AboutWill Expertise Three phase electic motors, controls and related problems or failures, three phase motor installation issues, performance issues, connections, data and duty cycle information. All other electic motors. Specialty motors, repair concerns, performance concerns, obsolete motors and solutions. Other specialty equipment issues. Lost nameplate data and identification, lost connection data.
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Experience 30 plus years in the electrical motor and apparatus repair industry. VP level management of repair facilities, current owner of my own specialty repair and consulting firm.
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Expert: Will Date: 6/29/2008 Subject: GE fractional HP - centrifugal switch problem
Question Motor is Model 7J401AS, Frame 31, Type KH
Issue: motor will not leave "start" winding and therefore quickly overheats. No wiring diagram for motor.
Has 3 terminals; AC Line connected to yellow and heavier black that in turn goes to centrufigal switch contact
AC line connected to orange and blue
Unused, terminal connected to red.
Problem is suspected to be operation of centrifugal switch, motor was dissassembled and may have been put together incorrectly. There is a plastic disc that does not seem to slide in and out correctly to open the start circuit. There is no obvious reason why it is not working, it slides, the springs and rotor mechanism are OK. I need a mechanical view showing how it should go together along with proper wiring for single phase 115 VAC connections.
Much obliged. Allan
Answer Allan,
GE fractional frame motors were sold to Marathon which was sold to Baldor who was sold to,,,,,,,,
anyway, even a service shop would not have drawings as these motors are considered throw away.
You might find some of these forums where someone just happened to get one from somewhere or made one up, but in these days of pitch everything, it is too costly to store and file repair procedures and drawings for anything but much larger apparatus, and even then that information is normally proprietary.
Google the hell out of the words GE motor fractional frame 31, and other boolean searches and maybe something will show up.
There are a couple things you can try, first the spool or centrifugal switch, has springs that at a certain force created at a certain rpm are overcome, and the switch or spool drops away from the stationary switch arm, and opens the start circuit.
Sounds like you have the problem narrowed down, but a drawing is not likely.
The switch or spool if worn, will be really lose on the shaft, and if so, it is not repairable. If the springs have lost their strength, that will do it also. There are not to many ways these go together, so if it moves up and down, and you can take the end bell, with stationary switch, and partially assemble the motor, and visually confirm the spool is letting the switch arm move and open, it may be a shorted winding, down inside and not visible.
But many times it is an adjustment of the stationary, including very carefully bending the arm so it either rides on the spool with more or less force and gives clearance to open.
Some motors you can see this very easily, others you cannot, and by the model I cannot tell.
If the motor is assembled can you put a [no power to it!] wood tongue depressor or something in through a vent and press down on the spool?
If so, put an ohm meter where the power leads go, short across the cap, if it has one, and the ohm reading should change when the spool is manually depressed.
It is not a real easy task but can be done, depending on the motor.
Next, there are amperage or voltage relays, that can be used to replace both the stationary, and centrifugal switches.
You can go to Jenkins Electic motors and buy a kit to install a relay, and do away with the mechanical parts.
Or if the motor is not real special, and by that I mean it mounts some special way, threaded shaft[s], a replacement motor might be a much easier route.
The model tells me nothing, as GE no longer has anything, out there for fractional.
Or go to ebay and search for a used GE motor with the same frame, and either use it, or rob parts, or copy the assembly.
If I get lucky and find a diagram I will send it to you, but I see nothing so far.Check below:
