Answers to common questions about UL 508A industrial control panels, SCCR ratings, panel costs, build times, and working with Sterling Made.
UL 508A is the safety standard for industrial control panels published by Underwriters Laboratories. A panel shop that holds a UL 508A listing has demonstrated that its manufacturing processes, quality system, and finished products comply with the requirements of the standard, and is authorized by UL to apply UL labels to the panels it builds.
The standard covers the construction, wiring, testing, and marking of industrial control panels. It addresses topics including short-circuit current ratings (SCCR), spacing and insulation requirements, overcurrent protection, grounding, and enclosure suitability. Panels built by a UL 508A listed shop carry a UL label that tells the authority having jurisdiction (AHJ) — typically an electrical inspector — that the panel was built by a qualified manufacturer following a documented quality system with regular third-party audits. For end users and specifiers, requiring UL 508A listed panels is the standard way to ensure compliance with the National Electrical Code (NEC), specifically Article 409, which governs industrial control panels.
SCCR stands for Short-Circuit Current Rating. It is the maximum fault current, in amperes, that a control panel can safely withstand without creating a fire or shock hazard. Every industrial control panel installed in the United States is required to have a marked SCCR per NEC Article 409.110.
SCCR matters because a panel installed at a location where the available fault current exceeds the panel's SCCR is a code violation and a safety hazard. Under UL 508A, SCCR is calculated using the methodology described in Supplement SB. The calculation considers every component in the power circuit — circuit breakers, contactors, overload relays, terminal blocks, and wire — and determines the weakest link. The panel's overall SCCR is limited by the lowest-rated component or combination in the circuit. At Sterling Made, SCCR is calculated and verified per UL 508A Supplement SB on every panel we build. The SCCR worksheet ships as part of the standard document package.
Most custom industrial control panels cost between $2,000 and $50,000 or more, depending on size, complexity, and component selection. A simple motor control panel with a few starters might fall in the $2,000–$5,000 range. A large PLC-based panel with VFDs, HMI, networking, and multiple power circuits can reach $30,000–$50,000+.
The primary cost drivers are: components (PLCs, VFDs, HMIs, circuit breakers, contactors), enclosure (size, material, NEMA rating), engineering and design (for design-build projects), labor (wiring, assembly, testing, QC), and documentation. Sterling Made provides detailed line-item quotes so customers can see exactly where the cost comes from. Our quote turnaround is 24 hours from receipt of specifications.
The industry average lead time for a custom industrial control panel is 8 to 12 weeks from purchase order to shipment. Sterling Made's standard turnaround is 3 weeks from drawing approval to shipment.
Sterling Made achieves faster turnaround through lean operations with minimal queue time between stages, proactive procurement that begins immediately upon PO receipt, and a focused production model where your panel gets direct attention from the founders rather than waiting in a queue behind dozens of other jobs. Customers receive milestone updates at five stages: design approval, procurement complete, wiring started, testing complete, and shipped with tracking.
UL 508A covers industrial control panels used in general industrial applications. UL 698A covers industrial control panels used specifically in hazardous (classified) locations — areas where flammable gases, vapors, liquids, combustible dusts, or ignitable fibers may be present.
UL 508A is the standard most panel shops are listed under, covering the vast majority of industrial applications. UL 698A applies when the panel itself is installed in a hazardous location (Class I, II, or III as defined by NEC Article 500). The requirements of UL 698A include everything in UL 508A plus additional construction and testing requirements specific to hazardous environments.
Industrial control panels in the United States are governed by UL 508A (product safety standard for panel construction), NEC Article 409 (installation requirements), and NFPA 79 (panels as part of industrial machinery).
UL 508A covers construction requirements, SCCR calculations (Supplement SB), spacing, overcurrent protection, grounding, wiring methods, and testing including hipot testing per Section 60. NEC Article 409 requires panels to be marked with SCCR, supply voltage, phase, frequency, and other nameplate data. NFPA 79 applies when the panel is part of a machine and adds requirements for emergency stop circuits and control circuit protection. Additional standards that may apply include UL 698A (hazardous locations) and NFPA 70E (arc flash).
Sterling Made is headquartered in Greater Boston, Massachusetts. Our panel shop serves customers throughout New England and nationwide.
Being based in Massachusetts puts us within a 2–3 hour drive of most industrial facilities in New England. For customers in our local area, we offer hand-delivery of completed panels within a 150-mile radius. For customers outside New England, we ship nationwide via freight carrier. Contact us at quotes@sterlingmade.com or call 617-256-3460.
Sterling Made builds UL 508A industrial control panels for customers across water and wastewater treatment, pharmaceutical and biotech manufacturing, food and beverage processing, building automation, and packaging and material handling.
