Standby generator issues you see in cold weather

[Alan]

Now that we are in the second week of December, the temps are dropping and standby generators across the country are starting to show their winter personality. Some fire up perfectly and others act like they are still asleep under a blanket.

What is the most common issue you see when the cold hits? This could really help members who have not done their pre winter checks yet and might be one weird sound away from a headache.

 

[ZenithDragon]

I’ve noticed fuel related issues pop up more in the cold. Lines get sluggish and starts aren’t as clean as warmer months. Most homeowners don’t think about it until the generator acts up during an outage. Winter is not the time to find out something was borderline.

 

[PGB1]

Zenith Dragon made a great point about fuel. Diesel units are notorious for wax clogs when the temperature drops.

Most Frequent Call I Get When The Temp Drops:
Stuck transfer switches tend to appear by the many after it has been warm, then suddenly gets cold. (About the same time that power lines fall from ice & the building needs the generator.)

Moisture condenses and the slides & guides get ice on them, preventing the contactor from engaging. At worst, it moves close enough for arcing, thus burning the contact points. I find this arcing most often on higher voltage switches. (13,200 vac is commonly used in this area.)

For small, 1220/208 or 230-Delta units, such as those found in medical buildings, often a good hit with a fist frees the contactor. I would imagine that this is common on house units, too.

It works backwards, too. I had a recent call from a building's facility maintenance stating that the neighboring buildings had power back for more than a week, but the facilities's generator was still operating. The utility verified power was restored to that building. The transfer switch was stuck closed, keeping the generator operating. (I'd hate to see their natural gas bill for that month!)

Contactors can get stuck all year. Since the scheduled exercise for generators doesn't move the contactor, it's wise to occasionally force it to transfer by opening the utility side disconnect, simulating a power failure.