Quality Products
Our products are rigorously tested and cleaned, backed by a 2-year DO Supply warranty.
DO Supply is a global automation parts reseller focused on hard-to-find and obsolete industrial automation products. Based out of Raleigh, NC, we service customers worldwide, providing excellent customer and sales support, as well as offering our top-of-the-line warranty on all parts sold.
Our products are rigorously tested and cleaned, backed by a 2-year DO Supply warranty.
We offer various shipping options from UPS, FedEx Priority Overnight, DHL and similar. We also ship internationally via DHL, FedEx, and UPS.
While other automation experts have some expertise, we have nearly half a century, allowing us to help you find the ideal replacement or repair solution.
We are a leading global supplier of industrial automation replacement parts, dedicated to providing expert support, speed, and reliability. We offer a huge inventory of need-it-now surplus PLCs, drives, motors, HMIs, and more. Trusted worldwide, we supply parts from 1981 to today by manufacturers such as Allen Bradley, GE, Eaton Cutler Hammer, Mitsubishi, Johnson Controls, and more. With an extensive inventory of surplus products, we are sure you will find what you are looking for. Our commitment to quality and service is reflected in our A+ Better Business Bureau rating. We guarantee prompt delivery and responsive support, empowering businesses to streamline operations and enhance productivity through reliable automation solutions
We pride ourselves on being your need-it-now destination, specializing in immediate solutions for hard-to-find and obsolete replacements for PLCs, drives, motors, HMIs, and more.
Save money with our repair service backed by a 2-year DO Supply warranty, serviced by US-based technicians.
As industrial automation specialists, we focus on top brands like Allen Bradley, GE, Eaton Cutler Hammer, Mitsubishi, and Johnson Controls, sourcing hard-to-find and discontinued parts. Our dedicated team ensures quality through meticulous testing and repairs. With fast shipping and exceptional customer service, we offer a seamless experience. Plus, our in-house repair technicians provide repair services for most products.
Discover insightful industry knowledge
ControlLogix communication delays are often not the fault of a single component. In most field situations, the culprit is not a broken device but a design misalignment among the controller’s capacity, the choice of communication module, and the network built around it. A ControlLogix system is modular, and delays often trace back to a specific design decision: too many nodes on the I/O bus, the use of an antiquated bridge module, or a backplane routing configuration stretched beyond its performance envelope. Getting a strong grip on these mechanics and moving away from thinking of delay as just a generic “network problem” is what will distinguish a permanent fix from a temporary workaround. Every ControlLogix controller has an upper limit on the number of nodes and connections it can support, and exceeding that limit is one cause of communication lag. A node is any device added to the I/O configuration, and pushing a network beyond that count can cause delays that no amount of...
In PowerFlex variable-frequency drives (VFDs), the DC bus functions as the internal power bridge and electrical reservoir between the AC input rectifier and the output inverter stage. Once the incoming AC line voltage is rectified, the DC bus capacitors smooth and stabilize the resulting DC bus voltage by reducing voltage ripple, thereby delivering a steady DC supply to the inverter. They also temporarily absorb the regenerative energy produced during overhauling-load conditions or motor deceleration, reducing rapid voltage fluctuations and improving energy efficiency. This article provides a comprehensive overview of the fundamentals of DC bus voltage in Allen-Bradley PowerFlex drives. Knowledge of pre-charge drive operation, DC bus capacitors, shared DC bus configurations, DC bus regulation, regenerative energy management, and common DC bus-related faults enables engineers and maintenance personnel to maximize the reliability of PowerFlex drives, improve overall system performance...
Modern motor control relies heavily on variable frequency drives, yet the components that safeguard them are often the first to suffer budget cuts. Line reactors, also known as input reactors, are often seen as optional add-ons rather than necessary safety measures. The electrical mechanics underlying reactor protection, the failure types that reactors avoid, and the cost justification for implementing them on each drive installation are all discussed in this article. In simple terms, an input reactor is a three-phase inductor placed between a drive’s input terminals and the incoming AC power source. Its purpose is surprisingly straightforward: it increases the line’s impedance. In a drive environment, this impedance smooths out the abrupt current spikes that occur each time the drive’s rectifier bridge charges its DC bus capacitors, as it resists rapid current changes. Drives convert incoming AC to DC using an SCR bridge rectifier or diode. Because the current is drawn in brief...