciate the continued help...keeping me from going crazy...

i lowered the shore breaker both on the main power and on the inverter control...same result unfortunately. I was able to get a few of the setting to hold. shore breaker size and low battery cutout will save, but low battery cutout reverts to 12.8 if the transfer switch activates due to the low voltage

here are the current settings...



this configuration works as long as the charger remains disabled. generator also works

in the following configuration the charger will kick on and set to bulk, dropping the voltage below 90 and throwing the transfer switch



inverter settings



anything blank or unknown will not save

i can select the output voltage and frequency (120/60) but they wont save



i can adjust vac dropout (tried 85), auble alarm (set to on) and transfer mode (tried appliance), but it wont save the settings



i can select and adjust all of these, but only the low battery cutout volts will save. actually havent tried recovery level, but have not idea what it should be set to

 

[thudd3r]

So even when depress and hold the Save Icon it won't save your setting changes? That seems odd.

At this point I would try a power cycle..... i.e. remove both AC and DC power for 5 minutes and then reconnect to see what happens.

press and hold doesnt seem to do anything...the second i lift my finger it switches to the inverter screen and the green status light flashes really slow for a few seconds then goes green solid

i even tried to change the color scheme (thinking maybe the button colors were messed up in this theme) but when i went back to the inverter screen it had changed the cutout voltage back to 12.8...sigh

 

[Judge64]

If this happens when running the generator, then something else is causing the voltage drop and the ATS to cut out.

It would seem you already narrowed it down to the Charger since I believe you said earlier that you disabled it and the ATS stayed connected.

I would try power-cycling the Inverter / Charger as we discussed previously.

If it continues to happen after power cycling the Inverter / Charger, there could be an issue with it.

 

[Judge64]

press and hold doesnt seem to do anything...the second i lift my finger it switches to the inverter screen and the green status light flashes really slow for a few seconds then goes green solid

i even tried to change the color scheme (thinking maybe the button colors were messed up in this theme) but when i went back to the inverter screen it had changed the cutout voltage back to 12.8...sigh

That cutoff voltage should be when the Inverter shuts down. It should have nothing to do with the ATS.

 

[thudd3r]

thanks Judge...i disconnected the ac and turned both the solar and house disconnects. will report back

 

[thudd3r]

well that didnt work unfortunately.

 

[Judge64]

The only other thing I can think to try is.......

You mentioned your batteries look to be fully charged. It is normal when first turning on a Charger that it will analyze the batteries and could quickly go through Bulk and Adsorption before getting to Float.

Since you seem to have this isolated to a Charger issue, we are assuming the batteries are not the issue. If we would want to eliminate the batteries, I might try hooking the Charger to another 12V battery..... even if it is a Wet or AGM battery (changing the Charger Battery Type first if needed) to see what happens.

If you had a short in a battery cell, I would not expect you to see 13.6V with them not being charged or any load on them. But if there was a short in a cell, perhaps that would cause a large demand in current when attempting to charge them.


When you have two batteries connected in Parallel, a bad battery can sometimes be masked by a good battery. I had this happen a few months ago in my Jeep. Every now and then the Jeep wouldn't start and it acted like a dead battery. I would charge the battery and put a load tester on it and it would test ok. After this happened a few times I remembered there was an auxiliary battery for the AutoStop function. When I disconnected the battery cables from the starting battery and put the load tester on it, the battery failed. Put a new starting battery in and all has been well since.


If you hook up another battery and this still occurs, I have to think it is a problem with the Charger itself.

I can't think of any setting that would cause such a large AC voltage drop that the ATS disconnects.