Ac motor!! 3phase!!! Help

[mscountry]

I have a ezgo sport edition cart and need some input/help. 48vc, batteries are hot and hold a load good. I can walk faster than the cart runs. The 3 leads going to the motor show 48vdc until I push down the accelerator and they then drop to 24vdc. Is this normal? The key switch has "off", "reverse", "neutral" and "forward" like the RXV. Can someone point me in the right direction?

[BobBoyce]

Originally Posted by mscountry

I have a ezgo sport edition cart and need some input/help. 48vc, batteries are hot and hold a load good. I can walk faster than the cart runs. The 3 leads going to the motor show 48vdc until I push down the accelerator and they then drop to 24vdc. Is this normal? The key switch has "off", "reverse", "neutral" and "forward" like the RXV. Can someone point me in the right direction?

It sounds like you may have an issue with the motor speed sensor. Open the plastic cover with the run/tow switch over the controller, and tell us the color of the metal over the resistor behind the controller. Black or silver colored?

[mscountry]

Bob, The housing and coils are silver colored. I pulled he plug off the speed sensor and it had been ripped loose and taped back together. Removed the tape and butt spliced the broken wire, still no change. The batts are 5yrs old and the lowest battery shows 10.5 vdc under a load tester.

[BobBoyce]

Originally Posted by mscountry

Bob, The housing and coils are silver colored. I pulled he plug off the speed sensor and it had been ripped loose and taped back together. Removed the tape and butt spliced the broken wire, still no change. The batts are 5yrs old and the lowest battery shows 10.5 vdc under a load tester.

Ok, that tells us that you likely have the Danaher controller. At 5 yrs old, the batteries are likely near end of life. The motor speed sensor may have been damaged when the wiring was damaged. You might have the bearing type of motor speed sensor instead of easy to replace later model unit.

[mscountry]

Bob, Yes it must be a bearing sensor with a 2 prong connection at the top of the motor. I there any way to test the resistor coils? I saw on another post about unplugging the cable from the "B" connection on the controller. Did that and still no change.

[BobBoyce]

Originally Posted by mscountry

Bob, Yes it must be a bearing sensor with a 2 prong connection at the top of the motor. I there any way to test the resistor coils? I saw on another post about unplugging the cable from the "B" connection on the controller. Did that and still no change.

The motor temperature sensor would have 2 wires. The motor speed sensor would have 4 wires. +5V, negative, and 2 signal leads. The motor speed sensor/bearing can be changed, but it must be done carefully to prevent damage to the new sensor.

The resistor on the Danaher controlled RXVs is switched by the resistor control module. There is a harness connector from the controller to the resistor control module.

[mscountry]

Thank You Bob Boyce, Do you think the sensor could be bad or would the wire on the temp sensor being bad cause overheating? Who on BGW would carry the speed sensor kit?

[cgtech]

Testing the temp sensor is pretty easy. It should read between 400-1200 ohms if I recall correctly. A failed sensor always seems to read as a dead short (0 ohms), or open (no reading at all).

[BobBoyce]

Originally Posted by mscountry

Thank You Bob Boyce, Do you think the sensor could be bad or would the wire on the temp sensor being bad cause overheating? Who on BGW would carry the speed sensor kit?

A bad temperature sensor reading can cause cutback in operation if the controller reads it as an overheat. I suggest you fix the connection because the sensor itself is imbedded in a motor winding and cannot be replaced.

[mscountry]

I fixed the connection and still no go. going to check the ohms on the lead.