---
product_id: 2331469
title: "SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque"
brand: "sealed unit parts co., inc."
price: "$U2195"
currency: UYU
in_stock: true
reviews_count: 12
category: "Supco"
url: https://www.desertcart.uy/products/2331469-supco-spp6-relay-capacitor-hard-start-kit-with-500-increase
store_origin: UY
region: Uruguay
---

# 500% boost starting torque Fits PSC A/C & heat pumps Easy 10-min pro install SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque

**Brand:** sealed unit parts co., inc.
**Price:** $U2195
**Availability:** ✅ In Stock

## Summary

> ⚡ Start Strong, Stay Cool — The Hard Start Kit That Means Business

## Quick Answers

- **What is this?** SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque by sealed unit parts co., inc.
- **How much does it cost?** $U2195 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.uy](https://www.desertcart.uy/products/2331469-supco-spp6-relay-capacitor-hard-start-kit-with-500-increase)

## Best For

- sealed unit parts co., inc. enthusiasts

## Why This Product

- Trusted sealed unit parts co., inc. brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Plug & Play for Pros:** Quick install designed for skilled hands—get back to comfort fast.
- • **Versatile Compatibility:** Engineered for permanent split capacitor single-phase A/C & heat pumps.
- • **Cost-Effective HVAC Upgrade:** Professional-grade performance without the $389 install fee.
- • **Power Up with 500% More Torque:** Supercharge your compressor start effortlessly.
- • **Silent Start, Smooth Operation:** Reduces startup noise and strain on your compressor motor.

## Overview

The SUPCO SPP6 Hard Start Kit delivers a powerful 500% increase in compressor starting torque, designed specifically for permanent split capacitor single-phase air conditioners and heat pumps. With an integrated relay to protect your compressor motor, this easy-to-install kit reduces startup noise and strain, ensuring smoother, more reliable operation. Ideal for residential and commercial PSC A/C units, it offers a cost-effective upgrade that outperforms pricier alternatives.

## Description

Relay/CAPACITOR hard start kit 500% incr starting torque,increased compressor starting torque. Designed for use on permanent split CAPACITOR single phase a/c and heat pump systems. Multiple use includes: room air conditioner units, residential or commercial psc AC units.. the country of origin is china.

Review: Straightforward Install for Skilled Persons - This was a 10 min install, but you need to savvy and comfortable working on electrical items, especially capacitors. There are You Tube videos that are constructive. After opening the nearby circuit breaker, opening up the electrical cover, grounding out the capacitor(s), and mounting/connecting the Hard Start kit, the kit performed as advertised. The AC compressor started up more easily and isn’t as loud at startup. This particular HS kit has an integrated Relay to disconnect its internal capacitor to prevent damage to the compressor motor after startup. Other comparable professional two wire or three wire HS kits cost about $150. My AC vendor offered to install their HS kit for $389,
Review: Worked for me - Bought this capacitor not expecting much - cause its so cheap. Did not take long to get it, thanks desertcart! Bought a cheapo Generator (All Power America APG3012 3,250 Watt 6.5 HP OHV 4-Cycle Gas Powered Portable Generator - search for it on desertcart ) - and found that it could not start my RV/AC without some hysterics - literally the generator started to walk across the driveway trying to rev up enough to start the compressor on the A/C. IT would eventually kick in, but I wanted a better solution. Took about 15 minutes to put this capacitor on my 2002 Dometic 13.5K BTU A/C. Which did have a starting capacitor - bout 1/2 the size of this thing. I just wired it in parallel as there were lugs to do so on the original starting capacitor. And sure enough! The A/C compressor started, the Generator surged just a bit under the strain, then returned to normal speed - I base this on how it sounds - dont have a A/C volt meter. But worked very very well. I've run this combo for several hours to test the capacitor and the generator - no real issues other than if i run the A/C i can’t run really any other high amp device such as a microwave, but hey I didn't want to lug around a really heavy generator for camping and having some A/C while in the desert is fantastic. I should mention, that the Generator can start the A/C when it’s first turned on, but when the system pressurizes - that’s when the generator could not re-start the compressor easily. Now if there is at least 45 second between compressor cycles, this capacitor makes the next start of the compressor pretty painless without much struggle by the generator. I was told by someone that works on A/Cs that when the system is pressurized the compressor takes more power to start. For what its worth.

