What Is NETA and How Does Testing Apply to the ICT Industry?
NETA specifications aren’t just an item you need to check off your to-do list. It’s the marker that
ensures your power distribution equipment and electrical systems are safe, reliable and ready
for heavy-duty work. As the gold standard for industry best practices, NETA testing is what
catches any potential issues before they grow into red flags.
But what exactly is NETA and how does it apply to specialized step-down transformers, like
Industrial control transformers, or ICTs? Let’s break down what you need to know.
Why NETA Matters
NETA, or the International Electrical Testing Association, is an American National Standards
Institute, or ANSI, accredited organization founded in 1972.
The group acts to maintain industry standards for electrical power testing and sets specifications
for:
- NETA Acceptance Testing Specifications (ATS)
- NETA Maintenance Testing Specifications (MTS)
- Technical certification
- Accreditation for independent, third-party testing companies
How Does NETA Testing Impact ICTs?
Industrial Control Transformers (ICTs) are built to supply low-voltage power sources for control circuits. Here’s where confusion often arises: ICTs aren’t explicitly covered by NETA standards.
While power transformers must follow ATS for acceptance and MTS for maintenance, ICTs are designed and certified to UL 5085 and guided by NEMA ST‑1. Think of UL/NEMA as the design and safety rulebook, and NETA as the field manual you can adapt for added reliability.
NETA testing complements UL/NEMA by validating installation quality and in‑service reliability. Here’s how:
- Electrical Safety & Integrity: If not maintained correctly, power equipment can quickly malfunction, leading to injury, fires and outages. NETA testing ensures windings, insulation and other electrical connections meet specific manufacturer tolerances and ANSI standards.
- Reliability: Will your system hold up under stressful conditions? ICTs must maintain secondary voltage stability under certain conditions. NETA testing validates this by checking that control circuits are performing as they should—and not tripping or failing.
- Compliance: Electricity can be a liability. When facilities participate in NETA testing and proper risk management, it is easier to identify installation errors (such as loose terminations or incorrect grounding) and validate compliance with ANSI/NETA ATS-2025 standards. All of this is essential for most insurance coverage and to stay in compliance.
- Optimization: NETA testing filters out issues as they first surface and before they can take root. Under NETA MTS, regular testing can catch insulation breakdowns or overheating. This can extend equipment life and boost operational efficiency.
What NETA Standards Apply to Industrial Control Transformers?
Two key standards apply to ICTs:
- ANSI/NETA ATS (Acceptance Testing Specifications): Used when ICTs are first installed. It checks things like insulation, winding ratio, and proper connections before energizing the system.
- ANSI/NETA MTS (Maintenance Testing Specifications): Used for ongoing maintenance. It ensures the transformer stays safe and reliable by testing insulation, winding resistance, and looking for signs of wear or overheating.
Both of these standards help prevent catastrophic failures and improve safety, while ensuring control circuits continue to run smoothly.
When Should You Follow Which Standards?
While it may seem confusing, there’s a simple way to understand when ICTs follow which NETA Standards:
- Before you flip the switch – Use ANSI/NETA ATS (Acceptance Testing Specifications) at installation or before first energization.
Why? ATS is like your initial checklist. It confirms the transformer is correctly installed, wired and meets manufacturer specifications before anything goes live.
- To keep things running smoothly for the long haul – Use ANSI/NETA MTS (Maintenance Testing Specifications) during scheduled maintenance or after repairs.
Why? MTS is your regular tune-up. It detects aging issues like insulation breakdown, loose connections or overheating to keep systems safe and reliable.
- For construction and performance certification – When evaluating or certifying an ICT, follow:
- UL 5085-1 / 5085-2 – Governs construction and performance requirements.
- NEMA ST-1 – Applies to dry-type control transformers.
Why? These standards ensure the transformer’s design and build meet safety and performance benchmarks. You can also adapt NETA-style test methods for documentation consistency.
Do NETA Standards Differentiate between Power Transformers and Industrial Control Transformers?
NETA standards are mandatory for power transformers, but optional and adaptable for ICTs—giving users flexibility.
| Factors to Consider | Power Transformers (covered by NETA) | Industrial Control Transformers (ICTs) |
| Typical Size/Use | >15 kVA, power distribution | <5 kVA, machine, or panel control voltage |
| Applicable NETA Standard | ANSI/NETA ATS/MTS (Section 7.9) | Not explicitly covered |
| Relevant Tests (adapted) | Ratio, polarity, insulation resistance, winding resistance | Optional/adapted versions for QC |
| Governing Design Standard | IEEE C57.12 series | UL 5085 (formerly UL 506), NEMA ST-1 |
| Inspection Focus | Electrical integrity, ratio accuracy, insulation and oil tests | Control voltage output, impedance, inrush and dielectric strength |
NETA Testing is the Benchmark for ICT Safety & Reliability
While ICTs aren’t explicitly covered under NETA standards, adapting ATS and MTS practices—alongside UL and NEMA requirements—adds an extra layer of assurance. The goal is simple: keep your systems safe, compliant, and ready for today’s demanding operations.