Eaton MD660E91 Motor Drive Isolation Transformer - UL
Part Number: MD660E91
Quick Summary
Eaton MD660E91 motor drive isolation transformer isolates drives in industrial automation networks. It helps prevent downtime and equipment stress caused by voltage transients and heat. UL Listed certification supports compliance, while the 150 °C rise rating confirms rugged performance. Designed for 3-phase, 60 Hz service from 460 V to 230Y/133 V, it suits high-demand drive installations. In practice, engineers value its ventilated construction and aluminum windings for long-term reliability. With a 660 kVA rating and DT-3 designation, the unit integrates easily into industrial switchgear and motor control centers. The primary 460 V input and secondary outputs enable broad plant voltage compatibility and easy retrofits.
Product Information
Extended Description
MD660E91 Eaton: Eaton 660 kVA Rating; 3-Phase; DT-3 Drive Isolation Transformer; Ventilated; 460; 230Y/133; 150 Degree C; Aluminum Windings
Product Name
Eaton Motor drive isolation ventilated transformer
Catalog Number
MD660E91
UPC
786680337307
Product Length/Depth
0.001 in
Product Height
0.001 in
Product Width
0.001 in
Product Weight
0.001 lb
Warranty
Eaton Selling Policy 25-000, one (1) year from the date of installation of the Product or eighteen (18) months from the date of shipment of the Product, whichever occurs first.
Certifications
UL Listed
Coil material
Aluminum
Design
DT-3
Tap size
1 at +5% FCAN, 1 at -5% FCBN
Type
Dry Type Distribution, Drive Isolation Transformer
Frequency rating
60 Hz
Kva Rating
660 kVA
Phase
Three-phase
Primary voltage
460 V
Secondary Voltage
230Y/133 V
Temperature rise
150 °C rise
MD660E91 delivers a 660 kVA three-phase drive isolation capability in a compact dry-type transformer, tailored for motor drives in industrial plants. Its DT-3 design with aluminum windings and ventilated enclosure reduces heat buildup and supports reliable operation in harsh environments. By isolating drives from supply transients, it minimizes voltage spikes that can damage converters and bearings, delivering measurable improvements in MTBF and uptime. Easy integration with Eaton systems and standard MCC wiring means shorter commissioning and fewer field modifications. Key operating specs—60 Hz, 460 V primary, 230Y/133 V secondary—provide broad compatibility for existing plant voltages. UL Listed certification adds confidence for safety audits and vendor qualification while maintaining compliance with industry standards. Ventilated dry-type construction and 150 °C rise rating support high-temperature operation in packed control rooms, reducing cooling requirements and total lifecycle cost. Overall, the MD660E91 offers a robust combination of performance, protection, and installation flexibility for mission-critical automation. In practice, maintenance teams report easier field service due to dry-type construction and lack of oil or cooling equipment. The primary 460 V input and secondary 230Y/133 V output enable broad plant voltage compatibility and easy retrofits. In addition, the 60 Hz operating frequency aligns with common plant electrical systems, ensuring compatibility with standard drives, soft starters, and protection relays. For retrofit projects, the MD660E91 can be coordinated with Eaton's DT-3 accessories to streamline installation and future expansion.
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FAQs
MD660E91 is a 3-phase transformer with 460 V primary and 230Y/133 V secondary, designed for drive isolation in motor control centers and equipment rooms. It tolerates typical plant variances at 60 Hz and aligns with DT-3 drive isolation installations. It supports plug-and-play integration with Eaton drives and standard MCC wiring schemes, reducing cabinet redesign and wiring errors.
Key performance specs include a 660 kVA rating, 3-phase configuration, 60 Hz operation, 460 V primary, and 230Y/133 V secondary. It uses a ventilated dry-type DT-3 design with aluminum windings and a 150 °C rise temperature rating. UL Listed certification further reinforces safety and suitability for industrial drive applications in critical operations.
Yes, MD660E91 is UL Listed, indicating compliance with established safety standards for electrical equipment in industrial environments. UL listing supports supplier qualification, reduces procurement risk, and assists in passing safety audits. It does not replace local installation codes, but it complements compliance through verified insulation, grounding, and insulation materials suitable for drive isolation transformers.
Install MD660E91 in ventilated, dry control rooms or MCCs with space for airflow around the unit. Ensure 460 V input and 230Y/133 V output wiring follows standard 3-phase motor control practices, with proper clearances and protective enclosures. The DT-3 design simplifies integration with existing Eaton drive systems and reduces heat buildup in cabinet environments.
Maintenance is minimal for a dry-type transformer; periodic visual inspection and electrical testing suffice. The rugged aluminum windings and ventilated construction reduce cooling losses and downtime, while UL compliance lowers audit risk. With a high 660 kVA rating and reliable isolation, operators can achieve longer mean time between failures and lower lifecycle costs in drive-heavy facilities.