Reduce voltage to DC Motor
Reduce voltage to DC Motor
(OP)
I am helping to restore a 1950 Diesel-Electric Locomotive. It has an oscillating headlight. The motor for the headlight is nameplate rated 30 VDC. The locomotive electrical system is 64 VDC. The motor appears to be shunt connected. Before I came on the scene, someone tore the unit apart with no apparent interest in ever putting it back together. There are two wire wound resistors that were somehow connected to the motor. One resistor is 100 ohms fixed. The other has a slider so it can be adjusted to between 0 - 100 ohms. The adjustable resistor is a larger wattage than the fixed. The motor is definately a 30 V motor. I hooked up a dc power supply, and the motor runs great at 30 V. Boost the voltage to 60 and motor smells like there is arcing at the brushes and the whole motor gets hot. Somehow these resistors hook into the motor to make it work on the higher supply voltage, but I don't know how. Can anyone help?





RE: Reduce voltage to DC Motor
http://www.trainweb.org/gyra/warnlts.htm
http://www.trainweb.org/
etc. for more info
Does that light or motor have any nameplate?
RE: Reduce voltage to DC Motor
http://www.thomasregister.com
and type Locomotives: Diesel-Electric under Product or Service, which will return 20 companies to approach to for information or a spare part
RE: Reduce voltage to DC Motor
The smaller, non-adjustable resistor was most likely installed in series with the shunt field and its purpose is similar; that is, to drop the voltage to the appropriate value for the shunt field.
RE: Reduce voltage to DC Motor
The load current of the motor at rated voltage and actual wattage of the resistors would be needed to determine exactly how to connect the system. The voltage at the junction will change depending on the motor load.