GFI ?????????

[Kays Supply]

Ok ,since there are several electrical questions on this site, her is one for you. My son is a County Deputy. He just got a new radio. It is battery powered. When he keys the mic in his bathroom, the GFI pops. He did it several times to make sure that is what caused it. This can NOT be a good thing. Can someone explain this? I am worried about him using it up near his head. I have heard of all kinds of problems caused by radio waves, etc.

 

[kenstrac]

I would try it next to another GFI and see if it trips if it dosn't change the GFI out.
If it does then have him swap radios with another and see what happens,process of elimanation.

 

[Soundguy]

I have a guess, and a sugestion.

a gfci is a compairing device.. it compairs the hot and common line.. My bet is your rf output is making the gfci think there is a ground fault.

hit a store and buy one of those emi/rfi/spike blocks.. they are usually only about 4 bucks.. or.. you may already have an outlet strip that has spike PLUS EMI/rfi filtering. if it does.. plug it in.. then see if the gfci still trips.

post back.. I'm curious.

soundguy

 

[MT. Sparky]

How can you explain something that you cannot see, just kidding. I probaly would just go get a new GFCI outlet and replace it, they are not that expensive.

 

[Treemonkey1000]

Could be a defective GFI or a low cost one. First thing I would try is to pull it out and make sure all of the terminals are tight. If they stuffed the wires into holes in the body of the GFI that have a blade that bites into the wire to make contact I would either pull those out and use the screw terminals or push them in to seat them better. His radio signal is causing the wires to act like a little antenna which is tripping the GFI.
PS: Tell him to finish his business in the bathroom and quit yacking on the radio...

 

[JB4310]

I think OP is more worried about the radio waves causing health problems, not the function of the GFI. He already confirmed the Radio transmit is causing the trip. It may or may not mean anything health wise, but changing the gfi for one that doesn't trip isn't gonna lessen the risk (if there even is one).

If that's a county issued radio then I'm sure it's got a powerful transmitter. more than the .5 watt our cell phones put out that every one's so worried about. What does it say on the label of some consumer electronic devises? "this device must accept interference but cannot produce /put out interference" Something like that, wonder if that same rule applies to Govt Communications equipment.

GFI's are sensitive, I have some that pop just from static build up when you touch them.

.

 

[Treemonkey1000]

Good point on the concerns. A lot of radios in that service band are around 800 Mhz. There is still a fair amount of unknowns on Magnetic waves and health issues. The risk is still pretty low I think considering how much RF is in the air anymore and the amount of cancer related to that. Some of those radios have a low and high power setting if he can use that. Having been a Ham radio operator for 20 years I have been a around a lot of RF. My work I deal with a lot higher frequencies and higher power daily. So far no health issues with myself or any of my co-workers.

 

[J_J]

Just tell him not to get around anyone with a pacemaker, just might shut it down, or switch it to high mode.

 

[aczlan]

If that's a county issued radio then I'm sure it's got a powerful transmitter. more than the .5 watt our cell phones put out that every one's so worried about. What does it say on the label of some consumer electronic devises? "this device must accept interference but cannot produce /put out interference" Something like that, wonder if that same rule applies to Govt Communications equipment.

The difference is that the devices with the label you mention (remotes, tvs, baby monitors, etc) are "secondary users" of the band that they are using and as secondary users, they are not allowed to cause interference to the primary users. Cell phones, radios (Police, Amateur (Ham) or Business), etc are licensed as the primary users of their respective bands and as such are allowed use more power and can cause interference to the secondary users without any legal repercussions.
An example of this is what happens (happened?) to garage door openers when a navy ship comes into port with the radar on, the frequencies conflict and people with RF garage door openers cannot remotely open their doors as the radar is on the same band and is MUCH more powerful, drowning out as it were the signal from the remote to the opener.

Aaron Z

 

[ultrarunner]

Just tell him not to get around anyone with a pacemaker, just might shut it down, or switch it to high mode.

Not as far fetched as it may sound... We have strict limitations in the I.C.U. unit and Operating Rooms at the Hospital where I work.

Also, Hospital Grade GFCI have better shielding, plug retention and less prone to nuisance tripping... they also cost a lot more... at least the ones I buy from Hubbell do.

 

[Cat_Driver]

I'm in the entertainment business and this is pretty common. It has to do with the equipment powering the mic.

Audio Noise and AC Systems

This will explain it beter than I ever could, but be assured I had the same problem with a new $3,000 Electrical theatrical distro box five minuted before a show and was beyoun upset.

It's how the amp is throwing the signal back. The GFI are so sensitive that when they pick up the slightest and I do mean slightest anomonly they trip, well, because they are designed to.

 

[Kays Supply]

Thanks all, I am still concerned, but will check the grounding. He lives in a trailer, so grounding could be the issue.

Catdriver, my brain is smokin after trying to absorb that article. It does give me a place to start though.

 

[The Haymaker]

There is nothing wrong with the house wiring. The RFI from the radio is causing transient currents to flow along the wires (and EVERY conductive material in the house), which trips the GFI. If I park the pickup close to the house and transmit on HF (much lower freq than what your son is using) at 100w, I actually trip BREAKERS in the home!

Other than dropping output power or finding a less sensitive area of the trailer, there's not much you can do about it.

Shielding the wires, which wouldn't be feasible in a house, would help.

You could try swapping out the gfi unit, simply because higher quality units may not be as susceptible to rfi, or not as bothered by the frequency being used.

As for the health issue caused by RF, I'd not worry about the max 7 watts that HT could be putting out. It is nothing compared to the rf out there from everything in todays modern aged. Just think what the rf from the 1 million watt broadcast station down the street is doing!

