Why Use a Start Assist Device On Your Compressor

  April 1, 2016      Jeff Rosenblum


Many times we receive questions as to why someone would want to install a start capacitor (5-2-1). There are several reasons why this would be beneficial. As a compressor ages it may become more difficult to start. The windings may be ne, and once it’s running it operates properly, however, sometimes it just doesn’t want to get going. Oftentimes, adding a start assist device can give the compressor a bit of a boost.

This same theory applies to new units where the compressor may have a di cult time starting. Many times technicians think the compressor needs replaced, so why would a new unit need a start cap? Oftentimes, with long line sets or TXV’s, a start cap is recommended, and newer compressors are built with closer tolerances. As we try to manufacture units with more efficiency and less chance of bypass gas (which robs efficiency) we end up making the compressor tighter. Just because a new compressor doesn’t start, doesn’t mean it’s bad. Sometimes a little boost is all it needs. Just like us, we need co ee to get us going, a compressor needs a start assist to “wake up”.

Some of the benefits of a start assist are less wear and tear on capacitors, less light dimming on startup, and reducing the chance of a breaker tripping on start up. Before you condemn a compressor, try a Start assist (5-2-1).

I was told back in the day that start assists are only for failing units. This is not true. They can be used on new and existing units without problem. I have used them successfully for years. So before you say a seized compressor must be replaced, try a 5-2-1. You may be surprised by the results.

Jeff Rosenblum 
Technical Support
17 Years Industry Experience
Cell (330) 962-2491
[email protected]