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Transfer switch questions

Well, here we go.
My transfer switch does not seem to be working. Right now when I plug into shore power (tested), nothing lights up on the monitor. If  I unplug and crank the genet, the monitor lights up and we have juice. If I turn the inverter switch on, the microwave comes to life.
I have read up on the past forums, and studied the Beamalarm site, and from what I can gather, the ATS is just not doing it's thing when it comes to shore power.
Several questions.
1. from what I gather in my 99 U270, the ATS should be a Magnatek ATS-100. would that be correct?

2. The ATS should be under the bed. Is that accessible from the bedroom side, or do I need to lift the bed?

3. Am I looking for a galvanized metal housing ?

4. Once disconnected from shore power, and inverter and genset off, do I open the steel case to check the points.?

I will be tearing into this tomorrow and it would be nice to have some idea of where I am headed.

Thanks for your help.

Len & Deb

Re: Transfer switch questions

Reply #1 –
1.  Our ATS was also the ATS-100.  We replace it a couple of years ago when we had no power to any 110 vac outlets.  We found our replacement at a local RV supply store while traveling in Montana.  We removed and replaced ourselves whit the help of FoFum members.

2.  Our ATS is under the bed and is accessable when the bed is lifted.  Our ATS is in the left front corner.

3.  It is a galvanized box with wires coming into and out of it.  you should be able to follow wires to the breaker box also at the foot of the bed.

4.  We lifted the cover off of the box and tested the legs with a multimeter.  First the left side then the right.  Then we shut down the power and tested again.  We found that power was not passing through the ATS.

We were fortunate that we had help and support from a very knowledgeable member and he talked us through the process.  Hopefully one of our "magicians" will step up and help you out.

Good luck.

Re: Transfer switch questions

Reply #2 –
You do have to lift the bed to find the ATS, witch is in a silver aluminum case, but could be galvanized. The point is, it is a natural metal color, not painted on our coachIt is a good idea to disconnect all AC power when pulling the cover off of the switch. You can then see two sets of contacts inside the box. At that point, If you're careful, you can turn on the shore power and with a noncontact meter preferably, you can see which set of contacts are shore power by checking the input side, which is on the right in our coach, also a 1999 U270. At that point, I would disconnect the shore power, and then you can have a look at the points. You could also have somebody outside turning on the shore power breaker while you observe the points to see if there is any arcing. It sounds like they're stuck in the off position, and possibly a light rap with a rubber mallet on the outside of the case might free it up temporarily. There have been some threads on the form about replacing the points inside the switch, But I think most just replace it. Whatever you do, just be very sure there is no AC power present when you are poking around inside the box!
Don

Re: Transfer switch questions

Reply #3 –
Quote from: lenspeiser –
Well, here we go.
My transfer switch does not seem to be working. Right now when I plug into shore power (tested), nothing lights up on the monitor.

When you say "tested" did you verify you have voltage at the coach end of your shore power cord? Just to be sure your shore plug, cord, coach connector, and cord reel if you have one...are good...

Re: Transfer switch questions

Reply #4 –
Allright! Thanks for all the replies. I will attack this tomorrow and probably be back at the keyboard for more advise.

Ya'll have a nice evening.
Len

Re: Transfer switch questions

Reply #5 –

Another possible solution you could consider, if you enjoy "taking the road less traveled": eliminate the ATS entirely and use a manual switch.  I went this route, and we have been very happy with the result.  The installation is not complicated, but does require some (very) basic electrical knowledge, relocating and bending some big wires, and making a hole in the end of your bed base.  See photos below:

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Re: Transfer switch questions

Reply #6 –
Thanks again to everyone for their helpful input. Turns out after I got into this that the PO had installed a Surgeguard 41260 and a 34560 TRC power protector ATS.
I followed your instructions and found I had power to only one leg at the input on the surge protector.
I went back to the outlet and sure enough, it had both legs.
Then I took the plug, moved the spades back and forth, reinserted it, and voila! Juice!
I have gotten a replacement plug, and am installing it tonight.
When the ATS decides to finally throw craps, I am interested in the manual switch that Chuck and Jeannie suggested. I just need to get better schooled so I know how that affects the rest of the system.