E

 

[J_J]

It would seem from a layman's standpoint, that any transmission, or leakage through out the circuit greater than 5 mA between the neutral and hot will cause the GFI to trip. This is the UL standard. This could be from a real problem or an induced problem as in radio transmission.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gfi.html

Talking about RF transmission, while in the Navy many years ago, a friend of mine said, see that guy carrying a box of florescent lights, he said watch this, and he triggered off the radar on the P2V, and caused the florescent bulbs to light. He said RF energy. We also had a guy claiming the radar made him sterile. He was serious, but could never prove it. Another situation, just about out of 10 times a P3V passes over my house, the wireless doorbell rings. Every time I hear the doorbell, I listen for the P3V and I can recognize the sound of the engines. Apparently there is some transmission from the P3 that is on the same frequency or is a side band of the transmission. So if I hear the doorbell and the P3, I don't bother going to the door. I have heard this thousands of times before, because I have lived here for about 35 years, and I flew in the P3's for about 15 years.

 

[The Haymaker]

JJ, that's a pretty cool side effect from either the direct emissions or it's harmonics.

If one is worried about side effects of RF, it's a good thing they don't live near NAVCOMTELSTA Cutler! I deliver goods there and the place is amazing, everything built on a massive scale.

NCTAMS LANT DET, Cutler, Maine

cutler naval base - Dogpile Web Search

 

[JB4310]

The difference is that the devices with the label you mention (remotes, tvs, baby monitors, etc) are "secondary users" of the band that they are using and as secondary users, they are not allowed to cause interference to the primary users. Cell phones, radios (Police, Amateur (Ham) or Business), etc are licensed as the primary users of their respective bands and as such are allowed use more power and can cause interference to the secondary users without any legal repercussions.
An example of this is what happens (happened?) to garage door openers when a navy ship comes into port with the radar on, the frequencies conflict and people with RF garage door openers cannot remotely open their doors as the radar is on the same band and is MUCH more powerful, drowning out as it were the signal from the remote to the opener.

Aaron Z

Yup, that's what I was trying to get at, "Priority users have the right of way" if you will.

You don't want a soccer mom with her family radio interfering with a military exercise.
Not sure it relates to the gfi issue but it might.

 

[SPIKER]

You might want to tell him to not be using his radio near/in any hospitals as they do shut off machines. Few if any Cops seem to think they can do what they want regardless of others problems. The trailer has the extra metal shielding of the metal exterior & can cause signal degrade and as such the radios will power up into high output which can cause additional power output and trip the sensitive equipment anywhere in the 50 yard radius..

The local cops would key their radios and trip car alarms all around just for fun and to see if anyone was home to shut the car alarms off and if they were away they were citing the people to earn extra income!! I know all about that!!! You have 45 seconds to shut off the alarm here or else find a nice 45 buck for 1st offense ticket on the car. Car alarms have settings as to how long they chirp, the 5 sec chirp and so on on most of them, mine was set for 15 sec. the cop would keep clicking the mic and bang new ticket...

mark

 

[rich_ncal]

"As for the health issue caused by RF, I'd not worry about the max 7 watts that HT could be putting out. It is nothing compared to the rf out there from everything in todays modern aged. Just think what the rf from the 1 million watt broadcast station down the street is doing!"

The power falls off with the inverse sqaure of the distance. So that 7 watt HT held 6 inches from a person's head is exposing the person to electric fields hundreds of times larger than the 1million watt broadcast station one mile away.

Best pactice for low exposure to RF is when able to to use a whip antenna mounted out side a car and to use the HT only when needed when out side of the car.

 

[Soundguy]

Yep.. I think that's exactly the issue.. even with no current flowing.. IE. nothing plugged in.. if the gfci see's an imballance betweent he lines it trips.. and the rf induced flow could be enough.

I bet that xmitter can make a neon or flourescent lamp pulse or glow...

soundguy

It would seem from a layman's standpoint, that any transmission, or leakage through out the circuit greater than 5 mA between the neutral and hot will cause the GFI to trip. This is the UL standard. This could be from a real problem or an induced problem as in radio transmission.

Ground Fault Interrupter

Talking about RF transmission, while in the Navy many years ago, a friend of mine said, see that guy carrying a box of florescent lights, he said watch this, and he triggered off the radar on the P2V, and caused the florescent bulbs to light. He said RF energy. We also had a guy claiming the radar made him sterile. He was serious, but could never prove it. Another situation, just about out of 10 times a P3V passes over my house, the wireless doorbell rings. Every time I hear the doorbell, I listen for the P3V and I can recognize the sound of the engines. Apparently there is some transmission from the P3 that is on the same frequency or is a side band of the transmission. So if I hear the doorbell and the P3, I don't bother going to the door. I have heard this thousands of times before, because I have lived here for about 35 years, and I flew in the P3's for about 15 years.

 

[The Haymaker]

"As for the health issue caused by RF, I'd not worry about the max 7 watts that HT could be putting out. It is nothing compared to the rf out there from everything in todays modern aged. Just think what the rf from the 1 million watt broadcast station down the street is doing!"

The power falls off with the inverse sqaure of the distance. So that 7 watt HT held 6 inches from a person's head is exposing the person to electric fields hundreds of times larger than the 1million watt broadcast station one mile away.

Best pactice for low exposure to RF is when able to to use a whip antenna mounted out side a car and to use the HT only when needed when out side of the car.

Yes, I agree, I was only making a point. There is RF everywhere.

Yep, external ant. is the answer, but that kinda limits the usefulness of a handheld in the first place.

It's just rf. There's nothing wrong with the radio. There's no voodoo, it's merely the side effect of a sloppy engineering job on the part of the gfi manufacturer.

Here's a little on GFI theory.