Check in & question re soft start for single AC

[Thelma jo]

Hi everybody! I'm new to this site and to the RV world. I was taking care of my mom who passed at the beginning of the year. I've sold my home and plan to "half-time" with my dog and cats. My daughter's house will be my home base when not traveling, so I can spend time with my granddaughters 😊

I recently bought a 2005 Born Free 24 RB and am getting it ready for extended trips.

My question is:. Does the RV soft start work for a single AC? I thought it did and that it would basically eliminate the initial burst of energy that an AC had when it first starts up. But the RV place I Took it to to be installed says that it is to regulate 2 ACs and would be a waste of money to put it on a single AC... Has anyone used this on a motorhome with only 1 AC? And if so does it eliminate that initial burst of energy? And can you use the AC when plugged into the regular house power?

Thanks for having me and answering my probably silly questions!

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined us!

I've never used it so can't help with that question.

Good luck, happy trails, and God bless!

[RichKimball]

Hi Thelma Jo.
It absolutely is designed for one a/c. If you wanted it for 2 units...you would buy 2 soft start devices.

It's sad that so many confuse what this great item does and how it functions. It will be a great addition to your camper helping you to power the a/c on small generators or even a 15a house circuit.

Please go straight to the manufacture for questions. RVGEEKS has some great reviews of the EasyStart and I believe still offer a coupon code as well. Micro Air Easy Start

[tpaul]

Agree that every type I've seen is for a single A/C. Maybe there are others? I don't know of anyone who regrets installing one as long as they under stand it's limits. It does make it easier to run an A/C on more limited current but what else you can run at the same time still depends on the size of your generator/power supply. For instance, I can run my 15K A/C on a Honda 2200 generator and works find. But if I want to run my microwave, hairdryer or other high current appliance I have to switch the A/C to fan while the other appliance is running. Could get a larger generator but don't really have the space. Plus I like how quiet it is. And I also converted it to propane so in a pinch, if my small spare propane tank runs dry I could run it off my RV tanks.

[wingnut60]

Did you get it installed? Obviously, the shop was confused in thinking it was to allow use of 2 ACs on 30amp.

[Thelma jo]

Thanks!

[KanzKran]

Originally Posted by Thelma jo

My question is:. Does the RV soft start work for a single AC? I thought it did and that it would basically eliminate the initial burst of energy that an AC had when it first starts up. But the RV place I Took it to to be installed says that it is to regulate 2 ACs and would be a waste of money to put it on a single AC... Has anyone used this on a motorhome with only 1 AC? And if so does it eliminate that initial burst of energy? And can you use the AC when plugged into the regular house power?

Thanks for having me and answering my probably silly questions!

No such thing as silly questions, especially when it comes to RV equipment and systems. Better to ask and get some answers than to muddle about, unhappy with your new purchase, or worse, do damage to your new purchase.

The soft-starter units mainly stagger the fan and compressor start events, and extend the start time of the compressor, thereby reducing the inrush current to the compressor windings. That’s typically in the 4-8 times running current range (typical of all induction motors), so a 12A compressor and fan running current can reach something like 70+A if started ‘normally’.* That’s not usually a problem with shore power, and in fact mine starts and runs just fine on my son’s 20A garage power when we visit them in TX. Circuit breakers can absorb large overloads for short time periods, by design, to allow motors to start and to handle the occasional short-term overload.

But trying to start an A/C unit on a little generator won’t usually work without a soft-start device, as they either suffer from severe voltage sag where motor starting torque drops like a stone with voltage reduction and therefore can’t start at all, or they just trip the circuit breaker on over-current. The soft-starter limits the starting current which prevents that.

Same thing on 30A shore power if there are two A/C units, with one already running, where the additional starting current may trip out the 30A breaker. That’s probably where the RV dude got the notion that it’s used for running two A/C’s on 30A shore power.

There’s no reason not to install a soft-starter on a single unit, and you can always remove it and go back to the OEM starting capacitor, but I would evaluate actual need before spending the money. Cost can be mitigated by doing it yourself of course, which isn’t hard.

*See running current and locked-rotor current for the compressor PLUS the fan when starting across the line (no soft-starter) in the Dometic sheet in the link. Since both the compressor and the fan are stationary when first started, locked-rotor current applies during start-ups. Also note the generator recommended minimum sizes, again as-designed.

https://epi.dometic.com/externalasse...4179_55897.pdf

[Thelma jo]

It's in the shop still, going to call on Monday to have them install. ��

[Thelma jo]

Thanks for all the help everyone!

[KanzKran]

Originally Posted by Thelma jo

It's in the shop still, going to call on Monday to have them install. ��

One final comment - make sure it’s actually a soft-start unit, NOT a hard-start kit. Hard-start kits are just a larger start capacitor with PTCR to cut it out of the circuit once started, and cost a fraction of what a true soft-starter does. They’re intended to increase the starting torque of the compressor under severe low voltage conditions (see my comment above about low-voltage and torque loss), which is not what you’re talking about here.

I’m only bringing it up because I’ve seen more than a few people confusing the two technologies.

[Persistent]

Make and model of the soft start are required for better advice.

[Marine359]

I self-installed an easy start on Dometic 13,500btu AC. Install was easy. Took about an hour. Now my AC runs easily on 15amp shore power, and on 2500w generator that only spits out 1,800w on propane. Highly recommend it.

[Thelma jo]

Thanks, it is a soft start for an RV, I double checked my confirmation email, just to be sure after I talked to RV place... It's SoftStartRV SSRV3TDC ��