Electric GE mantle clock runs fast

[Ed O'Brien]

I disassembled and cleaned a mantle clock, lubricated it and set it up on my test stand. Overnight it gained about five minutes. Only thing missing are the hour hand and the Westminster chime hammers. The rotor is totally quiet and clock runs smoothly. Any suggestions as to why it would run fast, or means to slow it?

Ed O'Brien
Fixoclock

 

[davefr]

First of all, it's impossible for a synchronous Telechron motor to run fast when it's connected to the same frequency source as it's geared for. (ie 60 Hz in North America). Here are the reasons the clock may appear to run fast:

1. Loose hands or hands that hit each other as they pass each other. (very common)
2. A badly worn movement where gears slip. (not very common)
3. Using a motor geared for a lower frequency then the power source. (sometimes this happens when using a 50 Hz motor on a 60 Hz line but that would be a consistent gain of 12 minutes per hour)
4. Your utility isn't providing precise 60 Hz power (not at all common)