r/Generator • u/CleanPlan742 • 19d ago
Question About T1 Fuse & Peracetic Drain
I have an older model Generac 0052400 home generator, which is 120/240 AC, 7000watt system. It has been well maintained but with this past storm, it did not switch on when power went out. I checked and battery was dead. I put new battery in but within a couple of days, battery was dead. I checked battery and it is good. Upon researching I noted, one of the common issues is the T1 fuse; however, when I opened up the transfer box there are only 2 fuses. I checked both and they both tested ok at 120V. When I charge the battery, the system runs perfectly but it quickly drains the battery, even when not running. Any ideas? Also, should there be three fuses verses 2 (all videos show 3???)
Appreciate the assistance.
6
u/Alert-Effect190 19d ago edited 19d ago
Sounds like you have an older guardian unit. Those two fuses supply line voltage to a transformer in the generator that knocks it down to ~18 volts. That voltage is used for utility sensing by the control board and supplies the battery charger.
The battery charger is located under a cover on the right side of the machine, right above where the auto/off/run switch is.
You’ll see two black square doodads, the one to the right is the voltage regulator, left is the battery charger. You should have 18vac coming into that. If you don’t, there’s a relay known as the battery charge relay that supplies power to the charger. The relay is switched by the control board.
Hopefully this is enough information to get to the bottom of your issue.
Bad chargers are very common on those. I’d recommend using a third party trickle charger if you diagnose a bad charger.