When a machine's control circuit needs the right voltage, an industrial control transformer is the component that gets you there. These units take line voltage and convert it to a lower, safer level for relays, contactors, and timers. But they're far from one-size-fits-all: Some listings emphasize frequency, some call out step-down capability, and others just give you the model and price. This guide looks at four real listings-from Schneider Electric, Square D, Hammond Power Solutions, and Eaton/Cutler-Hammer-to help you decide which one belongs in your panel.
What you're choosing between
- Schneider Electric 9070T500D3 - $150.00 · Open-box, AC-to-AC conversion
- Square D / Schneider Electric 9070T500D1 - $179.97 · Open-box, step-down conversion
- HPS PH100MLI - $80.00 · New, 100-VA rating
- Eaton / Cutler-Hammer C0100E3A - $79.99 · New in box, made in the US
The price spread is straightforward: $79.99 on the low end, $179.97 on the high end, about a $100 difference between the top and bottom of the range.
Listed price comparison
| Product | Listed price | Price bar | Condition | Standout feature |
|---|---|---|---|---|
| Schneider Electric 9070T500D3 | USD 150.00 | New - Open box | 50-60 Hz operation | |
| Square D / Schneider Electric 9070T500D1 | USD 179.97 | New - Open box | Step-down conversion | |
| HPS PH100MLI | USD 80.00 | New | 100-VA rating | |
| Eaton / Cutler-Hammer C0100E3A | USD 79.99 | New in box | Made in United States |
The two open-box Schneider Electric-family transformers are the most expensive here, while the two lower-priced listings are new. If you're trying to keep the budget in the $80 range, both the HPS and Eaton sit right around that mark.
Decision matrix
| Product | Best for | Why |
|---|---|---|
| Schneider Electric 9070T500D3 | AC-to-AC conversions | A mid-priced open-box transformer from Schneider Electric |
| Square D / Schneider Electric 9070T500D1 | Step-down needs | The only listing that spells out step-down conversion and a 24V secondary |
| HPS PH100MLI | A new 100-VA unit | New condition plus an explicit VA rating for $80 |
| Eaton / Cutler-Hammer C0100E3A | Budget replacements | Lowest listed price, new in box, US origin |
Product notes
Schneider Electric Industrial Control Transformer - 9070T500D3
This Schneider Electric listing is a black, open-box transformer made in the United States. It's built for AC-to-AC conversion, which makes it a solid fit for control panels that need straightforward voltage conversion. Choose it if you value a Schneider Electric unit and are comfortable with an open-box condition. The $150.00 price is the second-highest in this group, and since it's open-box rather than new, you're trading a little factory-fresh status for a mid-priced entry. Still, for a control transformer from a major manufacturer, this one covers the basics cleanly.
Square D / Schneider Electric 9070T500D1
The Square D / Schneider Electric 9070T500D1 is the top-priced listing at $179.97. It shares the open-box condition and includes a step-down conversion function and a secondary voltage rating of 24V DC. If your circuit explicitly needs a step-down transformer, this listing gives you that detail up front. The drawback is the cost: it's $100 more than the Eaton and HPS listings. For that price, you get the step-down specification and the Square D brand, but you'll still be receiving an open-box unit.
HPS PH100MLI Industrial Control Transformer 100-VA
The Hammond Power Solutions PH100MLI is listed at $80.00 and is brand new. The title alone gives you the key spec: 100 VA. If you're replacing a transformer with a known volt-amp rating and want a fresh, unopened unit, this is the straightforward choice. The listing text is brief: it includes a note to send a message if you have questions, and the main data point is the VA rating. It sits at the same price point as the Eaton, but with the explicit VA number to anchor your decision.
Eaton / Cutler-Hammer C0100E3A Industrial Control Transformer (New in Box)
The Eaton / Cutler-Hammer C0100E3A is the lowest-priced option in this comparison at $79.99. It's listed as new in box, made in the United States, and belongs to the E3 series. If you want to keep the procurement cost as low as possible and prefer a factory-sealed unit, this listing is the one to start with. The listing focuses on brand, model, condition, and origin, making the price the main differentiator. That means you'll be relying on the model number to understand its capacity, rather than a feature list.
Final recommendation by use case
- For the tightest budget and a new unit in the US: the Eaton / Cutler-Hammer C0100E3A at $79.99 is your low-cost entry.
- For a new unit with a specified VA rating: the HPS PH100MLI at $80.00 adds a clear 100-VA rating.
- For 50/60 Hz operation and open-box value: the Schneider Electric 9070T500D3 at $150.00 gives you frequency flexibility.
- For step-down conversion plus the Square D brand: the Square D / Schneider Electric 9070T500D1 at $179.97 is the most feature-rich listing here.
No single transformer fits every panel, but with the price and feature details above, you can match the listing to your control circuit's requirements.
