When you need to switch a heavy AC motor, a compressor, or a bank of control circuits, the relays contactors industrial switches aisle offers two very different tools. A contactor is built to carry heavy inrush loads, while an industrial control relay is built to route multiple control signals reliably. The two products here make that contrast clear: a new 1-pole contactor at the lower end of the price range and a used Square D industrial control relay with an expandable base at the higher end.
Quick verdict
If you need a drop-in replacement for a failed contactor in an AC compressor or condenser, the 1 Pole 40A 24V AC Contactor is the straightforward choice. It is new, and its direct-replacement design removes the need for wiring changes. If you are building or servicing an industrial control panel and need multiple relay contacts, the Square D 8501 X080 offers an expandable base and heavy-duty industrial build.
At a glance
| Feature | 1 Pole 40A 24V AC Contactor | Square D 8501 X080 Relay |
|---|---|---|
| Price | $19.66 | $27.99 |
| Role | AC motor/compressor contactor | Heavy-duty industrial control relay |
| Contact setup | 1 pole, 40A, 24 VAC coil | 8-pole base expandable to 12; 8 N.C. contacts |
| Condition | New | Used |
| Best suited for | Direct replacement in AC condenser units | Multi-circuit industrial control panels |
Where each product wins
The contactor wins on simplicity and new condition. This single-pole contactor is designed for one job: switching an AC motor or compressor load. It is sold as a new unit, so there is no wear to inspect before installation. The copper terminal contacts and flame-retardant shell add practical durability for HVAC service.
The relay wins on contact density and expandability. The Square D 8501 X080 comes with eight normally closed contacts on an 8-pole base that expands up to 12 poles. That makes it a strong fit for interlock and fail-safe circuits requiring multiple closed paths in the de-energized state. The A600/P600 NEMA contact ratings support industrial control workloads.
Product notes
1 Pole 40A 24V AC Contactor
This contactor is a purpose-built replacement for AC compressor and condenser contactors. It is a 1-pole unit with a 40A rating and a 24 VAC coil, listed for 50/60 Hz operation. Copper terminal contacts and a pure copper coil are part of its construction, along with a flame-retardant shell. The direct-replacement design is the strongest reason to choose it: no wiring or adapter changes are required, saving time during a service call. The limitation is its narrow role. With just one pole and a fixed 40A/24V coil, it is not a general-purpose control relay. If your application needs multiple contacts or a different coil voltage, this contactor won't stretch to fit.
Square D 8501 X080 Industrial Control Relay
This relay is an industrial control workhorse. Its main strength is the 8-pole base that expands up to 12 poles, all with normally closed contacts-a practical layout for fail-safe circuits. The 10A thermal current rating and 600V AC maximum voltage rating are solid for control-circuit service. It is a pre-owned unit that has been thoroughly tested and is fully functional, with minor cosmetic wear as the trade-off. That used condition is the main limitation: you get the industrial build and expandability, but not a factory-fresh finish. If a scratch-free unit matters, this relay is not the right pick.
Final choice by use case
For a quick replacement of a failed AC contactor in a compressor or condenser, the contactor is the right pick. It is the lower-priced option at $19.66.
For a control cabinet that needs several relay contacts in a compact package, the Square D 8501 X080 is the better fit. It offers expandable contact capacity, heavy-duty NEMA construction, and a thoroughly tested used unit at $27.99.
