Blink
Does anyone know if the SMMs are compatible with portable/manual transfer switch installations? Understanding that they monitor frequency, I don't see why they would not, but wanted to make sure...thanks
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Birken Vogt
The caveat with a SMM is that the frequency has to decrease for it to work unless you are using the generator lockout function.

If the generator engine has more power available than the windings can handle, then it might never drop out.

I believe Generac has their generator's computer (which senses load digitally at the load wires) lower the frequency to 58 Hz on the latest iteration to force the SMMs to trip even if the engine still has enough power, if it sees an overload and wants to drop load.

Portables will not have this function, and may or may not drop load when appropriate, but when grossly overloaded, it should always drop fine.
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Blink
...I do plan on using the lockout feature- so it sounds like it will work. Thanks
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Birken Vogt
Blink;48475 wrote:
...I do plan on using the lockout feature- so it sounds like it will work. Thanks


The lockout feature looks for any wavering frequency which is not 100% stable like the grid [normally] is. So it will work fine for that.
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BillM
Birken Vogt wrote:
The caveat with a SMM is that the frequency has to decrease for it to work unless you are using the generator lockout function.

If the generator engine has more power available than the windings can handle, then it might never drop out.

I believe Generac has their generator's computer (which senses load digitally at the load wires) lower the frequency to 58 Hz on the latest iteration to force the SMMs to trip even if the engine still has enough power, if it sees an overload and wants to drop load.

Portables will not have this function, and may or may not drop load when appropriate, but when grossly overloaded, it should always drop fine.


I installed an EVSE last year, 50A circuit to a 40A EVSE (JuiceNet 40+).  My generator (22kW) in my house should be able to take on the EVSE without a problem but because I overdo stuff I shouldn't overdo, I put the Generac SMM in, it's the 6873 model, I believe a 7000 is out now.  My plan was to utilize the lockout switch (on) so that the EVSE was locked out under generator power.  In my real world it never does.  I do not have a Fluke with the proper lineage to measure Hz.  But my meter does measure Hz and it shows 59/60 under generator and mostly 60 under utility.  If I'm understanding my years on this forum, absorbing knowledge, then my SMM is operating as designed, and my generator is giving me power too close to utility.  Again, based on a meter that is not to be fully trusted but it's all I have.  Any thoughts?  Is this something I should just live with and assume that if the generator gets overloaded it will shed the EVSE at that point?  The SMM is under warranty, but I self installed so I don't know how Generac helps consumers working outside the realm of a dealer.

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murphy
What car? 

A Tesla ramps up starting at 1 amp while monitoring the voltage.  Increasing a couple of amps at a time the generator should not have any problem staying with the increase.  However if the Tesla sees an abnormal drop in voltage it will stop increasing the current.  If you have a Tesla I would be very surprised if the SMM ever trips.

This is totally different than an air conditioner compressor that slaps 6 to 7 times the running current on the generator to get the compressor turning.  That said my 20 kW generator easily handles the start of a 3 ton air conditioner that has a soft start controller installed in it.
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BillM
I have the Chevy Bolt, not Volt.  My car wasn't plugged in at the time.  But I was on generator.  I walked into the garage and I noticed the EVSE had power.  My understanding was that the Generac SMM was supposed to detect that I was on generator power and to respond per the settings I have the SMM set at.  The SMM would shed the load if the generator was struggling, but it would also delay start the load based on the number of minutes set in the priority dial.  BUT, I had the lockout switch enabled.  That means that the SMM should have locked out the load, the EVSE, regardless.  That was my understanding.  My intent was to lockout the EVSE at all times.  I 'believed' that the SMM would lock out regardless of generator state/load or anything.  That's what I wanted.  I was lazy, so I went the SMM route versus running a control wire to the garage for a PMM.
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BrentB
If it wasn't set to "LOCKOUT" before being powered on, it won't lockout. The board only reads settings once during power up.
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BillM
The SMM has always been on LOCKOUT.  I'm going to borrow a proper meter and retest.  My meter, which is not proper, shows 59Hz while under generator.  My setup is I have a 50A breaker in a load center going directly to the SMM.  A JuiceNet+ 40A (EVSE) is hard wired directly to the SMM.  The SMM lockout switch is set to LOCKOUT and the priority switch of the SMM is position #1.  It is my only SMM.  I have a Generac 22kW with ATS.  I can reproduce my situation 100%.  I drop the house power via the ATS main.  The generator starts and eventually takes the house load.  The house was dark for about 15 seconds'ish.  The base shed timer on the SMM is about 5 minutes, after about 5 minutes while still on generator, the SMM provides power/energizes the EVSE.  I have no car connected, so there's no effective load.  But I get dancing lights on the EVSE, it connects to the house WIFI and emails me it lost power but is back on.  My original intent was to always shed the EVSE, I like the idea of the SMM because if I change my mind, I could simply disable the lockout button and I would get the best of both worlds.  And still supposedly have protection, etc.  Pipe dream.
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grsthegreat
That is odd, because i have installed lots of SMM modules and when i use the lockout enabled feature it has always done the intended job. My biggest pet peeve was the stupid SMM doing a lockout when it was under utility power. I have had this issue many times. I no longer install them with lockout enabled.
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BillM
grsthegreat wrote:
That is odd, because i have installed lots of SMM modules and when i use the lockout enabled feature it has always done the intended job. My biggest pet peeve was the stupid SMM doing a lockout when it was under utility power. I have had this issue many times. I no longer install them with lockout enabled.


