Understanding the function of an HVAC disconnect switch is important for anyone considering purchasing one for their home. However, did you know that certain electrical codes have required this safety device to be installed in homes since the mid-1970s? The purpose of an HVAC disconnect switch is to prevent electrical fires by shutting down the power to the air conditioning system. Hence, this blog will give you a basic overview of what an HVAC disconnect switch is and what it does.
What Is an HVAC Disconnect Switch?
Working on HVAC equipment usually requires the technician to perform a diagnostic check-up of your unit or complete repairs. Then, to ensure they can work safely, they will shut down electrical power to your unit using either a disconnect switch or an isolator. Working on an AC unit can be dangerous, so having a disconnect switch within sight is important. This way, anyone who does not know that the technician is working on the unit will not accidentally turn on the power and cause damage or injury.
Does an AC Unit Need a Disconnect Switch?
All HVAC systems must have a readily accessible way to disconnect from electrical power, per the National Electrical Code. That is usually accomplished via a disconnect switch, allowing easy removal of all power to the device. A disconnect switch is imperative during maintenance and when repairing your HVAC system to prevent electrical issues.
Fused Disconnect vs. Non-fused Disconnect
HVAC equipment must have protection, so they do not get damaged beyond repair. And soon, it will be necessary for your own safety. For example, air conditioners — also true of many HVAC units — can be protected by disconnect switches.
There are two types of disconnect switches for HVAC: fused and non-fused (non-fusible). The former protects against overcurrents and short circuits, whereas the latter only protects from overcurrents.
When shopping for a disconnect switch, ensure it is compatible with your HVAC model. First, read the owner’s manuals and consult a professional HVAC technician to see what capacity and features your unit supports. Then, verify that the model you are shopping for fits those needs. For instance, most units can shield against power surges and outages, but some will not. Therefore, make sure your selection has this powerful function.
Inspecting a Disconnect Switch
Your disconnect switch is essential to keeping your HVAC system safe and working properly. To keep yours up to par, there are a few steps you can take.
First, unplug the disconnect switch. Then, shut off the power supply to the HVAC unit at the breaker box. After that, you can proceed with the inspection. Just keep an eye out for the following:
- Switch covers should be tightly closed and free of cracks or holes. The handlebar should move freely on all its tracks without sticking in any direction.
- Check the main disconnect or panel for rust or corrosion. Look for any signs of overheating.
- Verify the panel board’s rating and size to ensure they are appropriate.
- Look to see whether the disconnect might be positioned incorrectly.
- Search for any signs of damage both inside and outside the panel box.
- Make sure the wiring is in perfect condition.
- Keep an eye out for water leaks or water entering the box.
Need help with your disconnect switch? Pioneers Heating and Air is a full-service HVAC company providing all types of expert service and air conditioning repair. Whether you need a new installation or AC maintenance or are experiencing system problems, we can help! We serve homes and small businesses in and around Pasadena and Altadena, CA, from routine repairs to full system replacements. We are a BBB-rated contractor, so you can be sure you are getting the best service possible. Plus, our team of HVAC installers is experienced and highly trained with up-to-date knowledge that they apply in every job we do. So please do not hesitate to call us for your HVAC needs.