Installing a Generac Generator

[ergodic]

I just completed the install of a 20KW Generac generator at the house.

 

This post is just to share the experience as it relates to the ISY and Insteon. I'd also like to thank the several forum users who corresponded with me in advance of my getting the unit as it helped me know what to expect.

 

The Generac unit and whole-house transfer switch are straightforward installs and it only took about a day including the propane piping and so forth. There was debris lodged in the 1/4" propane feed line that took another couple of hours to figure out - it was causing the unit to shut down after starting. But other than that no real install problems. (But I've decided to start a "tray cable is too damn high" party. Residential tray cable is now running about $1 per INCH.)

 

There is one odd part of the design of this unit I will warn you about: that little 6-wire 18ga Generac control line is carrying full 240V line power to the generator unit for it to sense utility power. There is no isolation or step-down, just fuses on each of those 3 lines. No kidding. I discovered this the Bad Way when tying it up and I accidentally nicked through the thin insulation on the bell wire, touched one to the metal flex and spent most a day looking for a very-hard-to-find 5A fast-blow mini fuse. (thank you Fuseco in Laguna Hills, CA.)

 

My main concern was being notified when the generator goes on or off if we're not here via SMS. To do that I wired up an Smarthome Inlinelinc with sense. The Inlinelinc is powered from house power (utility or generator) and its sense lead is tied to one leg of the Generac output, all just simply stuck inside the roomy transfer switch box itself. The Inlinelinc load is of course not connected to anything, we just want the sense.

 

The picture below shows it wired-in at the bottom right-side cabinet, just below the neutral bonding plate in the transfer switch. It is secured with a little velcro on the back and a tie wrap, there are no useable mounting holes. The power for the Inlinelinc is run through the conduit to the main breaker box on the left and tapped from the same breaker that connects up my access points below the breaker panel. I did observe that the Inlinelinc is more fussy than most devices about signal so getting it close to an AP is probably worthwhile.

 

 

 

This setup also means the Inlinelinc loses power for a few seconds during the switchover. This is harmless and causes no issues.

 

I also did scope the Generac output on advice from several people. The 20KW Guardian is the largest of Generac's true-sine units and I saw absolutely nothing to concern me. No spikes during the transitions and no h/f noise. There is a little visible distortion in the A/C waveform which matches exactly with what I see when I'm on utility power -- just the way the house loads. Frequency bobbles around a bit from 59.4Hz to 60.5Hz. No big deal there either. I have no worries about the Generac causing any problems with Insteon. Everything communicates fine.

 

What does cause an issue is the Generac sense, which bounces around during its cut-in and cool-down phases while the voltage is stabilizing. This causes the Inlinelinc to "jitter" from off to on to off quickly and randomly in those intervals. If you're looking for an SMS text message from this, you'll definitely get a few!

 

I initially tried to solve this with hardware: I breadboarded a little RC-diode circuit to try an smooth all this out, but never could come up with anything reliable. I still don't know if it is because the Inlinelinc sense expects A/C, or there's just too much variability, or I was just tired. I do know for sure my wife was very tired of my testing. Anyway, this is the digital age, so we ought to solve it with software anyway.

 

To fix this we just need a few ISY programs to sense the transitions over a long period, ignoring short on/off sense line changes of a few seconds. I eventually settled on 7 second or less fluctuations and a wait of 90 seconds to determine that the unit is really on or off. There are arguments for other numbers, but these worked fine the first time.

 

These first 5 programs are a little 3-state machine that does the on-off smoothing. They use two state variables: $Generac.On.State to track the state of the state machine itself, and $GeneracCurrentStatus as an "output."

 

//GENERAC.B0 (waiting to come online)
If        $Generac.On.State is 0 
Then        $GeneracCurrentStatus  = 0

//GENERAC.B1 (Generac sense is on. Ignore short off transitions)
If        $Generac.On.State is 1
Then        $GeneracCurrentStatus  = 1

//GENERAC.B1 If
//Off transition on Generac. If not too long then ignore it, o/w reset to B0 after wait
       $Generac.On.State is 2 
Then
       Wait  7 seconds
       $Generac.On.State  = 0

//GENERAC.C1: Jump to state B1 when sense goes high
If        Status  'Generac Sense' is On
   And (
            $Generac.On.State is 0
         Or $Generac.On.State is 2
       ) 
Then        $Generac.On.State  = 1

//GENERAC.C2: Jump to state B2 when sense goes off
If        Status  'Generac Sense' is Off
   And $Generac.On.State is 1 
Then
   $Generac.On.State  = 2

 

These next two programs implement the on and off waiting period. They use $GeneracCurrentStatus as an input and, after 90 seconds of an unchanged $GeneracCurrentStatus, they set the final state variable we're actually interested in: $GeneracIsOn.