IF my understanding is correct that the SMM is looking at the Hz of the power coming in, and drops the load at 58 or less ..... and if my generator is supplying power at 59 Hz, that's my issue.  I know the NEW SMM that came out recently has a mode for dirty utility power, but beyond that the new model doesn't change anything for me.  I don't think my SMM is broken, based on my limited testing.  I'm going to do more testing when my electrician arrives this week.  I don't know if there is anything worth or easy to do about this right now.  I am going to try to see if I can get the SMM to drop by hitting the generator with as big a load as I can.  I will feel a little better if I see it drop the EVSE load under duress.  But that was NOT my intent.  I wanted to drop the EVSE at all times.  I chose the SMM because I blindly believed in it.  In hindsight I should have installed a PMM.
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Cobranut
I don't understand why you want to disconnect the EVSE if the generator isn't overloaded.  Why not let it charge the car if it's running anyway and has the capacity?
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BillM
Your question is fair and I honestly have no reasonable answer.  It's my commuter car, so it's not my only car.  I just figured for a short power outage, why burden the generator for a not critical application.  And, Level 2 Home EVSE's just literally pass the power through to the car.  They are barely anything more than a latching relay.  The actual 'charger' and all the circuits for doing that is IN THE CAR itself.  My thoughts (based on nothing scientific) was to 'protect' the car from any transient power/surges/spikes or anything that the Guardian 22kW Air Cooled is going to pass on.  That's really the best I have, and it isn't much for trying to rationalize my plan.
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Mattyman
I believe at some point the lockout feature was changed. Previously, when lockout was enabled, it would never allow the load to come on when on standby power. The logic was then changed to allow the load to try and turn on and if it handled the load it would stay on. It would only lockout the load after that load caused an overload condition.

I recall experiencing this a few years ago with an installation where the load was set to lockout bit it still came on. Had to reread the manual and see that it was changed. Maybe this is what is occurring in your situation.
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BillM
Mattyman wrote:
I believe at some point the lockout feature was changed. Previously, when lockout was enabled, it would never allow the load to come on when on standby power. The logic was then changed to allow the load to try and turn on and if it handled the load it would stay on. It would only lockout the load after that load caused an overload condition.

I recall experiencing this a few years ago with an installation where the load was set to lockout bit it still came on. Had to reread the manual and see that it was changed. Maybe this is what is occurring in your situation.


Hmmm, that changes things dramatically.  I tried to test for this.  While under generator, and the SMM charging my car I kicked on the air conditioner for the house, a 5 ton.  It does not have a hard start capacitor so it dimmed everything .... and the SMM didn't lockout.  In my unprofessional opinion, I would have expected the SMM to cut out the car when the HVAC kicked in.  It didn't.  I contacted Generac via their website and they directed me to contact a dealer to do a warranty replacement or exchange of the unit.  I explained that it is a retail purchased unit, not dealer purchased.  They wrote me that it does not matter where I got it, a dealer can do a warranty exchange or service on it.  So, I'm going to see where this takes me I guess.  I don't need anyone to do anything, just an exchange is all I need.
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BillM
Mattyman wrote:
I believe at some point the lockout feature was changed. Previously, when lockout was enabled, it would never allow the load to come on when on standby power. The logic was then changed to allow the load to try and turn on and if it handled the load it would stay on. It would only lockout the load after that load caused an overload condition.

I recall experiencing this a few years ago with an installation where the load was set to lockout bit it still came on. Had to reread the manual and see that it was changed. Maybe this is what is occurring in your situation.


For what it's worth, page 9 of the owner/installation manual has a testing procedure for being on lockout, and it makes no reference to a load condition being a trigger.  It's black and white; turn the service disconnect off.  Things go dark.  Generator starts.  "For modules with lockout switch enabled, LED's will flash at 6 second interval and load will remain disabled."  Now, if the manual hasn't been updated, that sucks.  The manual is Rev e / 1/20/2015.
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Mattyman
It was on a separate sheet included with the SMM owners manual. I believe it had two notes indicating changes in the behavior. I'll see if I can find one. I haven't tested it since with the old normally open or the new normally closed contactors.
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Mattyman
Here is the information I found in with the SMM manual.
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Goofy4TheWorld
BillM I think Mattyman has your answer in black and white.  The "lockout" mode no longer means LOCKOUT unconditionally, and the only way you could accomplish what you want is to find an OLD SMM that behaves the way you want it to!

I think that is a crappy change for Generac to make myself, and I competently agree with your logic to shield the car from the generator's inevitable sub-par power if you can help it.

I can see the value in the "lockout ONLY if there is an overload" mode, but it shouldn't come at the expense of the full-lockout mode, it should be something you can select.  Many folks don't want to stress things with an overload if they can help it.  Using the old-style lockout was an easy way to shed things like pool pumps etc.
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BillM
Thanks guys.  What @Mattyman has was not with my SMM.  I have the box and docs.  I completely agree that it seems to be operating as the addendum states it.  Which to me, seems to negate the switch completely.  This is what I expected/wanted. SMMPG4.jpg 
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