Thor electrical problems

[smitty1020]

We have a 2018 Thor windsport 29M. The Ac's in the ceiling cut out even if one is on and the ac lights go on and off, get dim and then real bright. We have had the inverter replaced because of a defect. Even with a new inverter it still happens. Any suggestions as to what i'm dealing with.

[EA37TS]

Inverter more that likely has nothing to do with the issues. First, check the electrical connections in the ATS.

[16ACE27]

Originally Posted by smitty1020

We have a 2018 Thor windsport 29M. The Ac's in the ceiling cut out even if one is on and the ac lights go on and off, get dim and then real bright. We have had the inverter replaced because of a defect. Even with a new inverter it still happens. Any suggestions as to what i'm dealing with.

When you say "the ac lights go on and off........." what lights are you talking about? The illumination lighting in the MH is DC powered.

When you say "inverter", do you really mean CONVERTER?

The converter takes 120 VAC from SP or the generator and creates 12 VDC to power DC loads in the MH and charge the batteries.

An inverter takes the 12 VDC from the batteries and creates 120 VAC to power SELECT AC loads like a residential fridge and TVs. Unless your MH came from the factory with a residential fridge your probably don't have a factory installed inverter.

[smitty1020]

I did say the AC lights not the DC Not a residential refer. But I do have a factory installed inverter. But thank you for your input.

[Chuck and Mary Ann]

Here is what we have found with the dual units in our 2018 36.1. One unit is he maser and one is the slave. In our set up the slave must be turned on second and off first. So on the FireFly - and this may take a couple of tried to figure out which unit is which, but start the master unit first and then the second unit. the lights may settle down when you figure this out - but also check all the wire nut connections in the metal boxes for strong contact and protection. Beyond this I have now other advice for you.

[16ACE27]

Originally Posted by smitty1020

I did say the AC lights not the DC Not a residential refer. But I do have a factory installed inverter. But thank you for your input.

Indeed you do because you also have the outside kitchen with the 120 VAC fridge. But your inverter is not involved in your current issue.

Seems you have two simultaneous symptoms:

The DC lights dim and surge
The running A/Cs "cut out"

It might help to better define what you mean by "cut out"
Both fan and compressor turn off? For how long? Do they immediately restart?
How long does this event take? Half a second? 5 seconds?

The A/Cs actually require 12 VDC from the DC buss to operate. This "control power" comes from the DC buss (the same DC buss that powers the interior lighting) through the furnace, to the thermostat to the control relays for the A/C's. The DC controls the AC. So if you momentarily loose this DC control power the running A/Cs will power off.

So I suspect you have an issue that is dragging down the DC voltage on the DC buss causing the lights to dim and the A/Cs to loose the DC control power.

This could be caused by placing a large load on the DC system if the house batteries are disconnected (USE/STORE switch in STORE) or if the house batteries are at their end of life.

There is a possibility that the inverter is suddenly being overloaded by a fault in the inverter output. But if on SP the inverter shouldn't even be used.

[smitty1020]

My DC lights are not effected just the AC side dimming going bright and shutting down the air conditioner. A little C 4 may help the problem

[lwmcguire]

Originally Posted by smitty1020

My DC lights are not effected just the AC side dimming going bright and shutting down the air conditioner. A little C 4 may help the problem

Ace laid it out pretty well

What do you mean AC side of what?

[Bill Johnson]

Originally Posted by smitty1020

We have a 2018 Thor windsport 29M. The Ac's in the ceiling cut out even if one is on and the ac lights go on and off, get dim and then real bright. We have had the inverter replaced because of a defect. Even with a new inverter it still happens. Any suggestions as to what i'm dealing with.

Maybe the one AC unit has a problem and is drawing to much power. Like with a home AC unit sometimes the lights in the home will flash when the compressor turns on. Maybe there is a problem with the compressor in the one AC unit. I would check the 120 volt connections and make sure they are clean and tight. Even check by taking off the wire nuts and make sure the wires are all the same length. One wire might have 3/4 inch of copper showing and the other might have only a 1/4 inch under the wire nut causing a bad connection. Check the back of the fuse box and make sure the wires are tight and not burned or corroded. If the compressor was bad I would think the breaker would trip. They make replacements for wire nuts that work great, wago lever nuts

[16ACE27]

Originally Posted by smitty1020

My DC lights are not effected just the AC side dimming going bright and shutting down the air conditioner. A little C 4 may help the problem

What AC lights are you talking about "going bright" or, as per your OP "ac lights go on and off, get dim and then real bright"?

I've already told you the lights in your RV are DC lights. If they only come on when you have AC power then you have house battery issues.

[Beau388]

Come on guys -
AC is the abbreviation for Alternating Current
A/C is the abbreviation for Air Conditioner
In my coach, all the interior and exterior lights are 12 volt Direct Current.

[smitty1020]

I stand corrected Both A/C ‘s cut out even if one is running and the VAC OR AC powered lights and outlets running lamps and such dim then go bright the DC lights are not affected at all It was suggested it may be the ATS
Thanks every one for your support this is SO THOR

[Hooligan2]

Sounds like ac input.. The ATS connections or dirty contacts would be a good place to start..
I assume (that has not worked well so far) you are plugged in at a pedestal.

Do you have the same problem on the genny? Power cord?
Or on another pedestal?

[smitty1020]

Always at a pedestal. Never on the generator boon docked
For a week A number of pedestals through 14 states. Have very good surge protector Buying this used is always a chance it really looks like it had gone through a power surge at some point hmmmm

[Hooligan2]

May be worthwhile to try on the generator. That would eliminate the power cord and possibly the surge protector (depending on how it is wired- my surge protection is inline between the pedestal and the ATS-- but not in the generator supply to ATS)
Using the Generator also switches the contacts in the ATS to the generator side.

[CHS]

With your setup, it would probably make sense the install a soft start on both units. WAY less amp draw on startup. I have a 4000 generator and used to draw down when they came on. Now I cannot even tell when the compressor kicks in.
I tried both brands and personally like the Micro-air brand. Also the Micro-air is UL listed. I do not see a UL stamp on the SoftstartRV brand.

https://www.microair.net/products/ea...r-conditioners

https://youtu.be/1mCeNRODDxc

[lwmcguire]

Originally Posted by smitty1020

Always at a pedestal. Never on the generator boon docked

For a week A number of pedestals through 14 states. Have very good surge protector Buying this used is always a chance it really looks like it had gone through a power surge at some point hmmmm

Have you checked the transfer switch?

[smitty1020]

Well look what we have here I'm still a little new at this. New ATS arrives tomorrow. Thanks to all for your amazing support

[Bill Johnson]

Originally Posted by smitty1020

Well look what we have here I'm still a little new at this. New ATS arrives tomorrow. Thanks to all for your amazing support

Glad you found that and it didn't start a fire

[Nancy W]

Originally Posted by smitty1020

We have a 2018 Thor windsport 29M. The Ac's in the ceiling cut out even if one is on and the ac lights go on and off, get dim and then real bright. We have had the inverter replaced because of a defect. Even with a new inverter it still happens. Any suggestions as to what i'm dealing with.

Check your electrical wires, Romex wires in ceiling area going through a metal knock out hole to AC unit itself. My 2021 Hurricane 29M had the plastic bushing come out. This allowed the Romex wire to rub through to the wires inside. It caused an Arc fault were it didn’t blow the CB right away. Instead it went on and off until it eventually burned itself dead. Very scary the burn scare it made before actually dying. Never tripped the breaker!