New Power Distribution Blocks

Electrical Control Engineers now have a valuable new alternative to traditional Power Distribution Blocks (PDB’s) and Fuse Holders.  Marathon Special Products, a Brand of Regal Rexnord has developed several products that incorporate push-in wire termination technology.  

Push-in terminals are nothing new to control panels.  However, they are almost exclusively used in the control or signal circuits of these panels that do not carry the power needed to supply motors, heating elements and other higher power devices.  As push-in wire technology has evolved to handle larger wire and higher power, there is a trend to incorporate that into the rest of the control panel, including the power circuits.  Until recently, few power distribution components like relays and motor contactors have been equipped with these terminals.  Integrating them into the main PDB and branch circuit protection devices provides more reliable connections that simplify the connection process at the point of manufacture. 

Push-in terminals offer more than just time savings.  Time savings of up to 70% is commonly cited, but the unseen benefits of removing the application of torque to terminate a wire, can provide enormous value.  Eliminating the torque process for EACH wire eliminates a specialized torque tool as well as the skilled labor to apply it.  If done properly, traditional terminals are still reliable solutions.  If not done properly, terminals can overheat or pull out resulting in a catastrophic short.  Push-in terminals eliminate the risk and potentially catastrophic results of improperly torqued wires that could happen due to tool or human errors. 

Another growing trend that these products complement is the use of ferrules.  A wire ferrule is simply compressed on to the bare ends of the wires to hold stands together so they do not fray and short out.  Ferrules are also typically required for all panels used in Europe (under CE standards).  The use of robotic equipment to add ferrules is also more readily available and used by control panel manufactures.  When using ferrules, larger push-in wire terminals are much easier to use.  Instead of pushing in the button or spring with a common flat head screw driver, you can simply push the ferruled wire into the product.  If you are developing wire harnesses that add ferrules to the wires robotically, the use of these PDB’s and Fuse Holders serves to add more value, more reliability and more simplification to your product.  

Additionally, the new PDB’s are also UL Listed and touchproof,  Although many companies are still using UL Recognized terminal blocks in the feeder circuits, it is not in compliance with the latest UL508A standard that requires UL1953 Listed PDB’s.  These PDB’s have considerably increased spacings to help prevent shorts at this point where many wires are coming together to draw and distribute large amounts of power. 

To learn more about these new products and their benefits, please see our overview video here.  To learn more about Marathon Special Products and our product offering, please visit us at