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Small rectangular relay with metal terminals and plastic housing

Value Brand

Value Brand Potential Relay 35A 500V Coil

SKU CH-7KH4-B8QBA

A 35-amp potential relay with a 500-volt coil for HVAC motor-start switching

  • Reliable switching up to 35 amps contact rating
  • Precise activation between 260 and 275 volts AC
  • Safe dropout below 135 volts AC
  • Compact size fits tight HVAC enclosures
  • Prop 65 chemical warning applies to this component

Relay for HVAC motor control

This potential relay is designed for HVAC systems that need reliable motor-start switching. It carries a 35 A contact rating and operates from a 500 V AC coil, making it suitable for compressors and fan motors in residential or light commercial equipment.

Pick-up and drop-out thresholds

The relay picks up between 260 V and 275 V AC and drops out at 135 V AC maximum, providing a defined voltage window for motor-start engagement. Its mechanical SPST construction has no voltage-sensing circuitry, so operation depends solely on coil voltage reaching the specified range.

Replaces failed potential relays

Use this unit when an existing potential relay no longer pulls in at the correct voltage or sticks in the closed position. It is not intended for applications that require adjustable pick-up settings, time-delay functions or voltage-sensing logic.

How it compares

Measured against everything we stock in Heating & Cooling Controllers, at today’s prices. Recalculated every night.

Price $12.99
Cheaper than about 84% of the 1,762 comparable items (median $45.99).

Specifications

Product
Brand nameZORO SELECT

Questions about this item

How is the 500 V AC coil wired during installation, and what step do people get wrong?

Connect the coil across the motor start winding so it sees 500 V AC; the common mistake is wiring it to the run winding instead, which prevents the relay from picking up at the required 260–275 V AC.

What maintenance or replacement will this 35 A SPST potential relay need later?

The mechanical contacts are rated for 35 A; plan to replace the relay when contact erosion causes voltage drop or the coil no longer drops out cleanly at 135 V AC.

What limit appears first when this relay runs continuously at its 35 A rating?

Contact heating at the 35 A rating is the first limit; sustained current near that level accelerates wear and can prevent reliable drop-out at 135 V AC.

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