Home Forums General Discussion Technical Questions Very old dover traction with damping motor?

Hi, Have a old dover on service that has drove my nuts! The unit has damping motor that is running in only the dn dir,but when going up the unit runs slow speed and the damping motor does not spin. The unit has a 16/15 relay were most compsites have a 14/15 relay. I know there is a issue with the damping motor.The damping motor was rewound and I think this was wound wrong. I can email prints if someone can help,Thanks

Make certain the dampening motor is correct-this will affect all loop circuit current. If the dampening motor was rewound was it because of other issues? Make sure you are getting the high speed relays in-in both directions and they are making up good. Check to see that your motor field is decaying away from full field when you go in the up direction. Does this car run the same speed on inspection in both directions (+ or - 10%)? The dampening motor will not move if there is not enough loop circuit voltage-generator output. Check all your loop circuit connections, brushes, and contacts.

The damping motor was rewound due too armature shorted. One question i have is the configuration of the damping motor. When I received motor back f1 and s1 were tied together, this did not seem right as that prints show damp motor field and armature in diff circuts. My thinking is that motor is mis-wired.

I dont have the Dover with the damp motor print-I have mostly Compumatic stuff. Most manufacturers put the field and armature in seperate circuits or isolated from each other by contacts. If your damp motor is not correct it would cause all kinds of issues. Once the damp motor is configured correctly be sure to add the fly wheel that was on the motor, if it had one-this would create a slower accel and decel slope. The damp motor armature is a direct short when voltage is first applied, effectively "shunting" voltage away from the hoist motor armature. As the damp motor picks up speed it increases in resistance there by allowing more voltage to the hoist motor armature. This gives you a fairly nice accel rate-depending on the weight of the damp motor fly wheel or lack there of. The damp motor field should always be constant-never changing-that is if its designed as Im remebering. The armature of the damp motor will be in series with some variable resistors and some accel contacts along with your "Up" and "Down" potential contacts. If your print does not show the damp motor field connected to the armature then I would deffenitly fix that first.

Hey mbskin, email me a copy of the circuit, I think i can help email [email protected]
im with e311 on this one as far as the motor wiring is concerned, s1 is usually a series field connection and is wired in "series" with the damping motor armature. You should have 2 shunt field connections and 2 motor field connections, along with the 2 motor armature connections. if your series field is not wired correctly, it is possible that it could "buck", or negate the shunt fields magnetic field and cause the armature not to spin. I have never seen a dover with a damping motor armature in the loop circuit, it is usually in the generator field circuit, and dampens the voltage input across the generator field itself thereby giving a nice acceleration rate. I would like to see the print E311 is correct in his assessment of the circuit, but I dont think the damping motor is in the loop circuit, if it is it would be a new one to me, and I would once again say to myself there is always something new to learn in the elevator business.

e311,I have never seen a dover with damp motor till now. I have worked on dover equip for over 20 yrs LOL. What is strange is the 16 relay instead of 14. This seems to be a timer as it controls the pick of 15. I was told this is one of the very first traction dover did. Scott prints on the way,e311 I can send too if u like ,Thanks

The print I was referring to was a Meco or GAL...I was thinking that the Dover might be pretty similar. The only Dover I have seen with a damp motor was about 12 years ago-first and last Ive seen.

thanks for the print, I dont know if you have resolved your problem yet, but if not you can try to isolate the problem by blocking out the n/o contacts 3/7 and 4/8 on the 10A1 relay. If the car will go full speed in both directions with these contacts blocked out, then you know your problem is in the damping circuit. you could then disconnect one of the damping motor armature wires from the circuit and again run the car and see if full speed in both directions is obtainable. If it does then you know the damping motor is causing problem, if it still does not work with damping motor armature out of the circuit, it could be that one of those capacitors in the circuit is shorted. after looking at the print the field wires should not be connected to the armature wires, it should be connected just as the print shows, I was wrong with my previous reply regarding the motor connections. there should only be 2 motor field wires and 2 wires for the motor armature, you may have 2 wires for the series field also. if you do, then they need to be wired in series with the motor armature. let me know how many leads you have coming out of damping motor