Tech Tip



While our customers are wholesalers, Packard knows that you, the contractor, have a choice. You are often presented with many buying options, and being well-informed about your purchase can help make your job easier and more successful.  Our Tech Tips are also very helpful for our wholesalers as we present product information that can help as contractors have questions.

This is why we have dedicated a section of our site for contractors and wholesalers. In this section, you will find helpful product tips, tools and some clips from our training classes. We’ve also provided a distributor locator so you can find the nearest wholesaler who can give you access to Packard products.

I’ve installed a surge protector on the disconnect of the condenser but the LED doesn’t light, indicating that it’s not operating.  I’ve double checked connections and they appear OK.  What’s up?

With all of the electronics that we now have in our HVAC/R systems, they can be very sensitive to power supply variations and surges.  This can be a major reason for failure in applications.  To protect against this, Surge Protective Devices (SPDs), or surge protectors, have become very prevalent. 

Surge Protective Devices

These are very easy to install, however, there are some key things to keep in mind.

They are connected directly to the disconnect or breaker panel.  The most common installation mistake is the connection to ground.  Not that the ground lead is not connected to the ground buss, but that the ground buss is not a proper ground.

There should only be one, “common ground per system to eliminate the possibility of a differential in ground potentials.”  Once that has been verified, the ground resistance must be measured.  It cannot be assumed that it is a proper ground.  The maximum ground resistance should be 25 Ohms.  The optimum ground would measure 5 Ohms or less.  Exceeding this resistance will result in improper installation, and the LED will fail to light on the SPD.  This could result in no surge protection.

Proper grounding is not only a safety concern, but it is also a critical component for correct performance of many of our electronic controls and devices, including surge protective devices.