 

//GENERAC.C2: Jump to state B2 when sense goes off
If        Status  'Generac Sense' is Off
   And $Generac.On.State is 1 
Then
       $Generac.On.State  = 2

//GeneracGoingLive
If        $GeneracCurrentStatus is 1
Then
       Wait  90 seconds
       $GeneracIsOn  = 1 

//GeneracGoingOff
If        $GeneracCurrentStatus is 0
Then
       Wait  90 seconds
       $GeneracIsOn  = 0

 

The last program uses $GeneracIsOn and is the one that actually drives the notifications out.

 

//Generac.SendMessage
If        $GeneracIsOn is 1
Then
   Send Notification to 'steve.sms' content 'Generac.On'
Else
   Send Notification to 'steve.sms' content 'Generac.Off'

 

One more thing I'd like to implement is some way to remotely turn off the generator via the ISY regardless of whether utility power is on or off. It is easy to fire it up by simply opening one of the utility sense leads with a relay, simulating a power failure. But as yet I've found no control point inside the transfer switch where a generator-off can be done easily and it may not be possible. But at $4/gallon for propane and a 250 gal tank, I'd sure like to.

[Xathros]

Nice looking installation there. Congrats!

 

As for the remote shutdown my bet would be the low oil switch circuit for an easy relay operated remote generator shutdown. Of course, this means another pair run out to the generator. Otherwise maybe look for the V+ for the CDI and put some relay contacts in series with that line.

 

 

-Xathros

[ergodic]

Thanks. That's a good idea. I wasn't even thinking outside the transfer switch.

 

There's actually an extra (green) wire in that control cable, if the circuit is on a common ground I can use it, though it wouldn't be much to run another little cable. Or I could just stuff the iolinc inside the generator itself - signal gets there just fine. I'll let you know once I try it. I want to talk to the service contract people to be sure they're OK with that mod.

[Xathros]

Thanks. That's a good idea. I wasn't even thinking outside the transfer switch.

 

There's actually an extra (green) wire in that control cable, if the circuit is on a common ground I can use it, though it wouldn't be much to run another little cable. Or I could just stuff the iolinc inside the generator itself - signal gets there just fine. I'll let you know once I try it. I want to talk to the service contract people to be sure they're OK with that mod.

 

 

I'm not sure that inside the generator would be a friendly location for an IOLinc. There won't be line power there or a connection back to the rest of the insteon network unless the generator is running and the transfer switch has flipped to the generator side. This means no comms with that IOLinc under normal conditions. Also, the power at startup and shutdown of the generator is not going to be nice. I'm not sure how well the IOLinc will stand up to that. I think the house side of the transfer switch is the best place for the IOLinc to live.

 

Thinking a bit more about the remote shutdown aspect, Cutting the power to the CDI is probably not a good idea as the generator will still likely continue trying to start thereby running down the starter battery. The low oil switch *should* prevent it from trying tho there may still be an active drain on the starter battery. Some testing beforehand should be done. I would think there is a method for taking the generator offline that you may be able to tap into and with any luck, that may be at the transfer switch.

 

-Xathros

[ergodic]

I've already tested the oil sense idea this morning and I think it should do the job, though I forgot to check how easily it comes back once it's faulted that way.

 

I've installed a low profile outlet inside the transfer switch to plug in the iolinc there, but I need to now build a little modular spade lug insert pigtail I can put inline at the oil switch to insert this run easily and without cutting into the Generac's wires or connectors. Service is fine with it as long as it's easy to pull out.

[Xathros]

Excellent. Please let us know how it works out for you. I have some long term plans for doing something similar at my place.

 

-Xathros

[ergodic]

I won't be doing the oil shutoff kill switch after all. It aborts the cool-down cycle and everything related to a 'normal' shutdown. Not a really good plan I think.

 

So the only way I can see from the prints I have would be to splice directly into that rocker switch on the generator and simply make it think it's been turned off (center position). I haven't looked at the physical wiring under that panel to see how nasty that would be to do cleanly. I also have to talk to service to make sure they'd be OK with it and not affect the warranty.

[Xathros]

I won't be doing the oil shutoff kill switch after all. It aborts the cool-down cycle and everything related to a 'normal' shutdown. Not a really good plan I think.

 

So the only way I can see from the prints I have would be to splice directly into that rocker switch on the generator and simply make it think it's been turned off (center position). I haven't looked at the physical wiring under that panel to see how nasty that would be to do cleanly. I also have to talk to service to make sure they'd be OK with it and not affect the warranty.

