WHAT DOES AN ORANGE WIRE DO IN A CONTROL PANEL?Why would we want to keep things on when we’ve turned the power off.
In a previous article, we covered the basics of an Electrical Control Panel. Now we’re going to take a closer look at some of the other important components that go towards making up the panel.
Now, this article is a little different, as we’re going to look at something that features everywhere inside the control panel but holds a special function that separates it from the rest of its brothers.
We are going to be looking at the orange wire inside of the panel, WHY it is special, and what we use it for.
Now you may be asking how can an orange wire be special? It does not exactly have superpowers, but inside our panel, it holds a secret that we’re going to find out!
Within the panel, we have a number or orange-colored wires.
You may wonder what these are for, as we’ve already heard of the blue and white wires connected to the PLC.
Well, what these wires are for is to give power to devices when the main switch or panel isolator is in the OFF position.
“Why would we want to keep things on when we’ve turned the power off?” I hear you ask! “Isn’t that dangerous?” Well to put it simply, NO!
If we try to understand the different colored wires in a panel, this will help us to understand why those that are colored orange are suitable to work even when the main switch is off.
The colors of wires in panels are required by law to follow the machine safety standard EN 60204-1. This is so that there are consistency and safety.
In Power Circuits, AC and DC, we have this color-coding;
AC Phase will be BLACK, AC Neutral will be LIGHT BLUE, DC+ will be BLACK and Earth will be GREEN YELLOW.
3-phase Labeling System
In Control Circuits, AC and DC, we have this color-coding;
AC live will be RED, AC Neutral via transformer will be RED, AC Neutral (mains) will be LIGHT BLUE and DC+ will be BLUE.
Interlocks and circuits supplied from remote panels will be ORANGE; in this case, not the one we’re after!
Finally, Earth will be GREEN YELLOW.
Panel services are 240VAC supplies for panel internal lighting, programming console socket outlet, internal heating and cooling, CPUs (memory backup purposes), etc.
These are excepted circuits as defined in EN60204-1 and as such are not disconnected by the main panel isolator but by a separate isolator mounted inside the panel and designated maintained supply.
The color-coding for multicore cables is like this;
The sheath will be ORANGE, AC live cores will be ORANGE, AC neutral cores will be ORANGE, and Earth cores will be GREEN YELLOW.
The Color-coding for single-core cables is like this;
AC live will be ORANGE, AC neutral will be LIGHT BLUE, and Earth will be GREEN YELLOW.
So we come back to the original question; what wires in our panel are orange?
Well, firstly we have the panel internal light. We want to be able to see when we turn the main switch off!
Next, we have the socket. This will allow us to keep our laptop charged up.
If the panel needs to be turned off for an extended period of time, then when we are ready to go, our laptop may have died. Not good! The socket is protected by a fuse so that any spikes in power won’t damage our laptop!
The final thing we have in this panel with power is a topic we’ve already covered; the thermostat and cooling fan!
As we’ve already determined, we need to be able to keep the panel cool, even when the main switch is off.
So how does this all work? Well inside the panel, we have the mains feed 3 phase power that comes into the panel to a set of terminals labeled L1, L2, L3, and N.
You can see from this that 1 phase, L1/N, has orange wires in. It is separate from the other wires in this terminal block so that they act independently.
On the back of the main switch on the left-hand door, the wires are identified as L1, L2, L3, and N, matching what we have on the terminals.
The outgoing side of this main switch will be isolated if the switch is off, and will be powered if the switch is on.
The main switch is connected to the contactor labeled 150K1.
When the switch is on, giving power to the panel, this contactor will be pulled in or energized.
Once this is energized, power can be distributed around the rest of the panel.
So sometimes we need to put the main switch or the panel isolator in the OFF position and that will turn off the electrical control panel for an extended period of time BUT when that happens we want to keep the power on for the following devices inside the panel:
a) Panel internal light; as we want to be able to see when we turn the main switch off!
b) Socket outlet; to keep our laptop charged up. The socket is protected by a fuse so that any spikes in power won’t damage our laptop!
c) The thermostat and cooling fan; as we need to be able to keep the panel cool, even when the main switch is off.
Hopefully, you’ve learned the orange wires secret. It’s important to remember this one. It could save your life! Now you’ve learned the SHOCKING truth behind the orange wire, what’s next?! Stay tuned to find out!
This article was brought to you by RealPars in partnership with Pro-control in the Netherlands.
They are experts at control system design and industrial automation. They have a team of world-class automation engineers and have been designing and implementing industrial control systems in different industries for many years.
If you want to get in contact with them, you can check out their website at pro-control.nl.
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The RealPars Team
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