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Transfer Switch (IOTA-50R)
#1
Posted 02 March 2012 - 11:45 AM
#2
Posted 02 March 2012 - 12:48 PM
BUT, I do check all screws on ATS and 120 VAC breaker panel as part of the annual inspection.
Absolutely, a loose connection causes resistance, which produces heat.
I have no idea (and won't speculate) on whether there are other problems with the switch.
But, a loose connection on any brand ATS will, under high loads overheat!
Brett
Dianne and Brett Wolfe
1997 Safari Sahara 3540
Moderator, FMCA.com Forums
Chairman, FMCA Technical Advisory Committee
Member, FMCA Long-Range and Development Committee 2007-2009
Moderator, http://www.dieselrvclub.org/(FMCA chapter)
#3
Posted 28 March 2012 - 12:08 PM
When the original automatic transfer switch (ATS) failed due to (allegedly) defective brushes on the power cable winder in 2006, it was replaced with the IOTA-50R in 2007 under warranty service. Also damaged was the inverter/converter. The original ATS had a loud hum, which was very annoying when trying to sleep as it was located in a compartment under the bed! The IOTA didn't have that problem.
In 2009, the cable winder brushes again failed with resulting destruction of the inverter/converter, the front standard definition TV set and a DISH HD receiver. The ATS was said to be okay by the repair shop but I had the power winder permanently removed as this appeared to be the 2nd time that this happened.
During a heat wave in 2010 in north TX when we were living in the coach full-time, the ATS started overheating. When the air conditioners were on, the wires on the ATS heated up to over 400 degrees using a laser pyrometer! The insulation was melting on the ATS and the plastic cover was warped. The breakers never tripped inside the coach. The long wait for a service appointment during that vacation season caused me to purchase a new IOTA-50R through ebay and installing it myself, which was not that difficult. I was unable to unscrew the old terminals - they were very tight slotted screws and the screw slots were unable to tolerate twisting them off. Cutting the electrical cables from the ATS was the only way to get them off. The cables were fried and oxidized anyhow, all on the power grid side, NOT on the generator side (everything worked okay with the genset). Fortunately they weren't aluminum and there was just enough slack to connect them to the new ATS. The terminal screws on the new ATS were of the allen wrench type and were much easier to torque. The smell of burning plastic and insulation remains in the power cable compartment to this day but the new ATS seems to be functioning okay. Whether the ATS failures caused the power winder brush failures or the other way around is uncertain. When the last IOTA failed, there was no power winder to blame.
If the IOTA ITS-50R is defective, what model ATS would be a suitable replacement? I would like to have one on hand.
#4
Posted 28 March 2012 - 10:32 PM
have the RV Safety Recall Notice for the IOTA ITS-50R Transfer Switch.
Safety Recall: 11V-577
Safety Advisory: 11-170
#5
Posted 09 May 2012 - 12:09 PM
We had a similar situation arise last March with a Monaco Coach that had a burned up Iota inverter. At that time there weren't any recalls but, two is enough for me not to trust the integrity of this manufacturer.
Again, as an electrical contractor, we are researching possible replacement units and we will recommend once we have found something that is trusted.
#6
Posted 09 May 2012 - 12:20 PM
Welcome to the FMCA Forum.
Were you able to determine the cause of the failure?
Clearly any resistance can cause heat, which degrades the part which leads to more heat......
A wire, not properly secured with the screw at the factory might be one such source.
Brett
Dianne and Brett Wolfe
1997 Safari Sahara 3540
Moderator, FMCA.com Forums
Chairman, FMCA Technical Advisory Committee
Member, FMCA Long-Range and Development Committee 2007-2009
Moderator, http://www.dieselrvclub.org/(FMCA chapter)
#7
Posted 09 May 2012 - 09:19 PM
Www.powermaxconverters.com
#8
Posted 01 August 2012 - 10:41 PM
Since then, using a replacement IOTA ATS, all was okay until traveling back home to Texas 2 days ago. In Missouri, it was over 100 degrees and we were using the roof airs and, thus, the genset, while traveling. While entering a rest stop, the genset suddenly cut off. I restarted it and all seemed to be okay.
Later, at the campground, I smelled burning plastic from the shore cable compartment and sure enough, the ATS had melted. This time, it was on the genset side and involved one leg of the hot and the neutral wires. On shore power, there were no problems and the wires stayed cool. We drove home the next day using only the engine A/C, which barely kept it more than 5 degrees cooler than the outside. I later noticed that the front Dometic Duo-Therm heat pump AC compressor would only stay on and cool for a few minutes, while the rear one worked fine. The ACs are on different hot supply lines and it was the front AC line that overheated when using the genset.
Did compressor lock-ups cause the ATS wires to melt? If so, why didn't the breaker on the genset or the load center trip first? In the meantime, the front AC is scheduled for professional service and I installed an ESCO ES50M-65N ATS (I had purchased it just in case after reading about the IOTA problems) which works fine in both genset and shoreline modes without any overheating of the wiring, although the generator would not kick in with both ACs activated at the same time - I had to switch in one AC at a time. Also, the ESCO has an audible 60 cycle hum, which the IOTA doesn't. Oh, well...
#9
Posted 02 August 2012 - 09:56 AM
This may explain the heat buildup.
#10
Posted 27 October 2012 - 05:54 PM
I am calling Monaco Monday to get their reaction.
