DIY Auto Start / Stop Generator Control using Remote

Discussion in 'The Projects Forum' started by Sledgehammer_1, Mar 5, 2018.

  1. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    First time poster, long time lurker. I know there have been many threads about this topic, most of them tend to get lost in the weeds and peter out. Please bear with me, I'm an structural engineer and have a fair amount of experience with 12v wiring and circuit design (automotive). I'm learning the differences of 120/240 design as I go, so forgive my ignorance.

    INTENT: Modify the remote start fob of a Westinghouse WGen7500 residential generator to signal start and stop based on the presence or lack of grid power.

    DESIGN:
    I would like to mirror this setup more or less:
    [​IMG]
    • Auto Transfer Switch (Need suggestions on affordable ATS)
      • ATS will switch to Generator power when:
        • Grid Power is lost
        • Generator power has come on line
      • ATS will switch back to grid power when power is restored
      • I came across this ATS which fits the bill just not my specs. Not interested in a questionable Chinese component, however the function is exactly what I am looking for.
    • Westinghouse Wgen7500 PDF Manual for reference

    WHERE I NEED HELP:
    The above one line diagram is a great start but it is lacking the portion of the circuit which would make this a automatically controlled system. I believe it would be as simple as hacking the controller so that upon grid power loss the "Start" button is triggered and released once power production has come on line. Then when grid power is restored the stop button would be triggered and held until generator is shut down fully.

    I could use some help and ideas on how to design a circuit that can facilitate the above processes. To me it seems as though it can be accomplished in a low volt circuit utilizing power sensing relays etc.

    Ultimately I am not worried about having the remote remain 'mobile', meaning that I can hack it, solder in the circuit and power supply then have it set in some location within the house as the 'control unit'.

    Thoughts?
     
  2. Reloadron

    Distinguished Member

    Jan 15, 2015
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    I think as you get into this you will find there is more to it than simply a transfer contactor. You do not want your generator trying to start on a simple power interrupt so between loss of mains power and generator start you want a delay. My system waits about 5 seconds and then attempts a generator start. Once the generator starts it waits about 5 seconds for the generator to come up to speed and then initiates a transfer on the contactor. If at any time mains power returns during that process it will ignore it. Once transfer has happened the whole house is on generator power. I am running a natural gas fired 18 KW system with a 200 Amp transfer contactor system. The battery is always maintained using a battery maintainer circuit and the system runs once a week for about 20 min exercise routine but on exercise does not transfer.

    Fully automatic transfer can be eliminated and everything done manually but I gave that up about a decade ago. Anyway my experience was it was easier to buy an off the shelf turn key solution rather than build one. My system at work was a three phase 480 Volt 60 Hz, 250 KW system driven by a huge Cummins Diesel and it worked about the same. Part of the delays involve knowing the generator set has actually started, knowing it is up to speed and when to initiate a transfer.

    What you have is a Westinghouse 7.5 KW generator set. With a plan to use this during power outages for emergency power This is your generator set. The unit has some nice "smart start" features in that it will auto start when holding your key fob button down for I think I read one second. There is a green light which illuminates once starting is complete. You may be able to use that signal to begin a short delay of about 5 seconds and then pull in a transfer contactor. You are only looking at about 240 VAC @ 30 Amp so all you really need is a 50 amp contactor now you will need larger depending on how you go about this and what your residential mains service is? You also do not want the generator coming up under a load which is another reason for a delay. After mains power returns and after transfer back to mains power you want to give the generator a cool down period. At least 60 seconds would be a guess.

    I would like to know more about the smart switch outlet? It apparently allows connection to a Westinghouse WHMTS30A 210052 30 Amp Manual Transfer Switch not exactly an inexpensive accessory. I see them on Home Depot and Amazon and other retailers. They also sell the generator to switch cable. You can have as much or as little automation as you like? I will give you a word of caution as working with 240 VAC US Residential service is not extremely dangerous it will put a hurt on you so always make sure you are working on deenergized circuits.

    Ron
     
  3. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    Right I understand that a delay is critical. I should probably say that I currently work as a large scale commercial GC project manager so I have a fair amount of experience reviewing designs and understanding high dollar auto gentrans units (every school, hospital and fire stations I've built is getting them). Literally just installed a 240 service into my garage for the welder today.

    The auto transfer switch in the video fits the bill well, it only begins its switchover once the generator has come up to service voltage. Just not a fan of products made out of chineesium.

    I also understand that most services will try to kick back up 2-3 times if there is a ground fault before kicking out entirely. So the delay is certainly necessary.

    This could be accomplished by having a undervolt / loss of freq. detecting relay trigger a simple adjustable delay on relay. The delay relay would count down to 5 seconds then if grid service hasn't returned it would activate the remote start button.

    The plan is to have a maintainer on the battery as well.