Many thanks again!
Len

Re: Transfer switch questions

Reply #7 –
@Chuck I too like that manual switch. Can you give some details on operation? Like can you switch while hot?

see ya
ken

Re: Transfer switch questions

Reply #8 –
Ken,

While you can switch under load, it WILL pit the points.  So, in this regard, no different than the ATS.  The manual switch is simpler and what you will find on most marine applications.

Re: Transfer switch questions

Reply #9 –
Quote from: kenhat –
Can you give some details on operation?
Like Brett says, it is always a good idea to reduce the loads to a minimum before switching AC sources.  I had this habit impressed on me early in our RV learning curve, and have practiced it religiously.  That is one of the reasons I believed the ATS was, for me, unnecessary.  If I am going to the trouble to manually turn everything off, why do I need a "automatic" AC switching device?  For me, it makes more sense to simply add one more step to the change-over process.

As to operation - could not be simpler.  The switch is 3 position, so you simply select the desired source, or "OFF" when neither is available.  Since you can only select one source at a time, you can be plugged into 50 amp shore power, and simultaneously have the generator running!  This allows great flexibility in managing your power sources.

Typical scenario:  It is summer - HOT - we pull off the road into a camp ground with the generator running and roof air going...the switch is on "GEN".    I park/level the coach, then go outside and plug the coach into shore power.  Go back inside, turning the A/C units off as I go to the bedroom.  In the bedroom, with all (big) loads now shut off, I shut down the generator at the remote panel.  Then I turn the manual switch to "SHORE", and we again have AC power available.  Then, if desired, I turn the air conditioners back on.  SIMPLE!

Another BIG advantage to the manual switch: it is absolutely silent!  My wife and I were both particularly sensitive to the "humming" noise made by the ATS when plugged into shore power.  Coming from under the foot of the bed, this noise was constant, and (to us) very irritating, especially at night when trying to sleep.  I believe installing the manual switch was worth it for this factor alone.  Happy Wife = Peaceful Life!

We have actually eliminated both of the original factory transfer switches in our coach.  Soon after I installed this manual AC switch, we added a complete PV system to the coach.  Since the Magnum MS2812 inverter we used has automatic switching between inverter/charger function, and automatic "pass-through" of AC power source, the original inverter transfer switch was unnecessary, and was removed.

Re: Transfer switch questions

Reply #10 –
While on this subject, I have an additional question.  Our coach is a 1999 40ft U295.  There are two identical transfer switches.  One is used for shore power or generator power.  The other is used for the inverter.  Both are 50A units.  My question is why did Foretravel use a 50A unit for the inverter.  This seems like TOTAL OVERKILL to me.  There are only 3 minor 20A circuits powered by the inverter and the power wire from the inverter to the transfer switch is only  common 12-2w/G.  Max load on a 12 gauge wire is 20A yet is connected to a 50A transfer switch.  Also note that the internal connections in the 50A switch are designed for two No. 6 gauge hot wires in each circuit.  There are NO wires connected to the second "HOT" post on any of the terminals. 

It would seem to me that a 30A switch wired with 10-2w/G would be more than safe considering the load on the inverter. Any thoughts on this ?  Oh yea, Should have started off by saying my Inverter transfer swirtch is bad and has to be replaced!!

Nick

Re: Transfer switch questions

Reply #11 –
I agree, no need for a 50 amp ATS from inverter unless you need two separate hots (very unlikely).

Also, be aware that many inverters and inverter/chargers have built-in  transfer switches.  So, if contemplating replacing the inverter, may be able to eliminate the additional ATS.

With the built in ATS, you have power from main breaker box to inverter.  When inverter sees 120 VAC, it "passes through" power to circuits that can be powered by the inverter (hopefully through a sub-panel) AND if an inverter/power, also charges the battery.

