When you're shopping relays, contactors, and industrial switches, two definite purpose contactors can look identical until you check the coil. Both of these Shopcorp units are 40A, 2-pole, normally open AC contactors that are UL Listed and rated for 40A inductive/motor loads along with 50A resistive loads. The important difference is the coil voltage: one is built for 110/120VAC control power and the other for 24VAC control power. That one spec determines which contactor will pull in when your control signal arrives. So the coil voltage is the deciding factor.
Quick Verdict
The 110/120VAC coil version is the straightforward match for line-voltage control circuits. The 24VAC coil version is the match for low-voltage control circuits powered through a 24VAC control source. Apart from the coil, the specs shown below are shared between the two. The decision is about control voltage, not contactor capacity.
Comparison at a Glance
| Spec | 110/120VAC Coil | 24VAC Coil |
|---|---|---|
| Listed price | USD 22.99 | USD 22.99 |
| Coil voltage | 110/120 V | 24 V |
| Current rating | 40 A | 40 A |
| Resistive rating | 50 A | 50 A |
| Pole configuration | 2-Pole NO | 2-Pole NO |
| Mounting style | Panel mount | Panel mount |
| Country of Origin | China | United States |
Where Each Product Wins
AC Contactor 40 Amp 50 RES 2 Pole 110/120VAC Coil wins when your control circuit is already powered at 110/120VAC. It is the direct replacement for a contactor that operates from line-voltage control power.
AC Contactor 40 Amp 50 RES 2 Pole 24VAC Coil wins when your control circuit is powered by 24VAC. It is the right match for low-voltage control systems powered at 24VAC.
Product Notes
#### AC Contactor 40 Amp 50 RES 2 Pole 110/120VAC Coil - Definite Purpose UL Listed
Choose this one when your control side is line voltage. Its 110/120VAC coil matches a standard 110/120VAC control circuit, and the unit is UL Listed as a definite purpose contactor. It is suited for HVAC, refrigeration, lighting, and heat pump applications. The AC-1 rating covers resistance furnaces, incandescent lamps, and electric heaters, while the AC-3 rating covers air conditioners, compressors, and fans. The limitation is fit: if your control circuit provides 24VAC, this coil will not be the one. For a line-voltage panel, this is the version that matches. Select it when your control wiring is line-voltage.
#### AC Contactor 40 Amp 50 RES 2 Pole 24VAC Coil - Definite Purpose UL Listed
Go this route when the control voltage is 24VAC. The 24VAC coil matches a low-voltage control circuit, and its listed Country of Origin is the United States, while the other version lists China. Like the other version, it is suited for HVAC, refrigeration, lighting, and heat pump duties, and it carries AC-1 and AC-3 ratings for resistive heating/lighting and motor or compressor loads. The limitation is the coil spec in reverse: a 110/120VAC control circuit will not drive this coil. So this version is for panels that already run on 24VAC control power. If your control system operates at 24VAC, this is the unit to use.
Final Choice by Use Case
Line-voltage control circuit? Choose the 110/120VAC coil version. Low-voltage 24VAC control circuit? Choose the 24VAC coil version. Both share the same contactor specifications, so matching the coil to your control power is the entire decision.
