Over Speed light flashing on a 43903

Generac, Guardian, Honeywell, Siemens, Centurion, Watchdog, Bryant, & Carrier Air Cooled Home Standby generator troubleshooting and repair questions
Post Reply
majewskitj
New Member
New Member
Posts: 3
Joined: Mon Jul 01, 2019 4:35 pm

Tue Jul 02, 2019 8:20 am

 Mon Jul 01, 2019 9:16 pm

- Fuel supply type (NG or LP), size of pipe and length of gas run: Natural Gas
- Model and Serial number of generator: 0043903 serial # 3943934
- Problem you're having, what have you done so far to try and resolve the issue : Over Speed Light flashing
- Do you have access to testing equipment such as a digital volt meter and fuel pressure gauge: Yes
- How long has the problem been happening, during cold/warm weather? Two weeks
- What has the maintenance been like for the generator (a lot of problems are due to a lack of maintenance): Oil change / Oil filter / check air filter - clean. Have not done anything with the spark plugs

Gen Set went through normal weekly exercise cycle and have the over speed light flashing. Checked the measured Ohms on voltage regulator (wires 0 and 4) got 23.4 Ohms across. Red light goes on at voltage regulator while engine starts and runs. Disassembled to brushes and slip rings. Cleaned slip rings with brake cleaner and 320 emery cloth. Did not do anything with brushes but made sure the springs were working and still had a lot of graphite left on them. Reassembled and fired gen set up and still get the over speed flashing in manual mode. Any ideas of where to go next? If it is to replace the ignition coils what is the part number that matches this engine? Any help would be appreciated.

Thanks,

Tom
Chris
Site Admin
Site Admin
Posts: 468
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Tue Jul 02, 2019 9:06 am

Hey Tom,

What is the voltage output on the unit when it's running and goes into flashing overspeed?

Thanks for starting the new topic also, I removed the other one :cool:
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
majewskitj
New Member
New Member
Posts: 3
Joined: Mon Jul 01, 2019 4:35 pm

Tue Jul 02, 2019 8:51 pm

During the 10 sec it spiked at 44V and went to zero by the time it shut off. Checked the Excitation circuit breaker with ohms and it is open no continuity.
Chris
Site Admin
Site Admin
Posts: 468
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Tue Jul 02, 2019 10:10 pm

A bad DPE breaker would certainly do it, however the LED would not be lit if the DPE breaker were bad. A bad AVR may have wiped out the DPE breaker
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
majewskitj
New Member
New Member
Posts: 3
Joined: Mon Jul 01, 2019 4:35 pm

Wed Jul 03, 2019 9:18 am

So is your recommendation to buy the DPE Breaker and a Voltage Regulator? Is there any test that can confirm the voltage regulator is bad especially knowing the DPE is bad or does the DPE have to be replaced first and hope it does not get fried by the voltage regulator when generator is put in manual mode? Does Gentek sell these parts? I put in the part numbers from the owners manual and do not get any hits.
Chris
Site Admin
Site Admin
Posts: 468
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

Wed Jul 03, 2019 3:50 pm

If the AVR has the white colored plastic adjustment screw, I would change it out for the one listed below with the brass adjustment pot, just to avoid problems down the road if they aren't there already...
Yes I sell these parts. The parts site is constantly getting updated with parts, so there are some things that aren't on there yet :sad:

The voltage regulator is here: https://shop.gentekpower.com/products/g ... ulator-avr
The DPE breaker for this unit is here: https://shop.gentekpower.com/products/g ... aker-3-amp
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Post Reply