What are Electrical Prints?

Electrical Prints

When looking inside a control panel it can get overwhelming, especially when the wire-covers are removed.  We at Vulcan know this is a necessary evil, but we are constantly looking for smarter and more intuitive ways to make this easier for installation and troubleshooting in the field. This article goes in depth into what electrical prints are and how to effectively read them.

Many of our units have between 300 and 500 wires.  Even if a unit has one wire, it is essential that it is numbered or labeled somehow.  Accurate numbering of wires is essential for consistent process excellence.  Electrical prints are also made specific for each unit we manufacture and are included with the Control Panel when shipped.

What Basic Electrical Prints Looks Like

Lets take a closer look at a basic print and highlight key areas of concern so that when you receive your order, you will be a confident step ahead of the game.


First, look at the TOP-RIGHT corner of the page.  You will see Letters on the Right (vertical), and Numbers on the Top (horizontal).  Much like the game of Battleship, you can pinpoint exact locations on the page.  Some locations in the print will have an ARROW like this:

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This designates that it is Wire# 1162 from Page 5 at coordinates C12

Wire # 1162 is a common number in our control circuit, as it is the 120Vac (hot) that feeds many applications.

Wire # 1171 is another common wire as it is the 120Vac neutral (usually a white wire for ease of identification).

You are probably asking “Why such an odd number for a common wire?  Why did you choose that?”  I am glad you asked because that brings us to our next item to cover.

Wire Numbering and What they Mean

We at Vulcan Drying Systems have established a standardized method of numbering every wire and is consistent for every unit we produce.  Highly customized units will necessarily deviate where practical, but in general you can be assured that the method is sound.  Below is an example of our prints.

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Notice the Blue Identifier numbers on the Left side.  These numbers continue increasing incrementally throughout the print and assist the worker to understand where any wire # can be located.  As you can see, Wire 40 aligns with the 4.  This will allow for up to 10 wires (40-49) to be utilized between the 4 and 5 Identifiers.

Wire# 1162 can be found on Identifier 116 and

Wire# 1171 can be found on Identifier 117 (see below)

We have established that the Transformer T1160 (480-120Vac) will be on these Identifiers on roughly every print we design.  Yes, even all components are also Labeled, Numbered and will be located in just the same fashion.

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Finally we want you to be aware of the  icon.  This is a specific logo used to identify that a wire is landed on a terminal strip (see below)

What Are Terminal Strips?

Terminal strips are widely used in the field to easily land incoming wires for various applications.  Per the above picture, the eight E-Stop terminals (ES-1 thru ES-8) with jumpers for potential future upgrades (Read the E-Stop blog for more information) are on the left.  The next 10 terminals are designated for the 1162 bus (X1 thru X10).  The next 10 are for the 1171 neutrals (X11 thru X20).  Another 10 are standard for items like a Baghouse Pulse system, or a Knife-Gate system, or any other customized needs you may have (X21 thru X30).  The last block of 15 terminals is for Burner Control (BC-1 thru BC-15).  As you can see, all pre-wiring is done on one side of those terminals; your unit will have wires properly numbered to be landed on the opposite portion, directly above their assigned numbers.

Every effort has been made to simplify field installation and maintenance.  Remember to have a properly qualified person to do all electrical work and to always take all necessary safety precautions.

Need Help?

Vulcan is here to assist you in your electrical or industrial drying solutions projects. With over 50+ years of experience in both fields, you can count on us to help you get your job done right.

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