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Powertech Generator starts at 124V but then drops to 110V after 20 minutes

July 18, 2020, 07:51:03 pm

We have an 8kW Powertech generator that produces 124v (on both legs) initially. After a generator warm up period, turning on both (not at same time) AC units drops the voltage to around 120v. After running the electrical load for 20 minutes the voltage drops down to 110-114v. Any idea why the generator is not able to maintain the initial load voltage?

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #1 – July 18, 2020, 08:02:00 pm

We can speculate but best choice would be call and talk to Jeff at power tech for the best answer.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #2 – July 18, 2020, 08:18:39 pm

My 12kw had the same problem. They will tell you if you locate your voltage regulator there is a very small brass screw if you turn it clockwise or counter clockwise you can adjust your output voltage. Mine would adjust but then would loose voltage again. I had to buy another voltage regulator to fix it. I was looking for my old one to attach a picture to show the adjustable screw but I threw the old one out.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #3 – July 18, 2020, 08:24:32 pm

Thanks. Was it difficult to replace? Since it is dropping voltage I assume a replacement would be in order.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #4 – July 18, 2020, 08:51:24 pm

Video of 12KW
8kW Powertech generator voltage regulator video - Bing video

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #5 – July 18, 2020, 09:33:32 pm

Shared album - mark hubbard - Google Photos

This is my 2019 plug and play 8k Powertech regulator.  You can see the adjustment pot. By expanding on photo.

Note: those with larger Powertech generators will have the VR that have wires that have to be moved.  Be aware.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #6 – July 18, 2020, 09:47:32 pm

Replacement.

1. Pull generator forward.
2. Remove cover from control box on left. Take picture inside box on horizontal. Check that it's not blurry.
3. locate Vr in right rear corner.
4. Remove plug
5. Remove screws holding Vr down.
6. Install new Vr.
7. Plug back in plug on Vr.
8. Before you start. Gently check any and all connections. Looking for loose, chaff, dead bugs, etc. Fix as needed. Check coolant, oil levels.
9. Turn off ac units. Start generator. Allow to run. Go look at voltage monitor or have partner look and be on communication with you. If not at 120. Take small flat tip. Slowly turn screw. Noting up/down of voltage. It moves fast. Adjust to 120. Wait a few minutes. Turn on ac units. Note voltage read out. Should be stable at 120. If below 120, adjust to 120. Doubtful it will be.
10. Turn off Ac units. Turn off generator. Look over inside control box for last time. Cover back on.
Check fan belt for tightness. Look over generator for leaks, bullion, chaff, cat that likes heat.
Slide gen back. Do snoopy dance ( raise head toward sky, dance in circle holding head up) hysterical laugh is an option. You just saved $400.00 labor job.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #7 – July 18, 2020, 10:21:08 pm

Thanks you guys very much! Great info.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #8 – July 18, 2020, 10:23:13 pm

Where are you checking you voltages at. Try checking them at the transfer sw under the bed. Mine was doing the same thing turned out to be loosing It through the transfer sw, bad contacts.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #9 – July 18, 2020, 11:19:23 pm

Several folks have blown up their generator trying to replace the VR.  Take the job very seriously. 

https://www.youtube.com/watch?v=p4tixm-kn00

Also when I first started voltage was very low and I had to adjust the adjuster screw a VERY tiny amount to get it to 120v.

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Re: Powertech Generator starts at 124V but then drops to 110V after 20 minutes

Reply #10 – July 19, 2020, 01:30:34 am

Jeff told replacement VR would need rewiring during the install.  Otherwise you may let out expensive smoke

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