In this video, we walk through the process of designing and building a typical industrial
control panel.
We'll start by identifying what the machine will do, then draw a block diagram of the
components and how they'll interconnect.
Next, we'll pick the part numbers, draw the schematics, and design the panel layout.
Finally, we'll assemble, wire, and test the completed system.
This panel will be a remote I/O installation and the controls are going to be used to run
a Flying Cutoff machine.
We'll be using a PS-AMC4 with a P1-RX, for communication back to the primary controller,
and four SureServo2 drives.
We're also going to highlight some of the other components AutomationDirect offers that
can make your job easier, like Rhino Pro DC power supplies, Wago electronic circuit breakers,
and Reer safety controllers.
The PS-AMC 4 will control four SureServo 2 drives, and the P1-RX will let us control
it all from an existing Productivity PLC.
The Rhino Pro power supply will power our control system, and the Wago electronic circuit
breaker will distribute and protect our DC power.
Now that the machine's purpose has been defined and the components selected, we'll draw our
block diagram.
If you've heard of a one-line drawing, you'll be familiar with the concept here.
We just want to document the relationship between all the parts we're using, from supply
power, through circuit breakers, to the components they power and to the sensors or motors they
control.
At this point, it's not important to know the manufacturer or model number of the parts
you're using, but for the example we already do.
Note that we're not even looking for pin numbers or individual wires currently, just the relationships
between components.
It's time to discuss schematics.
These are the drawings you'll use to wire components together.
It's important to have a plan and stick to it.
While there's no wrong way to organize your schematics, some localities or customers may
require a particular style or method.
IEC and NFPA styles communicate the same information in slightly different ways.
Choosing one style over another is outside the scope of this video.
For this example, we're choosing a hybrid approach, where our pages are grouped by function
and our wires are identified by potential, page, and line.
We've chosen to identify all wiring that carries unswitched and AC power with a formula built
like this: The first part is the voltage potential.
The second part is a combination of the page number, the line number, and the column ID
where the wire originates.
This way, if someone is troubleshooting the machine, they can look at any wire and know
where in the schematic to look.
Point-to-point connections are described by the schematics.
This goes farther than the block diagram by describing where every wire lands.
If you don't have specific model numbers chosen yet, your descriptions will still be generic,
for example the AC input to a power supply will be labeled 'L', 'N', and GND', where
a manufacturer may assign pin numbers to these connection points instead.
The last steps in the schematic package go hand-in-hand: choosing your specific parts
(or Bill of Materials) and designing the physical layout of the control panel.
In an ideal world, you'd be able to fully design your schematic, pick your parts, design
your layout, and then choose a cabinet and subpanel that has room to spare, but reality
can get in the way.
Often, you'll be given a space to put a cabinet, and you'll have to do your best to fit everything
inside while keeping thermal considerations and voltage separation in mind.
With that said, we've chosen this layout with a few things in mind.
Three-phase power comes in on the right, into the main disconnect, and back into the AC
circuit breakers in the top row.
The right side was chosen for the main disconnect since this cabinet has a cable-driven handle
that mounts on the right side.
The servo drive gets the bottom row for two reasons: first, this allows heat to rise away
from the servo drives, and second, if we bring the servo cables in from the bottom of the
cabinet, we don't have to worry about voltage separation for the servos.
24-volt DC power and signals stay to the left.
Areas where 3-phase power and low-voltage DC power have to get close to each other are
separated by wire duct dividers.
Ethernet cables get their own bundle but can share space in the wire duct with 24-volt
wiring.
Keeping with the theme of a bottom exit for cables, the PLC's I/O terminal blocks are
placed at the bottom-left of the panel.
Additionally, components are spaced away from wire duct and other devices based on their
installation manuals.
This is done so these parts don't overheat under heavy load.
Now that the decision where everything goes on our control panel has been made, it's time
to mark the lines and plan the holes.
Using a T- square and a mechanical pencil, measure and mark the lines where the DIN rail
and wire duct will be installed.
The square helps keep the lines straight, and the mechanical pencil will draw a clear
line so that it's easy to erase later.
Mark the mounting holes through wire duct and DIN rail, as well as any components that
mount directly to the subpanel.
When marking DIN rail mounting holes, give them a unique mark to help you know which
holes to bond for grounding.
Before beginning, PPE or safety glasses are important.
Use a center punch to mark a divot in the center of each hole marked.
Then, using a #40 or 3/32'' drill bit, drill pilot holes.
Cutting oil helps keep the drill bit cool and sharp.
Using an 8-32 drill/tap bit and plenty of cutting oil, cut threads in every pilot hole
that will be used to attach wire duct and DIN rail.
Other components like VFDs and disconnects may require different screw threads.
Once all holes are drilled and tapped, deburr every hole on both the front and the back of the
subpanel.
Deburring every hole will keep your screws aligned during installation and protect your
hands from cuts and scrapes.
Now that all your holes are drilled, tapped, and deburred, use a bonding brush to remove
any paint around the holes that will be used to attach DIN rail, as well as any non-DIN
components that require a case ground.
Carefully wipe off any metal shavings from the panel, then use WD-40 to remove any remaining
pencil marks, and finally, use isopropyl alcohol to clear any remaining residue and allow the
panel to air-dry.
Now it's time to start adding parts to the panel.
