Soggy Canuck
Lifetime Supporting Member
I have inherited another mangled machine upgrade (fifth one in two years). This one is particularly appalling.
The machine is a compactor-baler combination. Judging from the original components left in the MCC it was built in the late 70's early 80's. The control relays have all been pulled and replaced with an IDEC PLC. The outputs from the PLC have been interposed with a combination of SSR's and ice cube relays. The inputs have been interposed with ice cube relays.
The wiring has all been replaced with 18ga solid wire 30volt rated on 110Vac circuits. Relays have been taped into position on the finger tray and when they ran out of room, left lying loose in the bottom of the MCC. There is not one wire marker anywhere.
What safeties that have been retained have been wired back as discrete inputs to the PLC (Definitely NOT a safety rated PLC). The E-Stops (five of them) are each pulled into the PLC as individual N/O devices, with interposing relays no less.
Hydraulic overpressure saftey switches, access gate guard switches, and pull rope E-stop switches have been abandoned.
There is no MCR relay, and no dedicated safety circuit of any kind.
As of this post I have not been able to access the PLC program. My IDEC software is to old. I am not looking forward to seeing if the code matches the wiring.
This is the worst example of this type of workmanship I have run across in recent memory, but by no means is it an isolated incident.
As someone who takes pride in supplying professional automation service, this mickey mouse approach to machine upgrade really makes my blood boil.
Whats the worst project you have had to rescue from the "I have a laptop so I can fix anything brigade"?
The machine is a compactor-baler combination. Judging from the original components left in the MCC it was built in the late 70's early 80's. The control relays have all been pulled and replaced with an IDEC PLC. The outputs from the PLC have been interposed with a combination of SSR's and ice cube relays. The inputs have been interposed with ice cube relays.
The wiring has all been replaced with 18ga solid wire 30volt rated on 110Vac circuits. Relays have been taped into position on the finger tray and when they ran out of room, left lying loose in the bottom of the MCC. There is not one wire marker anywhere.
What safeties that have been retained have been wired back as discrete inputs to the PLC (Definitely NOT a safety rated PLC). The E-Stops (five of them) are each pulled into the PLC as individual N/O devices, with interposing relays no less.
Hydraulic overpressure saftey switches, access gate guard switches, and pull rope E-stop switches have been abandoned.
There is no MCR relay, and no dedicated safety circuit of any kind.
As of this post I have not been able to access the PLC program. My IDEC software is to old. I am not looking forward to seeing if the code matches the wiring.
This is the worst example of this type of workmanship I have run across in recent memory, but by no means is it an isolated incident.
As someone who takes pride in supplying professional automation service, this mickey mouse approach to machine upgrade really makes my blood boil.
Whats the worst project you have had to rescue from the "I have a laptop so I can fix anything brigade"?