First cold outage changed how my generator behaved

[PennyStar]

We had our first cold outage of the season last night and my generator did its job, but I noticed it didn’t behave exactly the same as it does during warmer months. Everything powered up fine, but the startup and transfer felt just a little different than what I’m used to.

Nothing tripped and there were no alarms, so I’m not worried. It just caught my attention because it’s usually very predictable. Cold weather was the only real difference compared to past outages.

Have you noticed generators acting slightly differently during the first cold outage of the season, even when everything is working normally?

 

[WalterTensei]

I pay extra attention during the first cold outage too. When the house is depending on it, any change stands out. From what I’ve seen, colder temps can make the startup sequence feel different without meaning anything is wrong. As long as it carries the load smoothly, I don’t stress it.

 

[Alan]

That’s a good catch. When you say it felt different, was it longer crank time, a rougher first few seconds, or the transfer taking longer than usual?

 

[PGB1]

Hello PennyStar,
Welcome to the forum!

The odd noises could be tight bearings from cold. Was it kind of "groany" or screechy? Does the engine sound normal again quickly? This is common in small engines because it is easy to hear.

If it takes more than a minute to sound normal, if could be Piston Slap. (Sounds almost like a diesel engine) That's common in small engines in cold. (GM 5.3 and 6.0 liter Trucks for many years, too). When the rings get warm, they swell and the slap will go away.

Also be sure to check the owner's manual for the engine to ensure you are using the correct oil for the temperature. Some oils, even multi-viscosity, are too thick in winter for some small engines and will delay lubrication, causing odd sounds until the engine gets a little warm.

The transfer switch also could have been a little stuck from condensation freezing on the slides of the contactor. That's common in cold & often due to hoar frost on the contactor(s)' slides. You may even hear a chatter for a second or two while the slide(s) break free,

If it ever is so stuck that it won't move, a gentle tap (machine off) on the face with a small, rubber mallet will often free it. Gentle Tap!
It could be stuck from dirt, plastic shaving or insect debris also. The contactor(s) in the transfer switch don't move during weekly self-testing so sometimes they hang up when needed. Tricking it into transferring periodically will keep it clean and ready.

Hope This Helps,
Paul

 

[Maya_Mahabala]

I’ve seen it depend a lot on what it runs on. Gasoline, propane, natural gas, they all seem to have their own cold weather quirks. Even when it’s working fine, the first cold start can sound different and the unit can take a bit longer to settle. If yours is usually super predictable, the cold alone might explain it. What fuel are you using and how cold did it get where you are?