HVAC - Heat Sequencer
Heat Sequencer Overview
Introduction to Heat Sequencers
- Robert Curry introduces the heat sequencer, a crucial component in air handler applications that controls the indoor blower motor and electric heat strips.
- The device is described as simple yet powerful, emphasizing its reliability in operation.
Functionality of Heat Sequencers
- The heat sequencer features multiple terminals for connections; wires can be connected to operate both relays effectively.
- Power is applied from a disconnect box to the relay, which remains inactive until low voltage power activates it, moving a plunger that turns on either electric heat or the motor.
Common Issues and Troubleshooting
- A typical failure mode involves the sequencer not applying power; checking for 24 volts at the terminals is recommended as an initial troubleshooting step.
- The sequencing process includes staging events where electric heat activates before the blower, preventing cold air from being blown through ducts initially.
Configuration Variations
- Heat sequencers come in various configurations (single or double stack), but they all function similarly regardless of their design.