The fan coil unit (FCU) is a device consisting of a fan and a heating or cooling element called a coil. Room air flows over the coils, which heats or cools the air depending on the type of replacing condo fan coil and then pushes the air back into the chamber.
As shown in the fan coil unit diagram, the cooling coil is used to cool an area without being connected to line operation. Hot air enters the device on the left and moves through the cooling element. Cool air is expelled on the right side. In fan coil units using a heating coil, the direction of heating is reversed, with hot air expelled from the fan coil unit.
With a constant volume fan motor, about 60% of the energy consumed is used to drive the air, while 40% or less of the energy consumed is used to rotate the motor. If the fan motor is mechanically damaged or the belt breaks, the motor current will drop by about 60%.
The power switch monitors the condition of the fan motor by reading the current in the wires that power the motor. Mechanical damage to the motor causes a decrease in current, which is immediately detected by the power switch, which sends a signal to the controller. Power switches offer the most reliable and cost-effective way to monitor positive flow evidence for fan coil units.
The differential pressure switch monitors the condition of the fan motor by sensing the pressure difference between the inlet and outlet sides of the fan.