Dear Dave,
I’m hoping someone can help with this. I put a soft start on the A/C. It works great but now when the compressor runs it causes the TV to pixilate. How do I stop that? —Craig
From Dave:
This came from our RV Electricity Facebook group and I thought it would be a good topic to cover since there are so many replies to it—some good, some not so good.
What brand of soft start was used for RV roof air conditioner
First, some questions I would like to ask. What brand of soft start was purchased, as there are many brands available. If it’s from SoftStartUSA, there are two generations of the original SoftStartRV that are installed directly on the air conditioner and another model, SoftStartUp, that is a pigtail at the pedestal. Also be aware that there are quite a few knock-offs hitting the market that are cheaper—which means cheaper components and possible interference.
Some of the comments in the post on Facebook are from HAM radio operators who are experts at tracking interference that affects their radio signals. Here are two of the comments.
Since the problem began with the installation of the soft start, it is likely generating spurious electrical signals, or “hash.” It can be transmitted over the air as radio frequency energy or over the electrical wires. Two common solutions are shielding the offending device by enclosing it in a metal enclosure (or wire mesh) or placing electrical chokes on the wires. These chokes are usually torrid cores which the wires are wrapped around. Like another fella here, I’m also a ham who has chased down electrical interference. Some ferrite cores on the output of the power wires should cure it.
Ferrite cores
I was not familiar with ferrite cores, so I did a search and found they are actually called several different names such as Ferrite Chocks, Ferrite Ring, and Ferrite Noise Reducers. I realized I have seen these things on power cords of many devices such as computers, radios, and TVs. You can find them on Amazon here.
Verify soft start connections are secure
The ferrite cores might do the trick. However, before ordering those I would start by verifying all the connections of the SoftStartRV (or other brand of soft start) are secure. To install, you would have crimped the appropriate connection to the new device such as a male or female spade connection. A weak crimp would mean a loose connection, which could create the interference. Clean all the terminals with an emery board or tape and spray some CRC electrical cleaner on each end. You can get a can on Amazon here.
Next step to try for RV roof air conditioner and TV issue
If the interference is still there, I would unplug the TV and plug it into a power source that is not in the RV, such as the campground pedestal or at home in a garage. This should isolate the power and give you a clear signal, which would indicate the interference is in the 120-volt line of the RV and not through open air.
I believe you are getting interference through the neutral line, which I have found in several RVs and even at the Surf Ballroom here in Clear Lake, IA. They installed new flat-screen TVs throughout the ballroom and the lounge running RG6 coax from the main switcher all around the perimeter. When they fired up the camera, all TVs and the two projectors had “fuzz” and a scrolling white line.
It took a long time to track down the culprit, but we got lucky by finding one TV that had a perfect picture. That TV was in a spot that the wiring had not been updated to the three-prong (Hot, Ground, Neutral). It had an adapter to plug it into the two-prong outlet. Problem solved. Neutral was feeding back interference that the high tech TVs did not like! You can find the 3-prong to 2-prong adapter on Amazon here.
If you hook the TV power cord directly to an outside outlet and the interference stops, this might be a quick fix.
SoftStartRV product would not cause this problem with RV roof air conditioner
I contacted the SoftStartRV technician. He stated that the product is energized at the startup of the air conditioner but remains idle during operation and would not cause this problem.
You might also enjoy this from Dave
What SoftStartUSA product will work on my travel trailer?
Dear Dave,
I have two questions: What soft start device would you recommend for this camper? How can we make the A/C unit quieter? Thank you. —Ray, 2019 Wolf Pup 16FQ
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Always fun to chase RFI.