How does an A/C Soft Start WORK?

A soft start connects to the air conditioner’s compressor and modifies how it operates when it turns on.

Instead of drawing as much power as possible instantly, a soft start will gradually increase the power draw until the air conditioner’s compressor fully kicks on.

Electrical soft starters reduce voltage or current input temporarily by reducing torque.

Some RV A/C soft starters may use solid-state devices to help control the flow of the current. They can control one to three phases. And a 3-phase control usually produces better results anyway.

Most soft starters use a series of Thyristors or Silicon Controlled Rectifiers (SCRs) to reduce the voltage. In the normal off state, the SCRs restrict current but in the normal on state, they allow current.

The SCRs are engaged during ramp-up and bypass contactors are pulled in after maximum speed is achieved. This helps to reduce motor heating.

RV AC soft starters can be used in applications where:

• • • Speed and torque control are required only during startup (and stop if equipped with soft stop).
    • Reduces large start-up inrush currents associated with large motors is required.
    • The mechanical system requires a gentle start to relieve torque spikes and tension associated with normal startup (e.g. conveyors, belt-driven systems and gears).
    • Pumps are used to eliminate pressure surges caused in piping systems when fluid changes direction rapidly.

Does my RV really need an AC soft start?

In our opinion, yes, your air conditioner should have a soft start installed and here’s why.

An AC soft start ensures your compressor ramps up more gradually when starting, which brings two key benefits.

It reduces wear and tear on your compressor, potentially extending the life of your RV’s air conditioner.

And, the initial start-up is much quieter which your campground neighbors and even you will appreciate.

Soft starters are often the more economical choice for applications which require speed and torque control only during motor start-up.

They are the ideal solution for applications where space is a concern.

And, RV A/C soft starters usually take up less space than variable frequency drives.

What can I run on my RV AC soft start?

After installing your A/C soft start correctly, you can run your RV air conditioner with minimal start-up power.

This applies even on 2 units on a 30 amp pedestal. Soft starters are designed to connect directly to the compressor motor and reduce the power surge that occurs on startup.

They employ a four part, self-optimizing start ramp sequence using the lowest possible start-up current.

Soft starts gradually increases this power until the compressor is running, creating a very smooth start that reduces the peak current by 50 to 70% or more.

An RV rooftop 16000 BTU, 120-volt compressor can now start with under 20 amps of current.

With your soft starter you can operate:

• • • 1 air conditioning unit using a small portable generator
    • 2 air conditioning unit on a 30 amp electric hookup
    • 1 air conditioning unit on a 20 amp household electric hookup
    • 1 or 2 air conditioning units using your RV’s onboard inverter system

These air conditioner soft starters are specially designed, engineered and tested for all RVs; from the smallest campers to big rig fifth wheels and motorhomes.

Other AC soft start benefits;

• • AC soft starts reduce and eliminate the  compressor’s start-up clunking noise.
  • They also reduce startup power demand by approximately 70%. 
  • Soft starters are a little smaller than a brick (6”x3”x3”) and weigh less than 2 pounds.

There are two major RV AC soft start products on the market; Micro-Air EasyStart™ and Network RV SoftStart RV™.

We can say that we’ve tested both of these soft starter brands (we received no compensation).

To be honest, there are really no major differences in the two when it comes to performance.

Can you install an A/C Soft Start yourself?

If you get a little queasy getting on the roof, then you’ll want to leave this type of installation to a professional installer or another RVer who knows what the heck he/she is doing.

But, it’s going to cost you about an hour or two labor or a case of brews and a couple steaks on the barby.

However, if you’re an RV DIY installer, soft start installation is actually pretty simple and should take no more than an hour to install each unit.

Your soft starter will come with a set of instructions from the manufacturer or direct you to their website.

And, as easy as it was for Dan to install one on our Landmark fifth wheel (Dometic A/C units) and our Winnebago View (Coleman A/C unit), he said,

“it’s not rocket science. You just have to pay attention to the different wiring per air conditioner manufacturer”.

See how Dan helps Sean from Chickery’s Travels install their Micro-Air EasyStart™ on their former Heartland Cyclone fifth wheel toy hauler.

EasyStart™

The EasyStart™ is a viable solution for RVers who are looking to run an air conditioner or refrigeration compressor on a generator, inverter, or limited utility power.

It can also be applied to air compressor and fluid pump motors. The EasyStart™ delivers up to 65-75% start current reduction.

• • • Start your A/C without buying a second or bigger generator or inverter
    • Run 2 air conditioners on a 30-Amp cord (Note: Each A/C requires an EasyStart™ unit)
    • Sleep with less noise and at a comfortable temperature all night
    • Run your A/C and other appliances at the same time
    • The standard version can support both 115-230VAC/50-60Hz motors, and the RV version supports only 115V/50-60Hz motors.
    • Has numerous specialized fault checks not found in any other soft starter to provide further protection for your compressor.
    • The EasyStart™ 364 is capable of supporting up to a 36000 BTU (3 ton) compressor. It includes a fully-weatherproof (IP65), flameproof, plastic enclosure with an integrated mounting flange and a 40″ (1m) wire harness.
    • Specialized models exist for various applications.
    • Convenient Installation Kit for wiring an RV Rooftop A/C unit is available. (sold separately)