Power line Noise: How much is too Much?

[Mvesprini]

I have a power Monterey Instruments Power line signal analyzer I purchased in an attempt to locate and eliminate power line noise in my home. I used to have a fair amount of X-10 switches in my home but I have now swapped those out for an insteon network. I am still experiencing some “communication issues “ and I am being directed to try to locate the source of the noise. Can someone tell me what an acceptable level of noise is? Here is a random reading of the signal analyzer. I do not know if this is a lot of noise or a little noise. I can’t get anyone at Monterey instruments to pick up the phone. Here is what the Readings are.

Noise: .5ms : 09m
.2 to .9ms : 17m

Thanks

MV

 

[electron]

While I can't give you a technical answer, I would check out this recent thread which has some good tips. Personally, the source of these kind of problems has always been a UPS, a surge protector or a bad PC power supply. Good luck!

 

[wuench]

While I can't give you a technical answer, I would check out this recent thread which has some good tips. Personally, the source of these kind of problems has always been a UPS, a surge protector or a bad PC power supply. Good luck!

Realize also that the opposite is also a problem, devices that suck the Insteon signal off the line. A lot of devices have filters built in that will actually remove insteon/x10 signal as they pass by because they are considered noise to those devices. So you not only need to target LV lighting and other devices with transformers as potential sources of noise, but also (as Electron points out) UPS's, surge protectors and to a lesser extent PC's and consumer electronics that will degrade the signal. In either case an Insteon filter should do the trick. I have filters on all UPS's and surge protectors. I haven't needed to filter any other devices at this point. And adding additional insteon devices and access points that regenerate/repeat the signal should also help.

Typically Insteon group communication will be more susceptible to powerline issues since they aren't repeated and verified like device communication. Because group cleanup (which is used for group commands verification) is halted/interrupted when any subsequent Insteon commands are sent. So you may find that if you activate a scene some lights don't respond but if you turn that particular light on individually it will. At least that has been my experience.

 

[MikeB]

Typically Insteon group communication will be more susceptible to powerline issues since they aren't repeated and verified like device communication.

Just to be clear, I believe group commands are not "retried", but they are repeated by other Insteon devices.

 

[Digger]

Can you give examples of the communications problems and why you feel they are noise related? Many times when there are communications issues people blame it on noise but it could be many other things as some have proven.

 

[elcano]

Typically Insteon group communication will be more susceptible to powerline issues since they aren't repeated and verified like device communication.

Just to be clear, I believe group commands are not "retried", but they are repeated by other Insteon devices.

My perception from reading the spec long ago was that they would respond from the first command as a group, and then each one would have to acknowledge in a specific timeframe. If any device does not ack, then the command is resent (to that one?). But, well..I'm not sure about this. My overall impression about the protocol was that it didn't have many open issues, as the designers looked into solving problems from earlier technologies.

 

[MikeB]

The sending device broadcasts an initial group command. Any devices that hear that command and are members of that group react accordingly (turn on, turn off, whatever). The sending device then sends out direct commands (cleanups) to each member of that same group to confirm they received the initial group broadcast. If any of the members do not respond, the sender re-sends the direct command up to 5 times.

 

[Mvesprini]

[/quote]Typically Insteon group communication will be more susceptible to powerline issues since they aren't repeated and verified like device communication. Because group cleanup (which is used for group commands verification) is halted/interrupted when any subsequent Insteon commands are sent. So you may find that if you activate a scene some lights don't respond but if you turn that particular light on individually it will. At least that has been my experience.
[/quote]

I think you nailed it. That is where I am having the most trouble. Scenes that control multiple devices, Like an all off scene that controls 20 devices. Is there a fix?

MV

 

[Mvesprini]

Can you give examples of the communications problems and why you feel they are noise related? Many times when there are communications issues people blame it on noise but it could be many other things as some have proven.

The trouble I am having is controling scenes I have created for the ISY. In particular, when I want to trigger a scene with another device, such as a double tap on a switch linc dimmer. For instance, in my master bathroom, I have 7 seperate lights controlled by 5 switch linc dimmers, a switch linc relay and a 6 button KPL. When I leave the room, I want to double tap the SLD at the door to trigger a program to turn ALL of those 7 lights off. some times it works 100 %, some times all but one or two stay on, some times they all go off except one ramps down over 5 seconds. ( they are all set to ramp down at .5 seconds.) I have checked connections and in some instances replaced switches in this scene. I also have a horrendous buzz in a whole house audio system on the AM band that NO ONE can troubleshoot. I also have rolling bands on some of the TV's in my house. On the big screen Hi-Def TV's I have some heavy duty power condioners that have cleaned that up. I am in the process of going throught each circuit in my home trying to locate the source of the noise. It is a lenghty task though, I have a main panel with 40 breakers, a secondary panel with 38 breakers and two sub panels, one with 32 and another with 9. That is 119 breakers I have to check out. If only I did no have a job and a family and a life, I could probably get to the bottom of this in a month or so!!

A few of the folk at UDI have suggested that I have communication problem in my system. Which brings me back to my initial question. How much Noise is too much noise. I spent $300 on a power line signal analyzer which tells me I have noise, but no one can tell me how much is too much?

Suggestions?

Thanks

 

[Digger]

Every home electrical system has some noise. Just because there is noise does not mean that it is effecting your Insteon setup. I am not saying you dont have communication problems but I dont see any proof (yet) that it is noise causing the problem (cant say it is not either with any certainty but you may be chasing your tail here is what I am trying to point out).