Re: Transfer switch questions

Reply #12 –
Being a newbie at this, I am wondering why Nick wouldn't use the 50 amp ATS to fix his problem, and then put in a 30 amp ATS or manual switch to handle the inverter?
Len

Re: Transfer switch questions

Reply #13 –
I just read own through all this again and discovered that Nick's INVERTER ATS was what had failed. If it had been the other way around, could he have switched to make his shore power usable?

Re: Transfer switch questions

Reply #14 –
Quote from: Nick Cagle –
While on this subject, I have an additional question.  Our coach is a 1999 40ft U295.  There are two identical transfer switches.  One is used for shore power or generator power.  The other is used for the inverter.  Both are 50A units.  My question is why did Foretravel use a 50A unit for the inverter.  This seems like TOTAL OVERKILL to me.  There are only 3 minor 20A circuits powered by the inverter and the power wire from the inverter to the transfer switch is only  common 12-2w/G.  Max load on a 12 gauge wire is 20A yet is connected to a 50A transfer switch.  Also note that the internal connections in the 50A switch are designed for two No. 6 gauge hot wires in each circuit.  There are NO wires connected to the second "HOT" post on any of the terminals. 

It would seem to me that a 30A switch wired with 10-2w/G would be more than safe considering the load on the inverter. Any thoughts on this ?  Oh yea, Should have started off by saying my Inverter transfer swirtch is bad and has to be replaced!!

Nick
Before changing anything, retrace the circuit. We also have the second transfer switch. It is fed by 6gauge on a 50 amp breaker from the main panel and by 10 gauge from the inverter. The 12 gauge from the main panel to the inverter is for the charger, not for pass through. For us, the OEM design gives 50 amps to the inverter subpanel on shore or gen, 30 amps on inverter.

Nick

Re: Transfer switch questions

Reply #15 –
A big "THANKS" to Chuck for his posting re: manual transfer switch.  When mine started acting up in various ways I decided it was time to replace it.  I ordered the exact one.  It was pricey, but doing away with the "WTH?" effect was well worth the price.  Now I will no longer wonder what state the switch is in.  I'm with Chuck - the process of incrementally shutting down all loads, then transferring manually - and positively - then incrementally adding loads back, is one I much prefer.  I live and work full time in the coach - and for those appliances that are better left running (network and computer equipment) I have true sine wave UPSes anyhow, so they are unaffected.  I am not going to post pictures - they aren't as pretty as Chuck's...  :D  But I will say that I took BOTH ATSes out as Chuck did ultimately when he got his solar installed.  I wish that my solar installer (AM Solar) had discussed the option with me prior to their work in April.  In any case it's done now and I have the peace of mind that follows from having things exactly as you prefer them to be.

The hardest parts of the job were to figure out the modifications made during the solar install, and then mounting in my coach was complicated because it has full thickness plywood covered with carpet instead of a thin wood veneer in the bed base, so I had to chisel out some relief in order to reduce the thickness so the selector knob could be mounted.  The space to work in is very scant, but it can be done with some patience.  Finally, the heavy gauge wire can be a challenge to secure without stripping the holding screws, but again, patience (despite the hour and the need to get electricity back on) works wonders.

Re: Transfer switch questions

Reply #16 –
If  the  manual transfer switch being that is being discussed is installed, how does that installation affect the AUTO-START generator capabilities?

Re: Transfer switch questions

Reply #18 –
Quote from: Chuck & Jeannie –
Another possible solution you could consider, if you enjoy "taking the road less traveled": eliminate the ATS entirely and use a manual switch.  I went this route, and we have been very happy with the result.  The installation is not complicated, but does require some (very) basic electrical knowledge, relocating and bending some big wires, and making a hole in the end of your bed base.  See photos below:


I  like this idea.  Could you give us some specific info on the switch and where you found it?  Webeen turned off the CB at the park's hook up every night before turning in on our last trip.  Hum isn't tolerable.
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Re: Transfer switch questions

Reply #19 –
After coordinating with Chuck last winter I picked mine up from Defender

http://www.defender.com/category.jsp?path=-1|328|2290051&id=2290059

Defender.com select electrical-then switch- then selection switch.  Having a problem with link copy


They are Marine but usually have good prices.