Start with wire duct, and carefully align the segments with precise right angles using
Eight-thirty-two panhead screws.
Do the same with the DIN rail sections.
Time spent here making the angles precise will pay off later in the build, and will
improve the final appearance, maintaining a professional look.
When everything is properly aligned, tighten the screws firmly, especially the screws on DIN
rail, since they're being used to bond the DIN rail to the subpanel.
Starting with DIN rail end blocks, attach all components to the panel based on the layout
design.
Keep components tight against end blocks to help them stay in place during and after the
build.
When installing terminal blocks, take advantage of jumpers or bridges available for the parts
being used.
They can save a ton of time by eliminating hand-made jumpers.
As components are installed, you may find that some fingers on your wire duct will get
in the way of larger wires or cables.
Luckily, wire duct is designed to accommodate this.
Simply remove the cover of the wire duct and bend the fingers away from the center of the
duct.
They're scored from the factory and will cleanly snap free.
Be careful with this, though -
once a duct finger has been removed, it's off for good.
Using the schematic package as a reference, apply labels identifying the components and
terminal strips.
Applying labels on the subpanel is preferred, but for terminal strips or PLCs with wiring
that runs above and below the device, wiring may get in the way of the label.
In this case, applying the label to the duct cover is acceptable.
Just be aware that years down the road, that cover may go missing!
For terminal strips, use marking tags to label each terminal.
Now it's time to start wiring the panel.
The order doesn't really matter but having a system for yourself is a great way to ensure
nothing is missed.
For this build, we're starting at the first page and working our way to the last.
If it makes more sense for you to wire your I/O before your power distribution,
there's nothing wrong with that.
Be sure to mark the connections and pages as you go, so you don't risk duplicating or
skipping work.
When wiring, crimping ferrules on the ends of your wires will keep stranded wire from
fraying, reducing the likelihood of a short or bridge, making it easier to install wires
in terminal blocks.
Route wires carefully so higher voltages stay away from lower voltages.
For example: on this panel, we've routed the three-phase power up the right-side duct,
through the main disconnect, and back around to the AC circuit breaker bus lugs.
Then the AC power wires run out the bottom of the breakers and back down the right side
of the panel to the four servo drives.
The power feed to our DC power supply is the only higher-voltage run that goes to the left,
and since it must live in the same section of wire duct as some lower-voltage wiring,
a section of duct separator is installed.
If there are locations where high and low voltage wires need to cross, be sure they
cross at a right angle.
This will reduce inductive coupling, which can introduce noise or signal fluctuations
on wires nearby.
Also, make sure that any wires that share the same duct are all rated for the highest voltage
that will be present.
As you cut, strip, and crimp the wires, be sure to label them to match the schematics.
Multicore cables should be labeled differently, to identify that they are distinct from single
wires.
Labeling individual conductors with a multi core cable isn't necessary unless the cores
are landing far away from the labeled end of the cable's jacket.
Once the wiring is complete, it's time to test it.
Be aware: the panel build may involve higher voltages that can be dangerous, so wear safety
glasses and any other required PPE safety gear and follow all local laws and codes to
ensure your safety.
Start by attaching the supply power and ground.
DO NOT SKIP YOUR GROUND!
Particularly during testing, the ground wire is there to protect you and the wiring by
providing a safe path for errant power away from the panel.
If you don't install a safe return path, you may become the return path!
Use a multimeter to verify the incoming voltage is what is expected.
Next, turn on the circuit breakers one at a time, making sure the expected device turns
on with each one.
Once each AC device is tested, turn off unneeded devices to limit the risk of shock or arcing.
Leave the DC power supply powered on and move to your DC circuit protection.
In this panel, we've used an electronic circuit breaker for all the DC components, but of
course electromechanical circuit breakers or fuses would be acceptable.
Turn on the DC components one at a time, making sure the expected device turns on, and that
nothing powers up unexpectedly.
Check for power where you expect it.
For example: the power rail of I/O terminal blocks, or the input side of a safety relay.
Leave all your DC components powered for the remainder of testing.
If everything checks out, it's time to move to I/O testing.
Connect to the PLC and configure it with the I/O installed.
Use a jumper wire to apply power (or common if your inputs are sourcing) to each input
terminal block, making sure the correct input is activated in the PLC.
Next, use the PLC's programming software to enable each discrete output, one at a time,
and verify the selected output turns on and off as expected.
Verify this at the expected terminal block.
Some discrete inputs and outputs may require activation of the safety system, if equipped.
If this is the case, connect the appropriate safety inputs, activate the system normally,
and continue with the testing.
To test analog inputs, use a current or voltage simulator and verify the PLC is indicating
the expected value.
If you don't have a simulator, you can use an analog device of the same signal type and
wire it to each terminal, one at a time.
To test analog outputs, use the PLC programming software to set the output value to a unique
level for each channel and use a multimeter in the appropriate mode to verify the expected
readings at the terminal block.
If any channel doesn't operate as expected, make sure the I/O card has input power and
the wiring is correct.
Lastly, it's time to load the final PLC program, if it's ready.
Use the programming software to open the file and transfer it to the PLC.
Depending on the application and program, you may be able to perform a full-function check at
this time or this may be where testing ends until the panel is installed on the machine.
Thanks for watching and we hope that our video was informative.