3-Phase 208 D - 480 Y 277 (Step-Up Drive Isolation Transformer)
Size
Estimated Delivery Date: (call to expedite)
Transformer is in stock! Delivers in 5 - 7 business days
Overview
Maddox Drive-Isolation Transformers are designed to meet the rugged demands of both AC and DC variable speed drives and provide the required voltage change.
The separate windings provide electrical isolation between the incoming power and the SCR or VFD load. The windings are designed to withstand overcurrent at 150% of the rated load for 60 seconds or 200% of the rated load for 30 seconds, as well as minor harmonic noise at or below K-Factor 4. Standard duty cycle is one start every two hours.
Drive Isolation Transformers are sized to match standard motor horsepower and voltage ratings.
Standard sizes range from 5 to 600 HP in six standard voltages.
Primary Voltage: 208 D
Secondary Voltage: 480 Y 277
Transformer Specifications:
- 60 Hz Frequency
- 150°C Temperature Rise
- 220°C Insulation Class
- Primary Adjustment Taps 1 above, 1 below in 5% increments
- Electrostatically Shielded
- High Efficiency Aluminum Windings
- Vacuum pressure Impregnated Windings
- DOE Exempt
- Lugs included up to 75 kVA
Transformer may appear different than pictured.
Size Guide
| kVA | Amps at 208v | Amps at 480v | Startup (low) | Startup (high) |
| 11 | 31 | 13 | 53 | 79 |
| 14 | 39 | 17 | 67 | 101 |
| 20 | 56 | 24 | 96 | 144 |
| 27 | 75 | 32 | 130 | 195 |
| 34 | 94 | 41 | 164 | 245 |
| 40 | 111 | 48 | 192 | 289 |
| 51 | 142 | 61 | 245 | 368 |
| 63 | 175 | 76 | 303 | 455 |
| 75 | 208 | 90 | 361 | 541 |
kVA Sizing Recommendation: At least 20% above the rated horsepower on the motor.
Dimensions & Weights
| kVA | Dimensions (HxWxD) | Weight (lbs) |
| 11 | 21.5"x19.38"x20.2" | 150 |
| 14 | 21.5"x19.38"x20.2" | 180 |
| 20 | 28.75"x23.9"x25" | 225 |
| 27 | 28.75"x23.9"x25" | 280 |
| 34 | 28.75"x23.9"x25" | 305 |
| 40 | 28.75"x23.9"x25" | 315 |
| 51 | 28.75"x23.9"x25" | 370 |
| 63 | 38"x26"x21" | 510 |
| 75 | 38"x26"x21" | 570 |
Approximate Enclosure Dimensions & Weights
Shipping rates vary, but are generally 10% of the total purchase price.
Transformers deliver in 5-7 business days.
Read more here: Shipping Policy
Ordered the wrong unit, or not sure if a product is right for you? Our web store exchange policy has you covered! We’ll send you a replacement transformer, all you pay for is shipping, plus the difference in unit price. Our policy lasts 30 days. If 30 days have gone by since your purchase, we cannot offer you a refund or exchange, but we still may be interested in buying the unit back. Proof of purchase is required to process a return or exchange.
Read more here: Return and Refund Policy
Buy with confidence. All new and used Maddox transformers are tested and come with a full 5 year warranty against defects. If you experience any problems just give us a call and receive a replacement, free of charge. We'll even pay the shipping!
Read more here: Warranty, Terms and Conditions
Reviews from our customers:
“I spoke with Josh Long and he was the most knowledgeable sales rep on transformers I had the pleasure of speaking with during my 2 month long ordeal to find a very specific transformer for my machine from overseas. I really appreciate his expertise on the matter and I look forward to working Josh again.”
Hien Tran“I love this company. I'm an electrical contractor and I use them for all my transformer needs and recommend them wherever I can. Josh Long and Chris Stouffer always return my calls and answer my emails. They provide a great, personalized service. It's nice to go straight to the source to buy rather than going through an electrical supply house or another middle man.”
Naomi Doire“Your service and response was impeccable. The equipment quality is excellent. It was a pleasure to work with Jeremiah. He was fantastic, sent me all the drawings and paperwork superfast. Can't wait to need another transformer. Thank you very much.”
Elliott Foy