What Is an Air Conditioner Hard Start Kit?

2017 Jul 07
Posted in: Air Conditioning

A hard start kit is an energy-storing capacitor that helps your A/C start when it’s struggling to turn on.

Like their name suggests, hard start kits help solve a problem called hard starting, which is when an A/C struggles to turn on and then shuts off abruptly after a short while.

If you hear a stutter or clicking noise when you turn on your A/C, and your A/C doesn’t stay on for long, then those are signs your air conditioner is hard starting.

Contact a Phoenix A/C professional if your air conditioner/heat pump is hard starting. It could cause serious damage to your cooling system, so you should get it fixed ASAP.

In this article, we’ll answer these 2 questions:

  1. What exactly does a hard start kit do?
  2. Do I need a hard start kit or something else?

Let’s start with question #1...

What does a hard start kit do?

Here’s the bottom line: A hard start kit makes your A/C start smoothly and quickly, which reduces damage to A/C parts and prolongs the life of your cooling system.

But why does an A/C have a hard time starting up in the first place? 

Well, when you turn on your A/C, its compressor (the “heart”) powers on to help the system cool your home. However, starting up the compressor requires 4–8 times more electric current than running it.

That’s a lot of electrical juice!

Over time, this jolt of power, which creates a surge of heat, can damage the compressor and other important A/C components—especially if your compressor is already old and worn out. And if your compressor is already worn out, it requires even more electricity to get it to shift from “start” to “run” mode.

That’s when a hard start kit saves the day: A hard start kit shortens the startup period of the compressor and reduces the amount of electricity it takes to start your A/C.

In fact, with a hard start kit, the electrical efficiency of the startup process is as high as 98%, compared to an efficiency of only 50% without one. This efficiency reduces heat and wear on the compressor and other important A/C components.

OK, so you know a hard start kit helps your A/C compressor turn on. But do YOU need a hard start kit?

Do I need a hard start kit?

You should consider installing a hard start kit if you find yourself in one of these scenarios:

Scenario #1: Your A/C is already hard starting

If your air conditioner is already hard starting, you should contact a professional ASAP to investigate the problem. 

“How do I know if my A/C is hard starting?”

You’ll know if you notice these 4 signs:

  1. A/C starts, then quickly shuts off after you turn it on: This is called short-cycling, and it means there’s something wrong with your compressor.
  2. You hear clicking noises when the compressor starts: A clicking sound points to a problem with your compressor, which is using too much power to turn on (hard starting).
  3. Your compressor trips your circuit breaker: This means your air conditioner is using too much energy to start, so your circuit breaker trips before any serious electrical damage occurs. This is a symptom of hard starting.
  4. Your lights flicker when you turn your A/C on: This is normal to a certain extent, but if you notice a dramatic flicker then it means your A/C is drawing too much power to start, which is a symptom of hard starting.

Solution: Contact a professional to investigate the problem. If your compressor motor is struggling to turn on, then a hard start kit could potentially solve the issue.

However, if your compressor is near the end of its life, then a hard start kit may prolong its life for a short time, but shouldn’t be viewed as a long term fix. If your compressor is about to die, talk with your technician about replacing your A/C system (it’s usually more cost-effective to replace your whole system rather than buy an expensive compressor).

Scenario #2: You have a new air conditioner

In the past, most single-phase A/Cs came from the manufacturer with built-in hard start devices, but many newer A/C models don’t include a hard-start kit.

If your air conditioner doesn’t have a built in hard start kit (your technician will let you know), you should consider having a professional install one. If your compressor is new and in good shape, a hard start kit could extend its life and help it start even in difficult conditions like low voltage or high head pressure.

Need a hard start kit for your A/C or heat pump?

Contact George Brazil to schedule an A/C repair. We’ll send one of our trusted technicians to visit your home and install a hard start kit for your air conditioner.

We’ve been serving Phoenix families since 1955.

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