If you live 100 miles from an FM radio station and are trying to pick it up on a small hand held radio you will get poor reception depending on the power of the transmission, the height of the transmitters antenna, the height of the receivers antenna etc. You will also hear noise in the reception because the signal is to weak to overcome it.

Insteon puts out about a 5 Vpp signal which is very weak just like X-10. Many INsteon devices will repeat a message (an improvement over X-10) but that does not mean your message will always get through. Can noise at the correct frequency block or corrupt this weak signal? Yes. But you could have no noise and the signal not make it as well if the distance is to far for the signal level INsteon devices put out. Smarthome will tell you to "buy more" and admittedly there is some truth to that. The more repeaters you have the better the odds of the signal making it from point A to B but there is no guarantee it will fix the problem.

UPB uses a much stronger signal (over 30 Vpp if I remember correctly) but its devices do NOT repeat the message. You do not need a minimum amount of devices to go from point A to B since it is designed to get there on its own without repeaters in between. In some respects it is better until your message doesn't get there because you cant just "buy more" to try and overcome the problem. You will probably read a lot less posts about UPB and noise then Insteon and noise when in theory noise could affected both almost equally. Why? Because with Insteon it may not always be noise but a weak signal but people blame noise rather than the products shortcomings (one of which is a weak signal compared to other types of PLC devices).

Some people will say it is "signal suckers". Well a 5 Vpp signal can easily be made useless compared to a 30 V pp signal by a UPS etc.

Try turning off breakers or unplugging suspect devices if you feel you have noise or signal suckers. It can take hours or days to narrow down or you may not come to a conclusive answer.

Good Luck!

PS if you like troubleshooting all of the time stick with the INsteon it will keep you happy.

 

[IndyMike]

The trouble I am having is controling scenes I have created for the ISY. In particular, when I want to trigger a scene with another device, such as a double tap on a switch linc dimmer. For instance, in my master bathroom, I have 7 seperate lights controlled by 5 switch linc dimmers, a switch linc relay and a 6 button KPL. When I leave the room, I want to double tap the SLD at the door to trigger a program to turn ALL of those 7 lights off. some times it works 100 %, some times all but one or two stay on, some times they all go off except one ramps down over 5 seconds. ( they are all set to ramp down at .5 seconds.) I have checked connections and in some instances replaced switches in this scene. I also have a horrendous buzz in a whole house audio system on the AM band that NO ONE can troubleshoot. I also have rolling bands on some of the TV's in my house. On the big screen Hi-Def TV's I have some heavy duty power condioners that have cleaned that up. I am in the process of going throught each circuit in my home trying to locate the source of the noise. It is a lenghty task though, I have a main panel with 40 breakers, a secondary panel with 38 breakers and two sub panels, one with 32 and another with 9. That is 119 breakers I have to check out. If only I did no have a job and a family and a life, I could probably get to the bottom of this in a month or so!!

A few of the folk at UDI have suggested that I have communication problem in my system. Which brings me back to my initial question. How much Noise is too much noise. I spent $300 on a power line signal analyzer which tells me I have noise, but no one can tell me how much is too much?

Suggestions?

Thanks

To answer your original question - the 9mv and 17mv noise registered by the Monterey should not be sufficient to disrupt a "properly functioning" Insteon system. The repeating nature of the Insteon devices should keep the signal high. How high depends on the length of the runs between repeaters and the type of devices installed on the line. Since the measured noise appears low and you are still having communication and TV noise problems, the noise is either intermittent or in a frequency range the monterey wasn't designed to pick up.

Your Monterey should also detect the Insteon signal. It will most likely tag an Insteon transmission with "BSC" (bad start code) or "BCY" (bad cycle count) but it should report the signal level. Try a test on the same circuit as your PLM to baseline the level there. Activate a switch via the PLM and note the level of the first few transmissions (note: the first few transmissions will be from the PLM the trailers will be from repeating devices and may be lower level). Then move your Monterey to other circuits and repeat the procedure. For reference, my house is half the size of yours, my ELK ESM1 registers 5V (pegged) throughout the house.

If for some reason your Monterey doesn't detect Insteon via the BSC and BCY codes, you can also use the noise measurement mode during an Insteon transmission. This is likely to be less accurate since the Monterey will be averaging the Insteon signal level over a period of time. It should still be significantly higher than your background noise.

The fact that you have rolling bands on multiple TV's that can be removed with powerline filtering is a bit ominous. TV's normally have pretty good filters - I've never used a separate filter to remove noise from a TV. Since you have this on multiple sets it may be easier to troubleshoot the set noise in the hope that it will also cure your Insteon problems.

Try removing the filters from one of your TV's (yep - let's make the bands reappear) and then start pulling breakers. I think you already know the routine from here on out...

IM

 

[briankelly63]

I appreciate your frustration.....try to isolate the problem by shutting off subpanels first. A scope might be of some help with a problem like this... This is the issue with some of these powerline carrier or rf type devices, there are just a lot of points of failure especially since the pattern of how the signal is repeated may change depending on powerline noise or even obstacles that move in or out of a given repeater path.
I'm concerned about some of the power quality issues you mention... there should be nothing happening on your powerline that should require all this filtering.

Sorry no quick fix....

Brian