3 ms·

A few years ago my children's hamster escaped. We couldn't find him for days. I figured he had made it outside somehow cause we didn't see him or hear him or

by JackFr 7y ago

A few years ago my children's hamster escaped. We couldn't find him for days. I figured he had made it outside somehow cause we didn't see him or hear him or see any droppings. After about 4 days though, there was an off smell in the kitchen. We tore everything apart, emptied every cabinet, pulled the stove out from the wall, moved the refrigerator, etc. and still could not find him (or any evidence of him.) We scrub everything and out it all back. But the next day, smell is still there. Then it occurs to me that the refrigerator back panel has holes to vent the fan. I shine a flashlight and see some fur. Bingo. I take the back off the fridge, but I still can't reach him. At this point its not clear to me what's killed him. I get some tongs to grab him but I see he's stuck. I wiggle his body free and pull him out, and immediately the fan starts arts spinning full speed and I nearly retch. The point of the story is 1) R.I.P. Jordan the hamster, and 2) The condenser fan was basically held in place for 4 days without burning out - very impressive as far as I'm concerned. (This was a very old refrigerator BTW)

userbinator 7y ago
The condenser fan was basically held in place for 4 days without burning out As the video mentions, this is a deliberate design decision for safety and robustness --- the motor is designed to survive being stalled indefinitely without damage. It's known as "impedance protected", because the impedance of the winding is such that it will never draw enough power to burn itself out. The downside is low starting torque, which is why they're only used for things like fans. (I was referring to the older shaded-pole motor; the newer one might blow the fuse instead, which is still OK from the safety standpoint but definitely not robustness.)

3 ms·

A few years ago my children's hamster escaped. We couldn't find him for days. I figured he had made it outside somehow cause we didn't see him or hear him or

by JackFr 7y ago

userbinator 7y ago
The condenser fan was basically held in place for 4 days without burning out As the video mentions, this is a deliberate design decision for safety and robustness --- the motor is designed to survive being stalled indefinitely without damage. It's known as "impedance protected", because the impedance of the winding is such that it will never draw enough power to burn itself out. The downside is low starting torque, which is why they're only used for things like fans. (I was referring to the older shaded-pole motor; the newer one might blow the fuse instead, which is still OK from the safety standpoint but definitely not robustness.)