50A Surge Guard /Transfer Switch by TRC-2nd FAILED

[Larry and Heidi Lee]

For the second time within 2 years my TRC 50A Surge Guard Automatic Transfer Switch PN:40250 has failed. The original unit "smoked" while plugged in (50A) at a park in AZ during a 110 heat wave running both AC units, Fridge, etc. Just this past weekend nothing out of the ordinary, plugged into a KOA (30A) in Barstow and everything was fine but the park pedestal breaker popped twice when I tried to run a heat pump. I stopped using the heat pump and switched to the Hydrohot furnace. In this case I am using an adaptor to get 45A from a 30 A service. I realize this is not optimum but no 50A service was available. Anyway no problems at the park for the rest of our trip we continued to use park power with no problems. I get home and plug into our designated 50A service and nothing. No AC power being transferred into the coach. Using a multimeter I have confirmed power to the Surge Guard but no output to the coach. I suspect the PCB on this unit has failed. My question is this: Do I have a poorly designed transfer switch that will continue to require replacement or do I have a lemon? Can someone recommend a unit that has some reset capabilities or a little more durability? I dont want to purchase a third unit and continue to have these problems. Thank-you in advance!

[Edward Buker]

Larry,

I would talk to the engineering department at TRC and discuss the failures and see if they have some insight as to what conditions cause the fails and what you can do to avoid them. For instance the bay is usually hotter than the outdoors and at 110 outdoors the bay may be 120 degrees. Inside a sealed metal box with components and relay coils emitting heat might have put the unit well outside the design temperature operating window and had the components fail due to overheating.

If that is suspected you could cut several holes in the J box, on opposing sides, place a little filter material over one hole  and mount a computer fan over the other to constantly pull air in and extract heat out. This can only can help and will not hurt. I have also read that doing power transfer with significant AC motor loads on is tough on the unit. You may want to turn off the air conditioners first if you know you are going to transfer, like when starting the generator, or plugging into a power source.

Most companies do not want the expense of dealing with field failures but design mistakes can be made. Hopefully you can reach someone at the company that can help prevent issues by fully understanding what environments cause the fails. I would also ask if you can purchase just the circuit board if the relays are fine. That could save some money. Your dealings with the company will help you to decide if you want to pursue another company's product. Hope this helps.
later Ed

[Larry and Heidi Lee]

Ed, I spoke to engineer Jim and he offered no explanation for the failures. Aside from the routine diagnostics he mentioned the PCB mounting screws need to be tight because it needs to be properly grounded. Otherwise he could find no fault in the conditions that I was operating the unit.  I questioned him as to other product offerings to see if they had a product that doesnt "self destruct" and his answer was NO. Jim gave me the impression that he receives plenty of calls regarding this model and the only resolution is to replace the entire assemby. They will not sell you the PCB by itself. At one time they allowed you to send in the unit for repair for around $100 but they no longer offer that service. They must be really greedy and dont care about us customers anymore because they quoted me $419.00 plus shipping. I found a new replacement from "Tweety's RV" for a total of $247.46 (includes shipping) yesterday and it arrived today. BTW, I was unable to find anybody that manufactures a combination 50A transfer switch and surge suppresor within the same unit for an RV. If anyone can find one I would be interested to hear about it.

[Edward Buker]

Larry,

Note: I updated this post. The previous web link pointed to the wrong Eaton Cutler Hammer Surge Protector.

I guess they sound like an outfit that is not standing behind their product to the extent that they should. They are not servicing the failed units and want to charge the customer far more than you can buy a new one for from a retail source. In other words I really do not care enough to go out of my way....

Put the new one in knowing that is the customer relationship that you have with this company. When you have a failed unit there is little time to make a real change other than just replacing the current unit. It usually involves more time and planning to reconfigure what you have and find a suitable alternate unit. I checked a couple of temp specs for transfer switches and one was 95F and another was 104F. Inside a box in your bay at 110F outside would probably translate into 120 to 130F unit temp anyway. I would install the new one with a fan feature. You may want to check what the temp spec is for your specific unit.

The price you bought the new unit for seemed fair for what it is. There are companies out there that for $150 to $200 sell just a time delay 50 Amp transfer switch. My coach has the original in it that is 9 years old and it is still good. Less electronics may mean a more robust design here given the temperature your bay reaches. If you go that route plan on buying one that indicates that it has DC relays, the AC relay versions have a loud annoying hum.

