Quick Take
Matching the transformer's output voltage to your control devices is the first decision. The four units here cover the outputs most industrial panels use: 24V for low-voltage relay logic, 115V for many older control circuits, and 120V for standard motor-control panels. Listed prices run from $44.99 to $175.00, so the choice is mostly about capacity and voltage, not just budget. If you are replacing a failed unit, check the original secondary voltage before ordering.
Listed Price Comparison
| Product | Listed price | Price bar |
|---|---|---|
| ACME TA-2-81321 Industrial Control Transformer | $44.99 | |
| Hammond PT50MLI - BULK Industrial Control Transformer | $44.99 | |
| Emerson SolaHD E150 Industrial Control Transformer | $79.95 | |
| Square D 9070TF100D1 Industrial Control Transformer | $175.00 |
The bar length gives a quick visual: the two 50VA units sit at the low end, the 150VA Emerson sits in the middle, and the Square D sits at the high end.
Decision Matrix
| If you need... | Choose... |
|---|---|
| A 24V secondary for relay or logic circuits | ACME TA-2-81321 |
| A 115V secondary from a 208/230/460V primary | Hammond PT50MLI - BULK |
| More capacity with a 120V-class secondary | Emerson SolaHD E150 |
| A new Square D replacement with MPN 9070TF100D1 | Square D 9070TF100D1 |
Product Notes
ACME TA-2-81321 Industrial Control Transformer
The ACME TA-2-81321 is aimed squarely at a 24V control circuit. It carries a 50VA rating, accepts a 208/480V primary, and outputs 24V, which lines up with control relays, timers, and indicator lamps. The unit is in new open-box condition. The limitation is on the output side: a 24V secondary will not directly power 115V or 120V control devices, so keep this unit on panels that are all 24V. If your primary supply is 208V or 480V and the load is small, the ACME is the practical option for a clean low-voltage circuit.
Hammond PT50MLI - BULK Industrial Control Transformer
The Hammond PT50MLI is the option to choose when your control circuit runs on 115V and your primary side could be 208V, 230V, or 460V. The 50VA rating is the same as the ACME, but the secondary is 115V instead of 24V, so it suits relay panels and contactor coils that are not low-voltage. The unit is used, which is the main trade-off. If you need a straightforward 208/230/460V-to-115V transformer and your load stays within 50VA, this Hammond covers the job without extra converter hardware.
NEW Emerson SolaHD E150 Industrial Control Transformer
The Emerson SolaHD E150 takes the next step up in capacity. It is rated at 150VA, with a 240x480V primary and a 120V secondary in the title; the same model also connects to 220/230/440V primaries and 110/115V secondaries. The epoxy-encapsulated construction is suited to industrial control panels. The trade-off is on low-voltage circuits: this unit outputs 120V-class voltage, not 24V, so it will not replace the ACME for 24V logic. If your loads are larger and you want one transformer that can work with a 240V or 480V feed, the E150 is the clear match.
Square D 9070TF100D1 Industrial Control Transformer
The Square D 9070TF100D1 is for projects where the part number is already specified. It is new, with the Square D industrial control transformer designation, and the MPN gives you a clear part number to match. Working against it is the cost: this is the highest listed price in the group, so it makes sense when you need the Square D part, not when you are just comparing control transformers on price. If your specification already calls for 9070TF100D1, this new unit is the one to order.
Final Recommendation by Use Case
Pick the ACME TA-2-81321 for a 24V control panel where the load is a few relays and pilot lights. Pick the Hammond PT50MLI when you need 115V from a 208/230/460V feed. Pick the Emerson SolaHD E150 for a 120V-class circuit that wants 150VA of headroom. Pick the Square D 9070TF100D1 only when the spec already calls for that exact model. With the secondary voltage matched first, the right transformer becomes much easier to identify.
