Bizarre.

Sorry this is a bit offbeat, but I just have to know what is going on here. I have a Sil-Aire compressor and every time it kicks on my Zune mp3 player turns off.

What makes this particularly strange is that the player isn't plugged into anything at all when this happens, and it is about 4 feet from the compressor.

Do these compressors emit some sort of radio current or some sort of signal that would do this?

I'm no electrical engineer, but I know that anything making a spark is making a radio frequency. This includes all electric motors. It seems odd that it is affecting your player, but there may be a way to supress the RF interference using a capacitor or two. I know how to do it on alternators and ignition systems but I'm not sure exactly about a motor. You should be able to find the info somewhere online. Meanwhile I would move it further away or place some metal sheet between the two, it might possibly damage the player.

Hi Michael

Could it be the vibration of when it kicks in. It is a bit of a jolt. Try moving the mp3 away from the compressor a bit more.

Either that or it's some sort of strange radio frequency thing So if the fillings in your teeth start picking up the local radio station you know you are in big trouble

Cheers
Andrew

Michael:
Any motor or electrical device will give off a "Electro Magnetic Pulse" This is epically true on startup, of an item. If you have a Radio Shack Store near you, see if they have any ferrite dampers/chokes, they will generally clip around your power cord, put one as near as possible to the compressor, and another near the plug. They do not require you to cut into the wire. They will help to dampen the effect of an EMP. Also another trick is to build a fence of aluminum foil between the compressor and your player, keep that as close to the player as possible. Either one should fix your problem, and they should be less than $10 for the pair. The last time I bought some They were abt $ 2.50 ea.

Michael:
Another item you might want to do is to check All electrical joints in the compressor, as a loose connection will create a major EMP spike.

From my personal experience, the most common issue associated with transmitted random RF (radio frequency) and or EMP (electro-magnetic pulse) generation associated with electrical devices is missing or incorrect equipment safety ground bonding.

A standard 120 volt AC outlet has three connection points: "hot" - line/feed/supply that is always energized; "common" - return to source current conductor; "ground" - equipment safety conductor that should only carry current when the device is in a fault mode.

The primary function of the "ground" bonding conductor on an electrical device is designed to protect the operator when a fault condition occurs such as when a normal current carrying conductor comes in contact with the device case. The ground is supposed to then carry the current to earth ground causing a direct short circuit allowing the current interrupting device (fuse/breaker) to open the circuit and cease current flow and voltage potential. The secondary function of the ground bonding conductor is to help control transmitted random RF/EMP generation by creating a ground shield around the electrical components.

If the equipment ground is missing or broken at any point, including case bonding within the device itself, it cannot provide a current path to earth ground allowing not only transmitted random RF/EMP generation to pass but also creating an unsafe operational condition of the equipment affording the possibility of electocution to anyone coming in contact with the device should a fault condition be present. I should note that ground shielding is less effective on EMP than it is on RF.

Some exceptions are those devices contained within plastic or other non electrically conductive housings - IE: those devices listed as "single/double insulated". This type of construction works fine for personal safety protection but the non-conductive housings will pass transmitted RF/EMP quite easily. Switches making and breaking connection cause limited arcing however any time an arc is created, it released a certain portion of energy to the air in the form of an RF/EMP. Along with the pulse released to the air, another pulse is released through the electrical wiring which may or may not be transmitted through the air via the conductors.

Ferrite beads/blocks will help quell the RF/EMP (noise) transmitted via the wiring but they will not have any effect on voltage spikes within the conductors. Voltage spikes can be generated by numerous sources but those associated with electric motors generally come from the start/run capacitors and or the motor windings. Generally the voltage spikes are not sufficient to cause damage or operational problems with other electical devices unless there is a fault within the device that is allowing the spike(s) to reach unacceptable levels - IE: winding or capacitor issues. However, something in the form of a sensitive electronic device, like your MP3 player, will have a much lower tolerance when it comes to RF/EMP issues - BUT - when you find a something like the condition you're experiencing, it is often an indication that some other more serious problem exists suggesting that a full system inspection should be done.