 

I'm sorry to hear that. I still wonder if there is a way to trick the transfer switch into thinking that utility power has been restored or to tap into the control circuitry at that point to tell the generator to do a normal shutdown.

 

Please do let us know if you find a workable solution.

 

-Xathros

[jzsjr]

Ergodic,

I know this is an old thread but was hoping you were still monitoring this forum. Most of the new generators I believe are coming with data connections and the like but I have a generac around the age of yours that could only be outfitted with a wireless monitoring device that did not work for very long. I'm guessing the board got fried or was not set up to work in the elements. I, too, would like to simply know when the generator is running via an email or text. I'm trying to hash out your connections a bit. First off I don't think Smarthome makes the inline linc any more. They do have some micro switches that have a sensing wire but I also have an i/o linc that has sensing capability but has to be plugged into an outlet. I was wondering if you were just sensing that the generator is running or are you separating out whether it is exercising or running with load? If it is just the generator running in general where is the output you attached the sensing wire to and did you also connect the ground? I've been playing around with using a current switch that wraps around the a load wire but not sure if this is what I want to do. I already know when the generator exercises so it would obviously be running with load if it runs at any other time so just connecting to something that shows the generator is on would be beneficial. You pictures were not clear enough for me to make the connections out. So far my isy program is when the i/o linc is on send an email. I look forward to doing some more testing and trying out your programs.

thanks,

Jim

[ergodic]

Anything with a sense wire should work fine. Just hook the sense line to the generator 120V live wire at the transfer switch. When that comes up it will signal the ISY and your program can do what it wants.

 

You need 120V to power the link, otherwise there will be a delay as the device comes up, and so you'd probably need a more complex program to handle the retries. In my case I have a UPS on the entire ISY system, so it wasn't hard to pull that over.

 

Be careful not to cross-connect anything at the transfer switch - it's a code and really serious safety issue. Just keep everything on the Generac side.

 

What I have has no way to discriminate between the weekly test and a "real" failure; it simply senses 120V from the generator. But that isn't very hard to figure out: if it's Wed. @ 1PM then it's testing. Anything else is "real."

 

It also has no way to control the Generac, which is unfortunate. Possibly a relay to control the transfer switch, but it isn't that important to me to mess with it.

 

The biggest problem I had was that the Generac voltage bounces around for a while until it stabilizes. That will cause you linc to signal on/off/on/off... 6-10 times. And you don't want 20 SMS messages. I (foolishly) fiddled around for way too long trying to get an R/C circuit to manage it, not with much success for all conditions. So I finally just did it in the program set and it works fine. You could easily modify the programs to wait for say, 15 minutes, which would eliminate the test notifications.

[EricK]

I am glad this thread came up. We recently had a generac generator installed and I would like to set something up to notify me if we are on back-up power. Isy is on a ups. In my utility room I have an outlet that is backed up and one that is not. I was considering an io linc plugged into the backed up outlet and maybe a relay (NO) that is fed by the non backed up outlet. When the power goes out, the relay would lose power, closing, turning the sensor of the io linc on. I was thinking of a simple program:

If io linc sensor is on, wait 10 seconds, then send notification.

However, I'm not exactly sure how this will work since the io linc will lose power during the switch over as will the plm. Thoughts on this would be appreciated.

Eric

[ergodic]

I'm not seeing anything that suggests SH has discontinued the inlinelinc relay. It's now a dual-band.

 

http://www.smarthome.com/2475SDB/In-LineLinc-Relay-INSTEON-Remote-Control-In-Line-On-Off-Switch-Dual-Band/p.aspx

 

Possibly you're over-thinking this. Keep in mind you're not actually powering any load with the inlinelinc - just using the sense lead. So connect power, and sense, that should do it as I remember. If you power the inlinelinc from your UPS (and the ISY) then there won't be any interruption during a switchover. That's what I use. I can go dig in the panel if you want more details - it's been a while and my memory on this isn't great. But it was really just a 20-minute deal to wire in.

 

I personally wouldn't bother with an Iolinc - a bit less expensive but IMO too fussy since the inlinelinc relay will do the job out of the box. But of course everyone has their own preferences and it's certainly a way to go.

[Brian H]

The new Dual Band InLineLinc Relay does not have any Sense Inputs like the older ones.

I believe the Micro Modules do have a pair of Sense Inputs.

