New 18KW air cooled unit - was 58Hz now 60Hz

[SkipD]

I just had a model 5416 18KW (16KW on natural gas) generator installed last week. When we fired it up, it ran at 58Hz ±0.2Hz both at no-load and under load. Adjusting the voltage regulator had absolutely no effect on the frequency (as the manual said it should have). My dealer contacted Generac and got information that, when implemented, fixed the problem. It now runs at 60Hz ±0.2Hz, both at no-load and under load.

The fix was to change settings on a 4-position DIP switch on the controller board. The controller board is assembly # 0G5715, Rev B (with software 0G5924, Rev B, date code 0743) and is mounted under the control panel. The original settings for the DIP switch (positions 1/2/3/4) were off/off/off/off, and now are off/on/off/on.

Position 1 of the DIP switch affects the low speed exercise option (on = full speed exercise), according to the manual. I don't yet know the details of the other three DIP switch positions, but I am working on getting that information.

[mike_y]

Thanks for posting this, SkipD. I find this very interesting as I also have a 5416, installed 10/07. Generac's "Installation and Owners Manual [for] 7, 10, 13, 16 & 18kW Air-cooled ... Generators" gives 0G5715 as the part number for the controller assembly and this is what I have, I don't know the software version. This may be the "60 HZ" PCB Kelly Myers referred to in a post ("So who wants to be a guinea pig ...") in the "Air Cooled" forum 11/14/07. I don't have a frequency meter but the Tiny Tach says my 5416 runs at 3480 RPM, which works out to 58 Hz. I opened it up and looked at the dip switch block and sure enough there are 4 switches, all set "off". But before I begin flipping them I'd like to know a bit more about what I'm doing. Why do they need 2 switches to set 60 Hz but only one for low-speed exercise? Are 2 different functions actually being modified? What do the other switches do? 4 switches gives them 16 possible codes; do any of the others mean anything? Why didn't Generac make the 60 Hz option the default? Is there any downside? I'll be very interested to see what information you can get. And thanks for this pioneering discovery. No Generac documentation I've found and nothing I've seen in the forums even mentioned that there were 4 dip switches on the 5416.

Note to Kelly Myers: Shouldn't this thread be transferred to the "Air Cooled" forum?

[SkipD]

Mike - I am trying to get documentation from Generac describing the control board and its setup. I was unsuccessful calling in as a customer, and am trying through my dealer. If that does not pan out, I will contact a friend who is the VP of Engines at Generac.

I suspect that the speed setpoint (the desired speed value) is controlled by three of the four DIP switches, leaving switch position 1 for the low-speed exercise option. However, I will post the details when I get them.

Look at the control board and you will see stickers that show the revision of the board and the software revision. If yours is the same as mine, then pull the fuse out (near the auto/off/manual switch) and then change the two DIP switch settings. If you don't pull the fuse (or disconnect the battery), the DIP switch will probably not be read to implement the change in settings. Then reinsert the fuse and test run the generator. Not only do I read 60Hz on my meters, but my Tiny Tach hangs in right at 3600 RPM.

You will have to re-set the exercise time after having pulled the fuse.

[SkipD]

I got some limited information about the DIP switch settings on the controller board in my new 5416 (see my first post for part number etc.) from my dealer.

DIP Switch Status Function
1 ON Normal (full speed) exercise
OFF Low-speed exercise

2 ON 60 Hz
OFF 50 Hz (this I am not sure about, as off is default setting)

3 OFF (Spare - off is default setting)

4 ON 60 Hz steady
OFF 58 - 61 Hz

I hope this is helpful for folks with generators like my 5416 (probably those produced after about October 2007 based on my analysis of what looks like a date code).

I will be going to my friend at Generac who is in a position to get me engineering document information if he cares to do so, and may get more details.