#11
Posted 27 October 2012 - 06:10 PM
Welcome to the FMCA Forum.
When you started smelling the hot electrical smell, did you check the tightness of the connections in the ATS? Loose connections are the #1 cause of problems in ATS's and 120 VAC breaker boxes.
A VERY good idea to spend 10 minutes once a year and check all connections in ATS and breaker box (of course with shore power, generator AND inverter OFF).
Brett
Dianne and Brett Wolfe
1997 Safari Sahara 3540
Moderator, FMCA.com Forums
Chairman, FMCA Technical Advisory Committee
Member, FMCA Long-Range and Development Committee 2007-2009
Moderator, http://www.dieselrvclub.org/(FMCA chapter)
#12
Posted 27 October 2012 - 08:03 PM
Your post is certainly accurate but it sure makes it sound like you are blaming what is likely a faulty piece of hardware on the victim!
#13
Posted 27 October 2012 - 08:26 PM
I do lots of mechanical inspections on coaches. Loose connections/screws in the ATS and 120 VAC breaker box are reasonably common. And as you know that leads to heat which leads to more resistance which leads to more heat........
Should an owner make this 10 minute job part of their annual inspection-- IMO YES. Not sure about blame, but the vast majority of these issues are very preventable.
Vibrations going down the road (particularly the state of today's roads) makes checking the connections/screws very important.
So, not a lawyer's answer as to who is to blame, but from a practical standpoint, it is easy to substantially minimize the issue. Been doing this on my coach for over a decade. A well-spent 10 minutes.
Brett
Dianne and Brett Wolfe
1997 Safari Sahara 3540
Moderator, FMCA.com Forums
Chairman, FMCA Technical Advisory Committee
Member, FMCA Long-Range and Development Committee 2007-2009
Moderator, http://www.dieselrvclub.org/(FMCA chapter)
#14
Posted 27 October 2012 - 08:36 PM
I full-time. When am I going to do this and where?
This is not a battle so we may just have to agree to disagree, but if there is something as critical as a transfer switch which requires periodic attention, this should have been brought to the attention of the owner and the transfer case should have a huge warning label that user intervention is required.
#15
Posted 27 October 2012 - 08:58 PM
Yes, we are getting deeply into philosophy. Many do not believe in doing Preventive Maintenance-- some, including myself do.
And, over the years, I have found the 120 VAC components (ATS and 120 VAC breaker box) to be a high enough chance of failure to invest the time in PM'ing them.
But, then I spent today replacing unbroken parts on Dianne's dad's car-- 9 year old serpentine belt, transmission fluid, filters, etc. Yes, this was still while the car was running properly.
Dianne and Brett Wolfe
1997 Safari Sahara 3540
Moderator, FMCA.com Forums
Chairman, FMCA Technical Advisory Committee
Member, FMCA Long-Range and Development Committee 2007-2009
Moderator, http://www.dieselrvclub.org/(FMCA chapter)
#16
Posted 27 October 2012 - 09:08 PM
#17
Posted 27 October 2012 - 09:31 PM
#18
Posted 27 October 2012 - 09:40 PM
#19
Posted 28 October 2012 - 06:55 PM
Charles & Sheila Pennington
"Maddie" our golden retriever & "Gracie" our westie
2004 39' KSDP
'03 Jeep Liberty
#20
Posted 31 October 2012 - 05:41 PM
I have more than 30 years in the electrical field, and more than 20 years in RVs.
My iota-its-50R failed to transfer from the genset to shore tie on a leg of our trip across northern Nevada on a day that was running in the range of 85 to 90, not particularly hot for our area. I disconnected the shore tie leads from the ATS and coupled the leads to have shore tie power for that night.
The next morning I put things back to normal on the ATS and the transfer to the genset went fine. There was no electrical smell or damaged wiring. The failure to transfer was the only problem at that time. The first experience was repeated the next day when I shutdown the genset. The transfer went to the inverter just fine, but again, when I went to transfer to the shore tie, the ATS failed.
I dealt with this problem for 4 days, then changed to another brand of ATS, and have had no problem since.
Now, I do not feel that electrically inexperienced people should be checking connections, breakers or anything else behind the safety panels of the boxes, ATSs or anything like that at all, ever.
I do feel that with connections like the Iota-its-50R that have aluminum connectors you must have them inspected occasionally. Checking the entire coach's electrical system for loose connections, etc., should not take more than an hour. All the normal connector materials, whether aluminum, copper, silver or anything else, are exposed to expansion and contraction due to the heat caused by variations in amperage. The heating / expansion may, over time, cause connections to loosen up. Most of this is a non-issue, as the equipment is designed to accommodate the variations. (i.e. how often do you check the connections in your house breaker box). There is one factor we deal with in our motorhomes, that is vibration, which can cause some problems. Again, though I ask, how many of us check the breakers, fuses, or wiring connections in our cars and trucks. I feel the manufacturers of the equipment, and the motorhome manufacturers are responsible for the assurance the devices are installed properly and work with the design limits.
My Iota-its-50R apparently had a relay that failed. That was good for me, but could have been a prelude to the more extreme meltdowns and wiring failures others have experienced. I cannot agree with the assumption that the coach manufacturers installed them incorrectly, as though there are clearly a number of coaches with the problem, not enough to blame them. I am very much of the opinion, the problem is in the design, assembly or components used in making the switch.
I very strongly feel that the suggestion the problem is due to users not checking the connections is simply wrong.
Bill
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