With age and use, electrical devices experience both mechanical and electrical wear. This includes all electrical devices and connections from the utility supply point outside the structure, distribution and connection points within the structure and right on down to the end-use device. Most people tend to ignore perventative maintenance schedules on their electrical systems and don't even give it a thought until sometime major happens ... like a fire or when they get electrocuted. In residential applications, a full electrical PM should be done every five years or less; residential work/hobby spaces should be done every two or three years depending on the amount of use they see; commercial applications should be done no less than once a year.

I'm not being rude but putting a band-aid on the MP3 player may be doing nothing more than painting a ticking bomb pink so it looks less dangerous but the color of the paint isn't going to help when it goes boom. Hopefully your problem is nothing more than a sensitive MP3 player but it never hurts to look for other problems before they result in more than just stopping the music.

Line filters for AC and DC systems are completely different and cannot be interchanged! Line filters are available for AC systems however they must be correctly engineered to the application for which they are being used. There is a lot of junk out there on the market, little deals for under $100 that plug into an existing outlet and some hard wired units that run upwards of $1000 and either type can be completely useless to you if they are not made to address the specific conditions within your electrical system. Don't get suckered by a fast talking salesman, deal with a reliable electrical contractor who knows noise filtering - you can NOT check for line noise with a standard voltmeter, you must have an oscilloscope or similar device capable of measuring/detecting RF and or EMP. Some contractors will not knowingly mislead you, I have come across several who were well meaning but who did not have the proper knowledge about RF/EMP control hardware, most were simply suckered themselves by company salesmen who supplied them with generic devices. I'm also not saying that just because a device is considered "generic" that it doesn't work, there are plenty of "generic" devices out there that will work for certain applications and won't require you to obtain a home equity loan to install, yes there are units selling under $100 that do in fact work but you need to know what you're buying or it'll end up being wasted money.

Wow, Fl, thank you for all that info. It is early here but I think I am wrapping my head around most of what you are saying.

At this bench I have my gravermach, a halogen lamp, and small speaker system for the mp3 and the compressor. The system is commonly connected through a 12-outlet industrial grade power strip/surge protector which I picked up for about 50 bucks. I figured it was worth getting a better one than average for these brand new tools, however from what I am gleaning from your advice, it sounds like it may be doing nothing to supress feedback from the compressor.

I did forget to mention that although the player is not plugged in to anything when this happens, it usually sits on top of my bench, and the power strip unit is mounted under the bench near the top to keep wires off the floor, so in fact the space between the two is only about 16". If there is any line noise, or EMP, it could just as likely be coming from that strip, right?

Today when I am at the shop I will try moving the player away and around the room while I run the compressor and see if that changes things. Btw, initially I had the player plugged in to the speakers through the audio output on the player, and the speakers share a common circuit with the compressor through the power strip. When this first happened I thought it was just some static through the actual wiring. What really confused me to the point of starting this thread is why it continued to do it all through the afternoon even after the player was disconnected from everything.

I will try a few things and let you know what I come up with. Thanks to all for the advice,

Michael

Sounds like FL-Flinter has covered things pretty thoroughly but I figured it was still worth chiming in that I get a little bit of interference on my FM radio from my GraverMach SC. I know it's from the Graver and not the compressor because I can turn it off and on with the GraverMach's power switch.

Probably just need to move the external antenna I have to use in my little semi-underground corner (garage set into the hillside).

Geeze, I wrote my reply around 4:30am, about a 45 minutes after I got up, got called away and didn't get it posted till a little later though.

Yes, you can be getting noise floating on the electrical wiring that doesn't necessary have to be in direct contact with other equipment in order to cause problems. I'd be interested in knowing the results of your test by moving the MP3 player around to different locations.