## Features

- Relay/capacitor hard start kit 500% incr starting torque
- Increased compressor starting torque. Designed for use on permanent split capacitor single phase a/C and heat pump systems
- The country of origin is china

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0002YTLFE |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #31,212 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #92 in Industrial Electrical Capacitors |
| Customer Reviews | 4.6 4.6 out of 5 stars (1,954) |
| Date First Available | August 27, 2004 |
| Included Components | Electrical Replacement Parts^Electrical Replacement Parts^replacement-household-furnace-control-circuit-boards |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 4.8 ounces |
| Item model number | SPP6 |
| Manufacturer | SUPCO |
| Part Number | SPP6 |
| Power Source | AC |
| Product Dimensions | 6.5 x 7.25 x 6.5 inches |
| UPC | 687152031528 687152197361 |
| Voltage | 230 Volts |
| Warranty Description | Limited manufacturer's warranty (details not specified) |

## Product Details

- **Brand:** Sealed Unit Parts Co., Inc.
- **Material:** Aluminum
- **Mounting Type:** Panel Mount
- **Product Dimensions:** 6.5"W x 7.25"H
- **Shape:** Oval

## Images

![SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque - Image 1](https://m.media-amazon.com/images/I/71wgg5wU+zL.jpg)
![SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque - Image 2](https://m.media-amazon.com/images/I/7162p8bSyDL.jpg)
![SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque - Image 3](https://m.media-amazon.com/images/I/719JrXrxE5L.jpg)
![SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque - Image 4](https://m.media-amazon.com/images/I/71a8PcI2EgL.jpg)
![SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque - Image 5](https://m.media-amazon.com/images/I/31LvJXYzB6L.jpg)

## Questions & Answers

**Q: I live in Az.I need a hard start kit for a 30,000 btu 2.5 ton,which one do you recommend?**
A: The Supco uses a Positive Temperature Coefficient Relay (as stated on their website) not a Potential Relay. Not Good! Only use Hard Start Kits that use a true Potential Relay. The RectorSeal Kickstart (2 wire) and the 5-2-1 Compressor Saver (3 wire) hard start kits use a Potential Relay. I recommend the Kickstart (it uses 2 wires that connect to the Run Capacitor - HERM and COM). But the Compressor Saver is also good (3 wires with one connecting to the common / ground on the Contactor relay). They both work the same way - the Potential Relay detects the pickup voltage (back EMF). This causes the relay to disconnect the start capacitor when the compressor reaches about 75% speed (usually less than a second). Note: Supco does have hard start kits with a Mechanical Potential Relay (Models 3W1, 3W2, & 3W3) but they are not available on Amazon.

**Q: If there is an existing start capacitor, can you put this one in parallel with it or the run capacitor?**
A: This takes the place of the start capacitor. It gives an old compressor a "punch" as it starts and it immediately goes out of the start up circuit. They work! It is wired in parallel with the run capacitor, which stays in teh circuit so your compressor will run more efficiently..electrically speaking.

**Q: Can a hard start kit help an a/c compressor start when powered by a generator which more than satisfies the unit's FLA but is just shy of the LRA?**
A: Greetings,I use these for my rental apartment AC units they keep these old units running and starting easy!  They need to be checked every 2 year or so. If you are just shy of the  Locked Rotor Amperage; The amperage the motor draws when the voltage is first applied to the motor and the rotor has not started to turn. This amperage is usually up to 300% of the motors running amperage. Once the rotor starts to turn the motor generates a back EMF (electro motive force) that opposes the high inrush current. This back EMF drives the amperage down until the motor gets up to its rated speed at which time the motor amperage will be at its run amperage.   This device helps starting and should make you successful.  Make sure that your line voltage is being properly supplied during the high current peak that you have proper AWG for the load and length from your generator to  your compressor as it could be a voltage drop issue.Never the less a good part and should help.Best of LuckDarrell

