Swamp_Sparky
Member
- Location
- Austin, TX, USA
I recently interviewed for a position with a local control panel builder, and during the interview process, the manager presented me with a set of drawings for a project currently under construction, with the intent of testing my knowledge of the components, etc.
One thing that jumped out at me while I was reviewing the drawing was a consistent use of contactors in the panel with a mix of voltages on them, i.e., the main contactor used both a 208v input on 2 connectors and the pos side of a 24vdc power supply through the other. Other contactors used 110v along with 24vdc in them. The 24v was also being used throughout the system as control power. Wiring was clearly identified, however I felt that this could be a serious personnel/equipment safety issue once the product is in the field. I can't find any specific prohibition against this practice, and was hoping someone could point me to a specific instruction either allowing or prohibiting this.
One thing that jumped out at me while I was reviewing the drawing was a consistent use of contactors in the panel with a mix of voltages on them, i.e., the main contactor used both a 208v input on 2 connectors and the pos side of a 24vdc power supply through the other. Other contactors used 110v along with 24vdc in them. The 24v was also being used throughout the system as control power. Wiring was clearly identified, however I felt that this could be a serious personnel/equipment safety issue once the product is in the field. I can't find any specific prohibition against this practice, and was hoping someone could point me to a specific instruction either allowing or prohibiting this.