[jzsjr]

I received my insteon micro on/off switch with sense today and hooked it up and have only tested it twice so far with the generator (in exercise). I'm noticing a great deal of fluctuation with the sense going on and off and the sGenerac.On.State variable changing from 2 to 1 pretty much constantly (not just during the ramp up). I have successfully received two emails of "generator on," so I'm guessing it is working well. I'm just a bit curious if I'm suppose to the see the instability of the sense constantly through the exercise period. Does yours level off after the ramp up and remain a constant variable?

 

Also during the second test my micro on/off sense was left in the on state (after generator cut off). I gues it is acting as a toggle and just ended up in the on position when the generator stopped. Do I need to check the latching mode under options? The other options are Single Line: (off) dual-line and Act as 3way:(off) line high always on; line low always off. There is no documentation for the the sense line other than the diagrams. There are two senses (yellow and purple). I'm using the yellow one.

 

thanks,

Jim

[ergodic]

If the voltage is unstable after the generator's been running for a minute, I'd say something's wrong. What does the scope/meter show for output voltage?

 

The Generac does everything it can to maintain frequency. It will shut down for a serious over/undervoltage condition. If the voltage is chronically unstable when it's running it's because the generator is trying to maintain 60HZ by speeding up and slowing down, which it normally shouldn't do much unless the load changes.

 

That's usually caused by a faulty stepper motor -- an Achilles heel of some Generac models.

[jzsjr]

Hey,

Before when I had a meter on the output I measure 123v. I'm going to try and include some photos to make sure I've got this wires correctly. Here goes.

[jzsjr]

That was not exactly what I was going for. I will try again;-)

Jim

[jzsjr]

Ok. Here are several pictures of my set up. I'm not sure I connected the yellow sense to the correct output but I put it in one of the placed I tested for 120 power when the generator was running. Please let me know if this is incorrect. Like I said before, when I had the meter on the output that I have the yellow wire attached to I was reading 123v. I was looking over the installation manual but will look up online how to test the frequency. Here's to hoping the pictures are smaller and oriented.

thanks,

Jim

[jzsjr]

I also have to say that the generator seems to run fine and when on load TV, electronics and lights work with out issue. I don't think my multi meter does hz so will have to borrow something from work.

thanks,

Jim

[ergodic]

I used that little micro on/off for a Christmas display - they work well with the ISY.

 

Your transfer switch looks different than mine. Maybe a newer model.

 

But yellow on the micro connects to the Generac 'hot' line. Line lead on the micro connects to your UPS power. Neutral is common neutral. Load lines on the micro are not connected. With that, the ISY should detect when the Generac is on via the yellow sense line status change.

 

If it keeps bouncing around after the generator is stable, for sure something's wrong. You can usually tell if it's the Generac - the thing will be speeding up and slowing down a lot for no reason.

 

Not too likely you have a frequency problem. The Generac will do everything it can to maintain 60HZ - even it it means voltage fluctuation. (Same as the power co.) So if the voltage you read is stable after it fires up then I don't know why it the micro would be bouncing on and off. You might need a scope to see what's happening.

[jzsjr]

The generator seems to be running smooth at least to the naked ear. No audible surges etc. I'm still getting the constant on/off during the full cycle but the "on generator" message has never failed to send. I added a small program

If

Status 'GeneratorSense' is not Off

 

Then

Wait 4 minutes

Set 'GeneratorSense' Query

Wait 90 seconds

Set 'GeneratorSense' Off

 

Else

- No Actions - (To add one, press 'Action')

 

Encase my micro on/off sense is left on after the generator stops. This program constantly runs but never gets past the 4 minutes unless the generator has really shut down. I'm up for suggestions if anyone has a more elegant solution. All in all everything appears to work, just a lot of variables and programs switching on and off. I am planning to kill house power tomorrow and test the generator with load.

thanks for all the help,

Jim

[ergodic]

Have you scoped the voltage to see what's happening?

 

Normally the Generac is clean power and I'm wondering if there's maybe a problem with the little micro or noise on the circuit.

[jzsjr]

Not yet. In Atlanta with bad weather. Once I'm back at work I can discuss with colleagues that know more than I do plus access to a scope.

Jim

 

Sent from my Nexus 7 using Tapatalk

[jzsjr]

Ok, I bought a kill-a-watt meter and will try using it to measure the frequency. House current is already showing 60hz. No surprise there. Unfortunately there is a lot going on this morning so I'll have to wait till tomorrow to test house with load. If this is not successful or inaccurate It'll have to wait until I can borrow a meter that can measure hertz or figure out how to use an oscilloscope;-)

thanks,

Jim

[ergodic]

It sounds like something is triggering the micro on/off - the scope will show the waveform so that's probably going to be the most helpful.