Protective Controls In HVAC Units?

In any HVAC unit you buy, there's a system that's in place to protect the unit itself. Many HVAC manufacturers, in fact, always make sure to provide sometimes optional controls that help protect the HVAC units that they may produce.

Believe it or not, these protective controls were once standardized and included in practically all units produced by HVAC manufacturers. Nowadays, these protective controls are mostly optional for the purpose of reducing production costs. While they're optional now, they're still offered for people that do want to protect their large appliances.

One of the most common types of 'optional control' is the pressure control switch. The pressure control switch is a component found in appliances and other machines that helps protect the system from succumbing to the presence of excessive high or low pressure.

The switch itself is designed to close a certain electrical contact when it reads a certain pressure threshold. Switches can be designed to come into with its electrical or mechanical contact when the pressure rises or falls.

HVAC units and the pressure switch

Many HVAC units are built with some kind of HVAC switch, mainly to protect the unit in the case of it reaching a certain high or low pressure threshold. In many commercial and consumer HVAC devices, HVAC switch are available as both high and low pressure switch controls.

High switch controls act as protective devices for refrigerator units, mainly for the refrigerator's compressor and actual refrigeration unit. These HVAC pressure switches help monitor the refrigerator's system for several things. The monitoring system usually checks for inoperative units like an inoperative outdoor motor or a restricted dirty condenser coil. Some HVAC pressure switch that monitor high pressure in a refrigerator system check for both.

A HVAC pressure switch that checks for low pressure in an appliance are designed to help monitor and protect the efficiency of the refrigerator's cooling system. They help check for a loss of refrigerant charge, in addition to helping stop the evaporator coil from freezing, usually due to low coil airflow or a dirty filter.

Why the HVAC switch works

The refrigerator example that was mentioned in the last section was a common example of how the HVAC switch remains an important component in any type of large appliance or machine that requires certain operational assistance. Its importance to any HVAC unit is best explained by how these pressure switches work.

A HVAC pressure switch works because it's designed to shut down entire units if something 'goes wrong.' When the HVAC unit detects something wrong, the HVAC switch will cause the entire system to shut down in response. Whether it shuts down in response to high or low pressure, it's the responsibility of the operator to reset the controls to continue using the unit.

Most HVAC pressure switches can be reset from inside the unit, while others have to be reset via components like a thermostat by turning on and off its sub-base system switch.

I write on many diffrent topics. Follow me to read all great articles.