You could obtain a separate surge protector for $50 that would be wired in quite simply at the main breaker panel. This for example is an Eaton Cutler Hammer version that is a reputable brand that probably surpasses the capability of what is built into your transfer switch. It clamps a voltage spike to ground in milliseconds and can handle 120,000amps of momentary surge.

http://www.homedepot.com/Electrical-Breakers-Distribution-Load-Centers-Whole-House-Surge-Protectors/h_d1/N-5yc1vZ1xiuZbm05/R-100141856/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Some transfer switches incorporate a low voltage monitor feature. If less than 105V for 7 seconds then open the relay/contactor. You can decide if that feature is desirable for your situation. In general it is a good idea if it does not cause the transfer switch unit to fail.

I like the idea of an electrical breaker panel surge suppressor separated from the transfer switch because it lives in a better controlled temperature and humidity environment. It has an LED that tells you if it is functional, and if it fails you are not out the expense and difficulty of changing the whole transfer switch system. These surge suppressors are sacrificial units that will handle spikes a number of times depending on how severe they are. Expect that your environment may take a "hit" that causes it to fail. In that case I would want to have a separate unit in my inside panel for ease of repair. Hope this helps.

Later Ed

[Larry and Heidi Lee]

Ed, I replaced the old TRC unit with the new unit I purchased from Tweetys. It appears to be a revised model and no longer incorporates the built in phone jack to plug in the Aladdin monitoring function. I am still able to monitor the AC input voltage at the Xantrex display which is okay for me. I will take your advice and look to incorporate some sort of cooling fan too. I think I'll look for an in line surge suppresor to take the first "hit" and possibly save the built in unit fron self destruction? Here are a couple pics of the old and new unit. If you install the new unit as I did I strongly recommend knee pads and maybe even a back support belt. I'm not an electrician so if you notice something I did wrong please let me know.

[Larry and Heidi Lee]

Here's the new unit installed.

[Edward Buker]

Larry,

Good job on the wiring. Looks fine. I know what you mean about working in tough positions. My unit was on the ceiling of the storage bay and just a little too far away to work without stretching. I pulled my unit to isolate the relays from the box and reduce the hum. Mine has the noisy AC relays.

I'm guessing that they redesigned the unit, it looks simpler. Maybe they also improved whatever was failing before.

The cover would be a good place to drill a hole with a hole saw and surface mount a small quiet 120V computer type fan. If there is a knockout near those circuit boards that would allow air to flow past them to be exhausted by the fan that would be good. You could mount a switch on the cover and tie the wiring to the red and white or black and white wires on the output side of the relays. That is the side where the relay outputs are tied together. Use a 1 amp fuse and holder in series with the fan on the black or red wire side. In summer you could leave the fan on and turn it off the rest of the year.

The transfer switch is in the AC line before you get to the Main breaker panel. It would still be a good idea to have a surge protector in the main breaker panel. Both surge protectors will see the spike due to circuit delay and will start to conduct, If one fails you still have the other in place. It is good insurance for less than $50. Good luck with the new unit.

Later Ed

[Bill Sprague]

Ed,

I followed the link to the surge protector at Home Depot and then found the manufacturers website.  I did not find a diagram of connections, but it looked to me you could make an inexpensive and simple and inexpensive portable surge protector for use at the shore power post.  Am I missing something?  

Thanks.

Bill

PS:  My coach did not come with a surge protector and I have not invested in the $400 variety at camping world (yet).  

[Edward Buker]

Bill,

The surge guard that I linked you to is an over voltage unit only. It would take on the most destructive kind of quick event like when a voltage spike comes in the power line from a distant lightning strike or an inductive kick from a motor shutting down and the like. It is the kind of event that can take out a lot of sensitive electronics. The all in one more expensive RV Surge Guard units that you can buy, that are placed inline at the power post, will also disconnect the RV when a long duration over voltage or under voltage condition exists (a brown out). The under voltage condition can damage motorized things like the air conditioner compressor.

The sensitive electronics are "down the line" from the coach breaker panel so there is no real benefit to moving this unit out to the shore post. For the most part the Surge Guard starts to conduct aggressively as the voltage rises but the circuit delay will still mean that the electronics in the coach still see a spike, just clamped at a lower voltage and duration for protection.

I'm not implying that this unit does it all, just that for a modest amount of money and an easy install it is cheap insurance.

When wiring the Surge Guard you will see a ground, neutral lead, and two hot leads to connect in the panel. You will find a ground buss connection, and a neutral buss connection point in the panel for those leads from the surge guard. The hot leads will be connected to several breaker out screws, one on each line of the incoming power feeds. Hope this helps.

later Ed