kjoiner
Mechanical
- Oct 31, 2002
- 461
Hello,
We are revising a control panel for a machine to work with 110VAC or 220VAC. The machine plugs into a wall outlet. The panel uses 3 DIN mount switching power supplies. In the US, we can use single switches or breakers to cut power to each power supply because the hot and neutral are polarized. We can be sure the hot is switched.
In European applications, some plugs like the 2 prong Schuko can be installed either way. This has the effect of reversing the hot and neutral with the switch only breaking the neutral.
To cut power to the entire machine, we have a 2 pole key switch that can break both the hot and neutral regardless of orientation.
It seems we will need some type of 2 pole switch for each power supply to ensure we are cutting both. I have 2 issue with that. The first is cost and the second is safety.
A brute force method is to use an IEC power strip with cords and plugs to each power supply. Unplugging a power supply is a certainty that both lines will be disconnected. Our space is tight but this is still feasible.
What I want to know is how are industrial control panels that are plugged in rather than hard wired set up to address this? I struggle with issue since European safety standards are so strict yet polarity issues are allowed.
We are revising a control panel for a machine to work with 110VAC or 220VAC. The machine plugs into a wall outlet. The panel uses 3 DIN mount switching power supplies. In the US, we can use single switches or breakers to cut power to each power supply because the hot and neutral are polarized. We can be sure the hot is switched.
In European applications, some plugs like the 2 prong Schuko can be installed either way. This has the effect of reversing the hot and neutral with the switch only breaking the neutral.
To cut power to the entire machine, we have a 2 pole key switch that can break both the hot and neutral regardless of orientation.
It seems we will need some type of 2 pole switch for each power supply to ensure we are cutting both. I have 2 issue with that. The first is cost and the second is safety.
A brute force method is to use an IEC power strip with cords and plugs to each power supply. Unplugging a power supply is a certainty that both lines will be disconnected. Our space is tight but this is still feasible.
What I want to know is how are industrial control panels that are plugged in rather than hard wired set up to address this? I struggle with issue since European safety standards are so strict yet polarity issues are allowed.