HVAC Controls 26408-23 Practice Test

Staggering the startup of electric heating elements to limit the surge current is done by a heat sequencer. In a multi-element heater, several elements could try to energize at once, which would draw a large inrush and risk tripping the breaker or overloading the circuit. The heat sequencer energizes the elements one after another, or in small groups, with short delays between them. This keeps the initial current well within what the wiring and disconnects can safely handle and helps maintain steady voltage during startup. The thermostat simply switches the system on or off based on temperature, without coordinating multiple elements. A short-cycle timer is used to prevent rapid on/off cycling, not to stagger element startup. A blower relay controls the blower motor, not the sequence of heater element energization.