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Millions of parts are available for same-day shipping and next-day delivery.
Save money on downtime with the most trusted leading experts in automation replacement and repair.
Millions of parts are available for same-day shipping and next-day delivery.
45+ years of experience to help you find an ideal replacement or repair solution.
We stand behind our quality by offering a complimentary 2-Year DO Supply Warranty on all products.
DO Supply is a global leader in replacement parts for industrial automation equipment. Our mission is to elevate the standard of expert support, speed, and reliability for your need-it-now automation replacement and repair needs. Whether it's PLCs, drives, motors, HMIs, or more, you can count on us for the best service and fastest solutions.
Shop with confidence knowing that we offer fast shipping and best-in-class customer service. Explore our large inventory of in-stock automation parts backed by the guarantee of a 2-year DO Supply Warranty.
Save money on getting your automation parts repaired for less, backed by our 2-year DO Supply Warranty. We offer quality repairs at the best prices, carried out by expert technicians.
We want to buy your industrial automation surplus equipment, including PLCs, drives, motors, HMIs, and more.
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Surplus Allen Bradley, GE, Fanuc, Emerson, Eaton, Mitsubishi, Omron, and more.
Discover insightful industry knowledge
One of the most annoying diagnostic situations in industrial drive maintenance is a nuisance overcurrent issue. When the PowerFlex trips, production stops, the operator resets it, and it functions normally for many hours before tripping again for no apparent reason. Nuisance overcurrent faults are condition-dependent, sporadic, and seldom self-explanatory from the fault code alone, in contrast to a hard fault brought on by an obviously malfunctioning component. An overcurrent fault is a precise diagnostic signal intended to prevent damage to the motor, drive, and related equipment. It shows up as a strong, abrupt current spike that exceeds the drive’s hardware limits. Diagnosing any PowerFlex model, from the tiny 525 to the architecture-class 755T, depends on understanding what causes these spikes and distinguishing between hardware-level and software-level overcurrent detection. When diagnosing a PowerFlex overcurrent problem, the first thing to consider is whether the event is...
One of the most important decisions in industrial motor control is choosing the right Variable Frequency Drive (VFD), or AC drive, to match your motor and application requirements. Proper AC drive selection begins with understanding the mechanical load characteristics because the load type determines the current and torque requirements the selected AC drive and connected motor must meet across all operating speeds. An appropriately sized AC drive provides adequate continuous and overload current capability to generate the required motor torque while operating reliably. Selecting an incorrectly configured or improperly sized AC drive often results in insufficient starting or accelerating torque, excessive drive or motor heating, reduced efficiency, nuisance trips, and premature equipment failure. In contrast, an AC drive that is correctly matched to the specified load type helps improve motor performance, operation reliability, energy efficiency, and overall system lifespan. Because of...
When choosing a PLC, the system’s architecture affects all subsequent engineering work, from how control panels are drawn to the cost of maintaining the system over years of service. Most PLCs fall into one of two competing design philosophies: modular architecture, where the I/O, CPU, and power supply are separate elements on a common backplane, or fixed architecture, where all of these are combined in a single housing. Every major PLC vendor offers product lines that follow both designs, and understanding how each platform is laid out helps an engineer pair architecture to application rather than defaulting to whatever solution is already sitting on the shelf. Comparing the five largest control vendors in Europe, North America, and Asia – Rockwell, Siemens, Schneider Electric, Mitsubishi, and Omron – all of which market modular and fixed models side by side – shows which factors vendors weigh when dividing fixed and modular I/O architectures. The real tradeoffs come down not to...