The 370 VAC rating provides a necessary safety margin against the back-EMF generated by the motor windings

Because R-410A is a blend

reducing diagnostic callbacks during critical cooling cycles

specifically those requiring the 100208545 or TST20015 part numbers

it maintains stable regulation from full flow down to pilot flow

Carrier HH19ZH175 Limit Switch 320735-701 The 370 VAC rating providesAs a field tech, you know that a failed safety circuit is the fastest way to a no heat call. The Carrier HH19ZH175 is a critical furnace high limit switch designed to protect the heat exchanger from thermal stress. This 175F limit switch features a normally closed (CO) configuration, meaning it stays shut during standard operation and opens the circuit at its 175 degree setpoint to kill the gas valve or heating elements. This specific HH19ZH175