[mike_y]

SkipD, I opened up my 5416 again and checked the controller assembly and software versions and they were the same as yours, 0G5715 and 0G5924, Rev B. So I pulled the fuse, flipped dip switches 2 and 4 on, shoved a camera in under the control panel to record what I had done (that switch block is pretty well concealed behind jungles of wires), put the fuse back in and started it up on manual and the Tiny Tach indeed showed 3600 RPM, very stable. I reset the exercise timer and it did an exercise run at 2400 RPM, as it should. I pulled the utility breaker on the transfer switch and the generator started up in due course, 3600 RPM, and the transfer switch responded correctly. The line voltage was a bit high, 130 VAC as against the normal 120 VAC, under light load, but it had been a bit high at 3480 RPM too. I started a 5 KW electric drier and the voltage dropped to 120 VAC. When I shut down the drier the power dipped for a second but then quickly came back to 130 VAC; it had done this at 3480 RPM too (I think the voltage regulator and the engine governor don't respond equally quickly). I don't have a frequency meter but I checked the sweep second hand of an old analog electric clock against my quartz watch and they seemed in sync. So thanks again for your pioneering discovery.

In your most recent post, I'm puzzled by switch 2 ("ON 60 Hz OFF 50 Hz") because the generator ships with this off and it runs 58 Hz. I suppose switch 4 permits tradeoff of steady frequency for something else: perhaps more constant voltage? I'll be interested in finding out more.

[SkipD]

Mike - all I did was pass on information as it was given to me by my dealer. I will hopefully be going through my friend to talk to the engineering staff at Generac to get the real truth about the board setup. Assuming that I make the needed contact, I will definitely post the results.

You can lower the voltage easily by adjusting the little potentiometer in the middle of one of the modules toward the rear of the generator housing from the control panel. The module is the one at the right of the two similar shaped modules if you are standing in front of the generator. Merely tweak and measure while the generator is running. I would suggest setting the voltage to about 248V across the two main terminals in the breaker.

[mike_y]

Originally Posted by SkipD

DIP Switch Status Function
1 ON Normal (full speed) exercise
OFF Low-speed exercise

2 ON 60 Hz
OFF 50 Hz (this I am not sure about, as off is default setting)

3 OFF (Spare - off is default setting)

4 ON 60 Hz steady
OFF 58 - 61 Hz

Let me take a wild guess. Switch 2 doesn't do anything unless switch 4 is set (steady frequency). Then Switch 2 selects between steady 60 Hz (most of the Americas) and steady 50 Hz (most everywhere else). If switch 4 is not set switch 2 is ignored and the generator reverts to the 58-61 Hz range of the older Generac systems, rising with increasing load. I'll be interested to see the real story.

[mike_y]

Originally Posted by SkipD

DIP Switch Status Function
1 ON Normal (full speed) exercise
OFF Low-speed exercise

2 ON 60 Hz
OFF 50 Hz (this I am not sure about, as off is default setting)

3 OFF (Spare - off is default setting)

4 ON 60 Hz steady
OFF 58 - 61 Hz

A Diagnostic Manual including the "16 kW NG, 18 kW LP" air cooled generator, presumably the 5416 though it doesn't seem to use model numbers, has now appeared on Generac's manuals page, http://www.guardiangenerators.com/Products/Manual.aspx. The manual is part number 0g4338, Revision C, dated 06/08. It may be downloaded (PDF, 10.1 MB) at http://www.guardiangenerators.com/Pu...0g4338revC.pdf. The drawings actually show the 4-position dip switch, with the functionality as posted by SkipD. This is the first public documentation from Generac that I've been able to find that even mentions the existence of the 4-position dip switch, though only in the figure on Page 78 and in Drawing 0F7822-A on page 142; nothing in the text.

[SkipD]

Originally Posted by mike_y

A Diagnostic Manual including the "16 kW NG, 18 kW LP" air cooled generator, presumably the 5416 though it doesn't seem to use model numbers, has now appeared on Generac's manuals page, http://www.guardiangenerators.com/Products/Manual.aspx. The manual is part number 0g4338, Revision C, dated 06/08. It may be downloaded (PDF, 10.1 MB) at http://www.guardiangenerators.com/Pu...0g4338revC.pdf. The drawings actually show the 4-position dip switch, with the functionality as posted by SkipD. This is the first public documentation from Generac that I've been able to find that even mentions the existence of the 4-position dip switch, though only in the figure on Page 78 and in Drawing 0F7822-A on page 142; nothing in the text.

Thanks for the links. I'm downloading the document as we speak.

I still have not gotten any straight scoop from Generac. My friend - who had been the VP of Engines - no longer works at Generac. Even so, I got hooked into a tech in Customer Service but the lines he fed me left me totally unsure of the facts. I have asked my dealer to straighten out the facts. I don't want to get into the suspected BS here, but when I finally get the truth I will publish it.