    The cool down period could be commanded by another time delay off

    Grid service is single phase 3 wire. 120/240 1P 60Hz

    Thanks for your advice Ron, I've appreciated your input. Totally get the safety factor, I've got a line up of well used fluke meters in my tool box that help keep me deenergized.

    I still think that some basic electrical components combined with the correct logic can make this happen. Perhaps I should just map out some ideas on my circuit generator.
     
  4. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    I might try something via arduino. I have several programming buddies that could help me out
     
  5. Reloadron

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    Jan 15, 2015
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    That is where I would begin. A clean sheet of paper and work out the logic. Arduino or any similar micro-controller would be a good start also. All you really have is a small pile of logic for your friend to muddle through. :) Fortunately the manual has a pretty good schematic to assist and if you can just find a mating connector for that front panel remote connector you may be able to use that in your favor. Also beyond a micro controller there are canned timing solutions available if needed, a Google of timing relays should help there. One more detail is in the manual take note of the comments regarding "bonding" as to where and how it is used,

    Should you have any further questions just ask, no shortage of help in these forums.

    Ron
     
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  6. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    Here are some simple circuit mock ups I developed for the auto start stop controller. It's simplified and I assumed the remote will operate on 5v DC. The battery system will be maintained by a 120vac -> 5vdc wall pack. The photos below are in sequence starting with grid power, simulated outage, start up sequence. Then the Shut down circuit is shown.
    Screen Shot 2018-03-06 at 9.02.30 PM.jpg Screen Shot 2018-03-06 at 9.03.30 PM.jpg Screen Shot 2018-03-06 at 9.04.25 PM.jpg Screen Shot 2018-03-06 at 9.10.19 PM.jpg Screen Shot 2018-03-06 at 9.14.42 PM.jpg Screen Shot 2018-03-06 at 9.20.39 PM.jpg Screen Shot 2018-03-06 at 9.21.52 PM.jpg

    Thoughts?
     
  7. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    AUTO START CIRCUIT:

    Relays:
    S1) Normally Open, delay close ~5 sec
    S2) Normally Closed
    S3) Normally Open, pulse 2 sec Closed, 5 sec open

    Circuit Logic:
    · IF Main Service is ON THEN S1 remains open
    /end (Normal Operation)

    · IF Main Service is OFF >5 seconds THEN S1 will close (Delay 5 sec)
    · THEN S2 remains closed
    · THEN S3 is triggered and closes
    · THEN Westinghouse Remote “Start” circuit is triggered
    · IF GENSET energizes S2 THEN S2 opens
    /end (gen start sequence)

    SHUT DOWN CIRCUIT
    Relays:
    Sd1) Normally Closed, delay close ~5 sec
    Sd2) Normally Open
    Sd3) Normally Open, Delay Close 5 min, pulse close 2 sec, 5 sec open

    Circuit Logic
    · IF Main Service is OFF Sd1 Remains Open
    /end (normal operation during outage)

    · IF Main Service is restored THEN Sd1 will close (delay 5 sec)
    · THEN Sd2 remains closed
    · THEN Sd3 initiates 5 min delay
    · IF Main Service remains uninterrupted THEN after 5 min. Sd3 closes
    · THEN Westinghouse Remote “Shut Down” circuit is triggered
    · IF GENSET circuit de-energizes THEN Sd2 opens
    /end (Shut down sequence)
     
  8. Reloadron

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    Jan 15, 2015
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    That was a nice job. At a glance it looks like it should work. Keeping in mind it is a rough. Your friend who is familiar with an Arduino can put your program logic I am not a programmer type, I have played with it and did just enough of it to survive before I retired but that is it. I see it as mostly boolean on digital in channels which produce actions on digital out channels. Again, nice job on the schematic(s) and outlining the logic flow. Hopefully another member here may have something to add?

    Ron
     
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  9. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    If I can source relays that fulfill those functions then I could prototype these circuits on my bread board. If they work I could build the board and implement it without arduino.

    Can you guys help me source relays that meet the requirements listed above?
     
  10. Reloadron

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    Jan 15, 2015
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    As to the relays. Rather than 5 VDC coils you may want to consider 12 VDC coils. That opens the door to using some automotive relays and a wider field from other sources. DigiKey is one good parts source. Relays made by Omron, Magnecraft and others are good manufacturers,

    Digi-Key

    Allied Electronics

    You may also want to consider a Google of Relay Boards or 5 Volt Relay Boards which will get you to plenty of turn key boards with relays including all sorts of relays. That also includes relay boards from distributors like Amazon.

    Ron
     
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  11. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    Thanks Ron,

    I agree that 12vdc is a better platform for the circuit. It opens up the door to a ton of products and its easier to set up a solar maintainer.

    This relay popped up in a google query, looks like it could fit the bill for relays in both circuits (perhaps even reducing the number of relays needed).

