MARS 19005 Potential Relay

The MARS 19005 Potential Relay is a heavy-duty 395V 66 potential relay engineered for precise single-phase motor starting in high-demand refrigeration and air conditioning systems. This component is identical to 90-66 and serves as a universal field replacement for thousands of OEM models, including GE 3ARR3-3U, 3V, and 3AT groups. Designed for reliability, the MARS 66 features a 35-amp contact rating at 277 VAC and a non-positional design, allowing for flexible mounting without affecting calibration. The unit provides a continuous coil voltage of 395V, with a pick-up range of 215 to 225 volts and a maximum drop-out of 120 volts. For contractors, the included universal break-off bracket and screw terminals (convertible via QC-6 kits) ensure a rapid, secure install. Whether you are troubleshooting compressor start assist issues or performing a routine HVAC potential relay replacement, this rugged component ensures the starting capacitor is dropped out at the exact moment the motor reaches optimal speed, protecting windings from excessive heat.

• OEM Cross-Compatibility: Directly replaces thousands of original equipment relays, including those from White-Rodgers, Packard, and GE.
• Non-Positional Operation: Precision-calibrated internal components allow the relay to be mounted in any orientation without performance drift.
• High Power Capacity: Rated for up to 35 amps, maintaining durability during high-torque startup cycles.
• Fast Field Integration: Break-off mounting brackets and clear wiring diagrams streamline the installation process on tight service calls.
• UL and CSA Listed: Meets rigorous industry safety standards for HVACR motor controls.

What are the wiring terminal designations for this relay?
The MARS 19005 uses standard industry numbering: Terminals 1 and 2 are for the start capacitor and starting winding, while Terminal 5 is the common side of the coil. Terminals 4 and 6 serve as anchor points for additional wiring as needed.

Can this relay replace a 90-66 model?
Yes, the MARS 19005 is technically equivalent and identical to 90-66, sharing the same electrical specifications and pickup/dropout thresholds.

When should I replace a potential relay instead of just the capacitor?
If the compressor fails to start but the capacitor tests within tolerance, or if the start capacitor is consistently blowing, the potential relay contacts may be welded or the coil failed. Always check the continuous coil voltage during operation.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.