Regardless of industry, every panel we build goes through the same 48-point QC inspection and ships with a complete document package including as-built drawings, test records, BOM, SCCR worksheet, nameplate data, and component data sheets.
Sterling Made returns quotes within 24 hours of receiving your specifications. The industry average for quote turnaround is 5 to 10 business days.
To generate an accurate quote, we need either a set of electrical drawings (schematics, panel layout, BOM) for build-to-print work, or a functional description and I/O list for design-build work. Our quoting process produces a detailed line-item breakdown — no lump-sum mystery pricing. Email your specifications to quotes@sterlingmade.com or call 617-256-3460.
Every panel built by Sterling Made ships with a complete document package including as-built drawings, test records, a bill of materials (BOM), an SCCR calculation worksheet, nameplate data, and component data sheets.
As-built drawings reflect the panel exactly as built. Test records include hipot test results per UL 508A Section 60. The SCCR calculation worksheet shows methodology per Supplement SB. Nameplate data includes all required marking per NEC Article 409.110. This documentation supports commissioning, future maintenance, and electrical inspections by the AHJ.
Yes. Sterling Made offers PLC programming as part of our full-stack service model. We design, build, program, commission, and support industrial control panels.
Our programming capability covers major PLC platforms and includes ladder logic, structured text, and function block programming. We also configure HMI screens, set up industrial networking (EtherNet/IP, Modbus TCP, Profinet), and perform factory acceptance testing (FAT). If you already have your own controls engineer handling programming, we work equally well as a build-to-print or design-assist partner.
Sterling Made works with all major industrial control component manufacturers including Allen-Bradley (Rockwell Automation), Siemens, ABB, Schneider Electric (Square D), Eaton, Phoenix Contact, Weidmuller, Wago, Rittal, Hoffman, Hammond, and AutomationDirect.
We are not locked into any single vendor ecosystem. We build with whatever components your specification or application requires. All components are sourced from authorized distributors. We verify UL file numbers on every component before installation to ensure compliance with UL 508A requirements.
Outsourcing to a dedicated UL 508A listed shop makes sense when your team's time is better spent on engineering, field installation, commissioning, or customer-facing activities. Building in-house makes sense when you have dedicated panel builders on staff and enough volume (typically 30+ panels per year) to justify the overhead.
In-house panel building requires shop space, a UL 508A listing ($5,000–$15,000+ initial cost with annual maintenance), quarterly UL audits, calibrated test equipment, component inventory, and trained builders. When you factor in the fully loaded cost, per-panel costs are often comparable to outsourcing. Many customers use a hybrid approach: simple panels in-house, complex or time-sensitive projects outsourced.
The most important factors when evaluating a panel shop are UL 508A listing status, SCCR calculation capability, quality system documentation, communication practices, and references from similar projects.
Ask to see their UL file number (verify on UL Product iQ), whether their builders are MTR-certified, whether they calculate SCCR per Supplement SB on every panel, what their QC inspection process covers, what documentation ships with the panel, whether test instruments are on a calibration schedule with NIST-traceable certificates, and how they communicate during the build.
Design-build means the panel shop creates the electrical drawings and then fabricates the panel. Build-to-print means the customer provides completed drawings and the panel shop fabricates the panel exactly as specified.
Build-to-print is most common with system integrators who have their own controls engineering. Design-build is valuable when the customer lacks in-house controls engineering or wants a single point of responsibility. Sterling Made also offers design-assist — a middle ground where we fill gaps in partial designs before building.
Email your specifications to quotes@sterlingmade.com or call 617-256-3460. We return quotes within 24 hours.
Send us electrical drawings for build-to-print, or a functional description and I/O list for design-build. After you review and approve the quote, we confirm a ship date within 24 hours of PO receipt. You receive milestone updates at five stages throughout the build. Every panel goes through our 48-point QC inspection before shipping.
For build-to-print: provide electrical schematics, panel layout, and BOM. For design-build: provide a functional description, I/O list, and any applicable specifications.
Additional helpful details include: supply voltage/phase/frequency, preferred PLC platform or component manufacturers, NEMA enclosure rating, environmental conditions (indoor/outdoor, temperature, washdown), target SCCR or available fault current, and project timeline. Even if you only have a rough idea of what you need, contact us — we offer design-assist services to help develop the specification.
Yes, Sterling Made offers expedited builds on a case-by-case basis. Our standard turnaround is 3 weeks from drawing approval. For tighter timelines, we evaluate feasibility based on component availability and current shop capacity.
Rush builds are subject to component lead times — the build itself can often be compressed, but long-lead components become the constraint. We recommend contacting us early so we can begin procurement research before the PO is issued. In some cases, pre-ordering long-lead components against an anticipated PO can save weeks. Contact us at quotes@sterlingmade.com or 617-256-3460.
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