Disable PLM progmatically?

[cmidgley]

Hi all,

 

I have found that when our house generator kicks on, our Insteon lights flicker whenever Insteon messages are sent, and the messages never work. We have been unsuccessful in getting the generator to avoid this problem (it's a Briggs and Stratton 10KVA LPG generator with automatic switchover). We can live with the flicker during power outages (unless somebody has an idea to fix it!) ... but we find that the ISY communicates with the PLM continuously (likely due to the error recovery) and causes a non-stop flicker unless we unplug the PLM manually.

 

Our ISY is connected to an ELK M1G and the ELK is aware of when the house is on power generation. I was hoping to be able to disable the PLM when the ELK says we have no power, but I don't see a way to do this from the ISY. Anybody know otherwise?

 

My other ideas here are to either add a relay (controlled by the ELK) between the PLM and it's power (so I can disable the PLM during generator time) - but I'd hate to reduce the reliability of the PLM communications. Would it? The other idea would be to place a relay on the communications line between the ISY and the PLM. Of course the ISY wouldn't be very happy with losing the PLM, but I would think it would work.

 

I could just power off the ISY (again, a relay controlled by the ELK), but it does provide other functions for me that continue to work during the generator operation (such as sending email messages, and controlling our Sonos system) - so I thought I'd ask for advice before designing a solution.

 

Thanks in advance for any creative idea here!

 

- Chris

[Michel Kohanim]

Hi Chris,

 

If you have the ELK module, you can have an ISY program that is based on any ELK input/output.

 

With kind regards,

Michel

[cmidgley]

Hi Michael - Yes, I have many programs doing just that - receiving events from the ELK and doing ISY specific actions. My problem is that what I need to do in that program is to disable all communications with the PLM (because the PLM is causing the lights to go crazy during the generator usage). Is there any way to tell the ISY to suspend all PLM communications, and then resume them later upon another program execution?

 

If not, then I'll likely head down the route of disconnecting the PLM from the ISY via some relays...

 

- Chris

[Michel Kohanim]

Hi Chris,

 

O, I am so very sorry as I didn't understand the question.

 

Unfortunately there's nothing that would suspend communications with the PLM. If you are thinking of putting the PLM on a switch, I must advise against it since there have been many cases where the PLM just dies after reboot (I guess the same is true with generator?).

 

Would you be kind enough define "going crazy" a little more specifically? Is it always the same devices?

 

With kind regards,

Michel

[Brian H]

If the generator is not a pure sine wave output.

It can drive some automation modules crazy or in extreme situations. Damage their power supplies.

[cmidgley]

Thanks all... here is a bit more background. Basically all lights in the house flicker when insteon messages are going around when I'm on generator (all is fine during street power). If I click a switch, all lights flicker for a little bit (and no messages work). The generator is a Briggs and Stratton 40243 autmatic generator with automatic transfer switch. In theory, it is "Computer-Friendly Power: Advanced alternator technology provides safe and stable power for computers and other sensitive electronics". It is an alternator based generator, which implies sine wave output - but clearly there is substantial noise in the generated power and I've found nothing in the service manuals to help me diagnose/correct it.

 

All of my primary electronics are on double-conversion UPS systems - so the ISY, ELK, computers, etc. all stay up during a power outage. Of course the PLM plugs directly into the house power (not through the UPS) in order to communicate with the house.

 

When the house kicks into generator power, the PLM will have lost power for maybe 15 seconds and then will gain power again when the generator flips on. At this point, all lights in the house will flicker continuously (endlessly) until I unplug either the ISY or the PLM.

 

I have a ton of Insteon - I've lost count now. So much so that I've reached my limits on the PLM slots with all my scenes. Something like 90-100 devices.

 

From the sounds of it, unless I can figure out why the generator causes such noise problems (I'm at a loss there, and my electrician is as well - though we've not brought in a generator specialist) - it seems like my best answer is to leave the ISY on the UPS but let the PLM get powered down during the generated power periods. The only debate there is how to shut down the PLM - by a relay between it and the power line, or move the PLM to the sub-panel that has street power ... but that places it two sub-panels (street + transfer switch) away from where the rest of the Insteon circuits are located.

 

Any other creative ideas out there?

 

Thanks!

 

- Chris

[LeeG]

Being computer safe does not mean a pure 60 cycle sine wave. What a power supply needs and what Insteon needs to send Insteon messages over the powerline are two very different things. Insteon sends it messages starting "before" reaching the zero crossing so timing and shape of the 60 cycle sine wave are very important.

 

Most generators do not provide a pure 60 cycle sine wave. If they do they have always advertised that specific point. An alternator does not insure a pure 60 cycle sine wave. If the generator provided that the lights would not flicker and Insteon messages would work. All the other hype about being computer friendly is fine as far as powering electronics is concerned but does not speak to the need of Insteon to sends messages over the powerline.

 

I suggest running Tools | Diagnostics | Event Viewer at LEVEL 3 to see just what the PLM is presenting to the ISY. It may be necessary to Disable certain ISY Programs if they are being triggered by false information presented by the PLM due to the malformed or mal-timed AC sine wave.

[madcodger]

All,

 

Since the PLM is going to lose power (and thus reboot anyway, I think) wouldn't it make sense to just put a simple Elk-controlled relay in the circuit just before the outlet that has the PLM, and have the Elk (which knows power is off) activate the relay when power is off for, say, 2 seconds less than the time it takes the generator to kick in? Then when street power is restored for about 5 minutes it could reactivate the circuit. I don't know the specific relay, but I'm fairly certain Elk or someone offers one.

 

You could even have a variable for ISY programs (part of the IF condition) that suspends the program when street power is out due to the Elk sensing power is out (because PLM will be off).

 

I have similar system and situation to cmidgely, except manual start generator. Most electronics are fine (except two small, cheap UPS's that I'm getting rid of) but Insteon goes crazy. I don't have the flickering lights but no programs work over powerline. So, if PLM is the problem and will reboot anyway when power restored, is it OK to have ISY just try to send signal but find a temporarily "dead" PLM?

[cmidgley]

LeeG - Thanks for the info on generators. Makes sense. I'm stuck with what I have - C'est la vie. I'll try a level-3 diagnostic and see what is causing the messages. If it is my programs, then that would be easy to disable. Thanks for that suggestion!

 

madcodger - I think my flickering lights may be due to a bunch of very old Insteon's - many are six+ years old when flickering was an issue. When I do the next generator test, I'll see what happens on the newer switches as well - if they don't flicker, maybe I need to consider upgrading some of my more important switches just to reduce that. I take it you leave your PLM running, since it doesn't have any side effects for you?

 

Thanks all!

 

- Chris

[ELA]

Hello cmidgley,

 

I have often seen where it is stated that Insteon requires a "pure sine wave".

I have no direct experience on this but I suspect that is not necessarily the best way to explain what the issue is?

 

This is a bit of speculation so if someone has more direct knowledge please correct.

 

I believe what might be more accurate is that Insteon requires a very tightly regulated 60 cycle/sec time base.

The power companies line frequency is very tightly regulated. A generator is likely to allow its frequency to "wander" when compared to the very tight tolerance of the power companies lines.

 

Since Insteon is very dependent upon an accurate zero cross reference it requires a very tightly regulated time ( or frequency base).

 

So in theory a "poor quality" sine wave could still allow an Insteon system to function as long as it maintained a very accurate time base.

 

I say this only as a possible aid in your discussions with your electrician/generator specialist.