Home Forums General Discussion Technical Questions Old Dover Turnbull. Brake Servo

Hi Folks!
I am having any issues with a Dover Turnbull Brake Servo in the down direction only. Only at the top 3 floors of a 10 stop overhead traction. It is a levelling problem. The car stops 8-10" high every time. I recently replaced the brakes and also serviced all the relays in that circuit. Does anyone have any suggestions? Is it a brake issue? or a power issue as the car is descending and trying to pull the counterweight up from the lower floors? From the halfway point down the floor levels are good. This is a non-generator job. Any Tips would be greatly appreciated.

Need more info. Are you slowing down and then dropping the Brake circuit when you hit Leveling? Are the Rails tighter at the top? Are the Counterweight rails too tight at the Bottom? You can clamp on an Analog Amp Meter and see if you are pulling more Amps. Is this an AC OR a DC Motor? If it is DC you may need to strengthen your Motor Field. What happens when you put a full load on, does the problem change? Need more info.

I am slowing down and dropping the brake circuit yes. It is an AC Motor. We have not done a full load test at this point. I did notice that we loose the "D" contactor and the "U" contactor picks up. On our next visit we will check with an Analog Amp Meter. I did notice that one of the rings on the end of the motor were the brushes are appears to be badly burnt /worn different that the others. No changes have been made to the DBG on the rails.

you may have a travel cord problem. You need to find out why you are dropping the D contactor. You need to maintain direction through out the run. Does the relay supply voltage stay steady when you pull more Amps during slow down? Use analog meters which react quicker than digital ones, and find out what causes D to drop.

Thank You.