**Q: Is this pretty easy to install?  Is it just removing two wires from the old capacitor and reattaching to the new hard start capacitor? Thanks.**
A: The hard start cap installs in parallel with the old cap. You connect one wire to the common and one wire to the herm terminals on the old cap.  This just gives the compressor an extra kick.  I would recommend that you get the 5-2-1 hard start kit instead.  I have tried both and the 5-2-1 works better.  Just search on Amazon for 5-2-1 hard start kit.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Straightforward Install for Skilled Persons
*by A***R on July 17, 2025*

This was a 10 min install, but you need to savvy and comfortable working on electrical items, especially capacitors. There are You Tube videos that are constructive. After opening the nearby circuit breaker, opening up the electrical cover, grounding out the capacitor(s), and mounting/connecting the Hard Start kit, the kit performed as advertised. The AC compressor started up more easily and isn’t as loud at startup. This particular HS kit has an integrated Relay to disconnect its internal capacitor to prevent damage to the compressor motor after startup. Other comparable professional two wire or three wire HS kits cost about $150. My AC vendor offered to install their HS kit for $389,

### ⭐⭐⭐⭐⭐ Worked for me
*by P***N on June 15, 2015*

Bought this capacitor not expecting much - cause its so cheap. Did not take long to get it, thanks Amazon! Bought a cheapo Generator (All Power America APG3012 3,250 Watt 6.5 HP OHV 4-Cycle Gas Powered Portable Generator - search for it on Amazon ) - and found that it could not start my RV/AC without some hysterics - literally the generator started to walk across the driveway trying to rev up enough to start the compressor on the A/C. IT would eventually kick in, but I wanted a better solution. Took about 15 minutes to put this capacitor on my 2002 Dometic 13.5K BTU A/C. Which did have a starting capacitor - bout 1/2 the size of this thing. I just wired it in parallel as there were lugs to do so on the original starting capacitor. And sure enough! The A/C compressor started, the Generator surged just a bit under the strain, then returned to normal speed - I base this on how it sounds - dont have a A/C volt meter. But worked very very well. I've run this combo for several hours to test the capacitor and the generator - no real issues other than if i run the A/C i can’t run really any other high amp device such as a microwave, but hey I didn't want to lug around a really heavy generator for camping and having some A/C while in the desert is fantastic. I should mention, that the Generator can start the A/C when it’s first turned on, but when the system pressurizes - that’s when the generator could not re-start the compressor easily. Now if there is at least 45 second between compressor cycles, this capacitor makes the next start of the compressor pretty painless without much struggle by the generator. I was told by someone that works on A/Cs that when the system is pressurized the compressor takes more power to start. For what its worth.

### ⭐⭐⭐⭐⭐ Helps our 2.5 ton, a ton
*by A***A on March 13, 2025*

I bought this a year ago to keep as a spare and recently since I was cleaning our 2.5 ton Goodman condenser I decided to just install it since everything was taken apart already. It's a simple install, just bolt the CAP to the unit next to the existing one, and then for our unit, connect it to the red and yellow terminals on the existing CAP. After reassembly, the first thing I noticed is that the condenser kicks on instantly now, before it would have a ramp-up of 15-20 seconds where it would slowly start up before getting to full speed. Now, that happens immediately. Highly recommend installing one of these.

## Frequently Bought Together

- SUPCO SPP6 Relay/Capacitor Hard Start Kit with 500% Increase Starting Torque
- VEXUNGA 45/5 uF 45+5 MFD 370V or 440V Dual Run Start Round A/C Capacitor 45 5 uF 370 440 Volt VAC CBB65B Air Conditioner Capacitors for AC Unit Fan Motor Start or Heat Pump or Condenser Straight Cool
- TITAN PRO, 1 Count (Pack of 1), No Color Packard TRCFD455 45+5MFD 440/370V Round Run Capacitor Replaces PRCFD455

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*Product available on Desertcart Uruguay*
*Store origin: UY*
*Last updated: 2026-02-20*