    While they are Chinese I've had experience with similar boards and was actually impressed with the quality and functionality. The biggest hurdle is trying to understand the instructions which are all poorly translated from chineese to some form of english, but I guess you accept that challenge when you are getting all that functionality for a fraction of the cost.
     
  12. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    I designed the circuit around 5vdc because thats likely the operating voltage of the westinghouse remote. But thats dumb, I can easily drop 12vdc to 5vdc via a zener diode.
     
  13. Reloadron

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    Jan 15, 2015
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    On this note you really do not want to use a zener diode, you would do better to just use a 5 volt regulator like for example a LM7805 which will afford a stable 5 volt supply voltage up to about 1 amp. There are a number of reasons a zener is a poor choice but we won't get into them, take my word for it. :) Now if you plan to incorporate a micro-controller for the decision making and timing the Arduino will run off an external 5 volt supply and make its own 5 volts. Any digital out from the Arduino is 5 VDC logic which can easily drive any 5 volt logic level MOSFETs which can in turn switch any relays. The genset itself has a 12 volt battery which is maintained by a battery maintainer (trickle charger). So you have 12 VDC readily available.

    The relay you linked to could likely use the under voltage protection feature to detect a loss of mains power and include a delay so maybe yes, add a 12 volt DC wall wart and set the limits. My Experience with the Chinese stuff has been OK, and I agree that Chinglish is a difficult language. :) Before retiring I would never consider the stuff as I worked with Naval Reactor Systems but now for home projects I have no reservation with using the stuff. Unfortunately the relay you linked to does not have a data sheet but most of this stuff doesn't. Then too the stuff with data sheets has a heck of a price tag.

    Ron
     
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  14. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    You're right, I just thought about the issues with using a zener. Not to worry though I've got plenty of LM7805's on hand.

    I bought three of them, at that price if they work sweet if not then I have something to play with.
    I've got my buddy looking at my logic and mapping what it would take to have arduino handle this circuit. If its reasonable I'd like to go that route because then I can add features like circuit time out (in the event the genset doesn't start), wireless control & monitoring of many many parameters.
     
  15. KeepItSimpleStupid

    Distinguished Member

    Mar 4, 2014
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    There should be a lot of stuff here: http://www.ascopower.com/en-us/products-catalog/products/power-transfer-switches/

    We has a 30 kW Kohler generator at work. Pretty basic except that it has to supply all of the 3 and single phase voltages used at work. From 460 3 phase, 277 single phase, 208 3-phase and 120/208 single phase. I never saw the local panel, or if there is one, just the transfer panel.

    There's the standard low oil level, water temperature, within frequency limits, RPM, voltage, current within voltage limits. There is load sheading (turn off AC) that sometimes can be done.

    Reading at the transfer switch or web intergace and not the generator makes sense.
     
  16. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    Thanks KISS. That site seems to be geared more towards industry but cool components regardless.

    I'm looking at this ATS: PMTS-50

    Looks well made and delays 20-30 seconds to allow vac stabilization. That means I can simplify the auto start circuit slightly by just using a regular relay sensing the grid power instead of one that delays close 5 seconds.

    If I understand the operation correctly it will work in my system nicely.
     
  17. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    But then again this might be a more robust solution. Looks more involved but might be a better finished product. Plus I might be able to use it as the signal to start either circuits operations.

    Got to look into it further tonight, what do you guys think?
     
  18. KeepItSimpleStupid

    Distinguished Member

    Mar 4, 2014
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    My intention with the ATS website was to make you aware of what you need to check.

    ..

    The youtube video is a bunch of garbage, They are not mechanically interlocked. The manual one even can just continue traveling and not stop at off before allowing a move to the other position. I'm confident that they would flunk inspection in the US.

    ..

    DIN rail construction for process control is the standard.
     
  19. Reloadron

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    Jan 15, 2015
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    An ATS like above is what you really want. The idea being there are two relays which are mechanically linked so they can't be energized and close together. When mains commercial power meets generator it gets ugly. :) Using an ATS like you posted precludes that happening.

    <EDIT> I see KISS covered it as I typed. (</EDIT> :)
    Ron
     
  20. Sledgehammer_1

    Thread Starter Member

    Mar 5, 2018
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    Thanks, however you provided a link to the ATS product page (only 1 of which is 1p 240v 3 wire) of a commercial / industrial suppliers website without any further info. I didn't invest much time past that on that site attempting to self educate.

    I am just now starting to look into the ATS side of the equation since I have a pretty solid handle on the auto control aspect so I am still learning. Yet I do know that I don't want to have a crap ats that can allow both contactors to be energized and closed at the same time, interlocking is a must.

    Thanks for this snippet of info but would love it if you could elaborate. If you reference the OP you will see that I am not a career electrician, however I am not a bumbling idiot who doesn't understand the fundamentals of electricity.

    Which ATS are you referring to as the one I want? I'm assuming the PMTS-50?
     
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