5-2-1 Compressor Saver

The 5-2-1 Compressor Saver is a hard start kit produced by CPS Products, a company that has spent five decades designing tools and instruments for HVAC and refrigeration technicians.

Founded in 1975 and headquartered in Miramar, Florida, CPS Products built its reputation on refrigerant leak detectors, vacuum pumps, recovery equipment, and gauges before extending into compressor protection devices like the 5-2-1 line.

Product Lines

The 5-2-1 Compressor Saver lineup is organized by system tonnage, with kits sized for smaller residential systems up through larger commercial units, so technicians can match the kit to the compressor they are servicing rather than relying on a single universal size.

Each kit combines a multi-layer start capacitor with a current-sensing switch designed to give the compressor extra torque during startup, then disengage once the compressor reaches running speed.

Why Contractors Specify 5-2-1 Compressor Saver

HVAC technicians turn to hard start kits when a compressor struggles to start under load, particularly in older systems, hard-wired installations without soft-start electronics, or units running on long line sets and marginal voltage.

The 5-2-1 method has been reviewed and approved by major compressor manufacturers, giving technicians a documented basis for installing the device without voiding compressor warranties. Reducing start time and inrush current also eases strain on electrical components upstream of the compressor, which technicians weigh when diagnosing systems with recurring breaker trips or contactor wear.

How to Choose 5-2-1 Compressor Saver Products

Sizing starts with matching the kit to the tonnage of the system being serviced, since an undersized kit will not deliver enough starting assistance and an oversized one adds unnecessary cost to the repair.

Technicians troubleshooting hard-starting compressors should confirm the underlying cause, checking line voltage, contactor condition, and refrigerant charge, since a hard start kit assists a marginal start but does not correct an electrical fault or a charge problem. Voltage compatibility also matters, since kits are built for specific voltage ranges and should be matched to the system's supply voltage before installation.

Frequently Asked Questions

What does a 5-2-1 Compressor Saver hard start kit actually do?

It combines a multi-layer start capacitor with a current-sensing switch to give a compressor extra torque during startup, cutting start time and reducing inrush current before disengaging once the compressor reaches full speed.

How is the correct 5-2-1 kit size determined for a job?

Kits are sized by system tonnage, so matching the kit to the tonnage rating of the compressor being serviced is the starting point for selecting the correct unit.

Will a hard start kit fix a compressor that trips the breaker on startup?

A hard start kit can reduce inrush current and ease starting strain, but it will not resolve underlying issues such as low line voltage, a failing contactor, or improper refrigerant charge, which should be diagnosed separately.

Is the 5-2-1 Compressor Saver approved by compressor manufacturers?

The 5-2-1 method has been reviewed and approved by major compressor manufacturers, giving technicians a documented basis for installation without concerns about voiding compressor warranties.

Can a 5-2-1 kit be installed on any voltage system?

Kits are built for specific voltage ranges, so confirming the system's supply voltage against the kit's rated voltage range is necessary before installation.