milldrone
Member
Greetings,
At the facility I work for we have five PF700S's. Four of them have given very good service, with no problems. All five were originally set up with 24V DC inputs on DI 1-3 and 115V AC inputs on DI 4-6. All five drives use the same control scheme. DI 1 (24V) is the start, DI 2 (24V) is the stop, DI 3 (24V) is connected to a hard selector switch, DI 4 (115V) is connected to another hard selector switch, DI 5 (115V) is connected to a "reset PB". Lastly DI 6 (115V) is connected to a output from a E stop relay. Inputs DI 3, DI 4, and DI 5 are not controlling the drive directly but are used as remote I/O, the bits are seen by the PLC over controlnet. We are using DI 6 as the hardware enable, so the HW enable jumper has been positioned for this function.
The machine center in question has had several episodes of DI 6 not functioning. In each instance of DI 6 not working there was 115V at pin 16 (this is the input for DI 6). Wiring has been checked several times, nothing abnormal was ever found. The first failure was 18 months after commissioning, the main control board cassette was changed (the dip switches were set for 115V and the HW jumper positioned) and production resumed. The second failure happened 12 months after the control cassette was changed. This time the EE wanted to change the entire drive to eliminate any possible problems associated with parts other than the main control cassette. Again the dip switches were set for 115V and the HW jumper was positioned. Another failure happened 6 months later and the main control cassette was changed again. Again the dip switches were set for 115V and the HW jumper was positioned.
The EE wanted to take some preventive measures, so he commissioned a work order to change the 115V AC controls to 24V DC controls. The work was done and the dip switches were set for 24V but the sparky missed one wire, you guessed it, he left the common for inputs DI 4-6 attached to the neutral. Another main control cassette was swapped in (while the neutral was still connected to the common). This cassette did not function as expected (the wrong drive outputs were energized, more to follow on this cassette) so the original was reinserted. The trouble was diagnosed and the wire switched to the internal voltage pin. Another cassette from a working drive was swapped in (with proper dip switch and jumper settings). The strange thing was that this cassette also failed to function on DI 6, so not having any spares we enabled the software enable jumper and connected the Estop to DI 5 (after some changes in logic).
I set up our spare drive on the bench and tested the "defective" cassettes on 24V and 115V. I found that the cassette that had been in place for the requested change from 115V to 24V did not function on 24V but still functioned on 115V (DI 6). The cassette that produced unexpected results still functioned on 24V and 115V (DI 6). I also found why it was producing unexpected results. The HIM was never loaded to the device and was at factory parameters. I also had to flash the cassette to a version the rest of the drives were also using so there would not be any controlnet issues.
Has anyone seen input DI 6 fail before?
At the facility I work for we have five PF700S's. Four of them have given very good service, with no problems. All five were originally set up with 24V DC inputs on DI 1-3 and 115V AC inputs on DI 4-6. All five drives use the same control scheme. DI 1 (24V) is the start, DI 2 (24V) is the stop, DI 3 (24V) is connected to a hard selector switch, DI 4 (115V) is connected to another hard selector switch, DI 5 (115V) is connected to a "reset PB". Lastly DI 6 (115V) is connected to a output from a E stop relay. Inputs DI 3, DI 4, and DI 5 are not controlling the drive directly but are used as remote I/O, the bits are seen by the PLC over controlnet. We are using DI 6 as the hardware enable, so the HW enable jumper has been positioned for this function.
The machine center in question has had several episodes of DI 6 not functioning. In each instance of DI 6 not working there was 115V at pin 16 (this is the input for DI 6). Wiring has been checked several times, nothing abnormal was ever found. The first failure was 18 months after commissioning, the main control board cassette was changed (the dip switches were set for 115V and the HW jumper positioned) and production resumed. The second failure happened 12 months after the control cassette was changed. This time the EE wanted to change the entire drive to eliminate any possible problems associated with parts other than the main control cassette. Again the dip switches were set for 115V and the HW jumper was positioned. Another failure happened 6 months later and the main control cassette was changed again. Again the dip switches were set for 115V and the HW jumper was positioned.
The EE wanted to take some preventive measures, so he commissioned a work order to change the 115V AC controls to 24V DC controls. The work was done and the dip switches were set for 24V but the sparky missed one wire, you guessed it, he left the common for inputs DI 4-6 attached to the neutral. Another main control cassette was swapped in (while the neutral was still connected to the common). This cassette did not function as expected (the wrong drive outputs were energized, more to follow on this cassette) so the original was reinserted. The trouble was diagnosed and the wire switched to the internal voltage pin. Another cassette from a working drive was swapped in (with proper dip switch and jumper settings). The strange thing was that this cassette also failed to function on DI 6, so not having any spares we enabled the software enable jumper and connected the Estop to DI 5 (after some changes in logic).
I set up our spare drive on the bench and tested the "defective" cassettes on 24V and 115V. I found that the cassette that had been in place for the requested change from 115V to 24V did not function on 24V but still functioned on 115V (DI 6). The cassette that produced unexpected results still functioned on 24V and 115V (DI 6). I also found why it was producing unexpected results. The HIM was never loaded to the device and was at factory parameters. I also had to flash the cassette to a version the rest of the drives were also using so there would not be any controlnet issues.
Has anyone seen input DI 6 fail before?
