Honeywell Replacement

[QuadDude]

I have a customer who is wanting to replace their Honeywell UD3200 and I am trying to find information on Slidewire Feedback. Is this just a 4-20mA signal.
The Honeywell is connected to a Barber Coleman EA57 or EA71.
Any help here would be greatly appreciated.

 

[danw2]

The UDC does a great job of position proportional control. Why replace it?

Do you need to convert the motor to accept a 4-20mA output? The UDC 3200 can be field retrofit with an "auxiliary output" board, which can be configured as a control output, if necessary.

If the motor's slidewire is broken, the UDC has a back-up method of controlling motor actuators, called 3 position step control, a form of open loop actuator control based on motor timing, rather than the closed loop control provided by slide wire feedback.

In answer to your question, is slide wire feedback just 4-20mA signal, the answer is no. Position Proportional and 4-20mA are both techniques to control a motor's position, but any given motor either has a converter built into it to convert the 4-20mA to the appropriate drive signals, or it doesn't.

Position Proportional is inherently proportional control (like 4-20mA is), with a percentage output that corresponds to the rotational position of the motor shaft; 0-100% output corresponds to 0-90° rotation.

The concept of position proportional is that the controller reads the slidewire's (wired with 3 wires back to the controller) resistance feedback signal which determines the position of the motor shaft, which then tells the controller whether its calculated percentage output is the same as the position of the motor shaft. If the % output does not equal the motor shaft position, the controller will drive the motor in the appropriate direction to achieve its calculated proportional output. Position Proportional has lost favor to 4-20mA over the years because
- Position proportional needs 6 wires between the controller and motor, 4-20mA only 2 wires
- the slidewire input card on the controller adds cost to position proportional.

The BC actuator motor has a 100 ohm or 135ohm slidewire in it that is mechanically driven so it provides an indication of the position of the motor's output shaft, either 0-90° or 0-180° (depending on motor)

The actuator motor has 2 windings, connected to a common. When power is applied to one winding, the motor rotates clockwise (CW). When power is applied to the other winding, the motor rotates counter clockwise (CCW). The motor runs a gear train. The higher the gear ratio, the slower the rotation rate, but the greater the resolution of the output position. There is no way without a converter to get 4-20mA to drive the motor, which needs power switched to its windings.

There are commercial converter modules that convert a 4-20mA control signal to two on-off outputs that can drive a motor CW/CCW. The converters all need slidewire feedback, in addition to a 4-20mA control signal to operate properly.

- Honeywell's converter was the R7295A. Don't know if it's still available.

- API's converter is model API 3200G, a unit that mounts into an 11 pin socket that can mount on a DIN rail. 4-20mA & resistance input, SPDT output with 'neutral' position. This was available a year ago.

http://www.apicb.com

- Barber Colman's 658A mounted on the side of the actuator, the 658B had a base flange for mounting. I don't know if these are still available

To implement the 3PSTEP conversion,
1) change the algorithm CONT ALG setting to 3PSTEP (three position step control),
2) Under OUTPUT, confirm that OUT ALG = POSITON
3) Under OUTPUT, enter the motor time, stop-to-stop under MOTOR TI

There's a tech note on checking wiring and configuration for the UDC 3300, (same for practical purposes as the 3200) at

http://content.honeywell.com/ipc/faq/pdf/937601.pdf

If I recall properly, the UDC controller will drive the motor full scale open, then back again on the first power up to establish the limits and the actual motor timing, if one doesn't do the calibration routine under "calib" .

If you add the aux out card to get a 4-20mA control signal, be sure to "calibrate" it (run output into milliamp meter, check & tweak 4.0mA and 20.0mA), otherwise the UDC won't recognize the card.

Dan

 

[joecontrol]

I have used the barber coleman 658 converters many many times and they work very well.

You will still need the slidwire to work to let the op amp in the converter know the actual position the motor is in.

Good luck,Joe

I am sure the local honeywell rep would build you a model # for the new udc controller you would need as a direct replacement.