RV.Net Open Roads Forum: Tech Issues: AC Hard start additions

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > AC Hard start additions

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next
Sponsored By:
wing_zealot

East of the Mississippi

Senior Member

Joined: 12/31/2007

View Profile


Online
Posted: 08/06/21 07:23am Link  |  Quote  |  Print  |  Notify Moderator

I'd rather put the $300+ it cost for a micro-air easystart into the ability to generate more amps. Much more useful around the house to have the ability to generate more amps than to have a one trick pony. For me, a micro-air may be the cheaper solution but its not the best use of my money. I'd invest my money towards the ability for a wider array of uses; even if at first blush it cost more; YOMV.

ktmrfs

Portland, Oregon

Senior Member

Joined: 06/22/2005

View Profile


Offline
Posted: 08/06/21 09:02am Link  |  Quote  |  Print  |  Notify Moderator

wing_zealot wrote:

I'd rather put the $300+ it cost for a micro-air easystart into the ability to generate more amps. Much more useful around the house to have the ability to generate more amps than to have a one trick pony. For me, a micro-air may be the cheaper solution but its not the best use of my money. I'd invest my money towards the ability for a wider array of uses; even if at first blush it cost more; YOMV.


for us, since we already had honda 2200 and a honda 2000, the micro air was our choice. Now we seldom need to parallel the genny's saving time during setup, and in about 90% of the times we need are off grid, only need to bring along on 50lb genny. Worth the $ for us.

If it was a case of no genny and deciding what to do it would for us be a decision of how much more weight am I willing to lift to get a bigger genny out of the truck and how much it costs vs. micro air cost and lighter genny.

Ends up being a personal decision on what works best for each individual.


2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2015.5 Denali 4x4 CC/SB Duramax/Allison
2004.5 Silverado 4x4 CC/SB Duramax/Allison passed on to our Son!


mr_andyj

Georgia

Senior Member

Joined: 11/13/2004

View Profile



Posted: 08/06/21 09:22am Link  |  Quote  |  Print  |  Notify Moderator

Just getting a bigger gen is not always an option for everyone. The small gens have advantages and for some it is a small gen or no gen. Given that, the question is how to run the AC off the small gen, not "just get a bigger gen"

The only thing new is the electronic soft-start that has come on the market instead of just adding a capacitor. Capacitors help, but only give you a boost of power that may or may not be enough to do the job, where the soft-start will make the motor start slower and require less of a power surge. The electronic ones are expensive compared to a $20 capacitor.

forums are full of
"just take it to the dealer"
"have a mechanic fix it"
"if you have to ask then you are not qualified to work on it"
"spend some of your money you cheapskate"
answers
None are helpful to the OP

Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 08/06/21 09:57am Link  |  Quote  |  Print  |  Notify Moderator

mr_andyj wrote:



forums are full of
"just take it to the dealer"
"have a mechanic fix it"
"if you have to ask then you are not qualified to work on it"
"spend some of your money you cheapskate"
answers
None are helpful to the OP


Forums are also full of folks attempting the impossible.

As one poster mentioned, typical RV AC can have as much as 50 Locked Rotor Amp draw for a second or two. There is only so much that a piddly 2Kw gen can do. That 50A locked rotor amperage is more than TWICE the surge rating on a Honda 2200i ( specs HERE )

" AC Output 120V 2200W max. (18.3A), 1800W rated (15A) "

Heck even just the continuous running current of a 13.5K RV A/C is roughly 13A and in extreme hot weather can rise to nearly 15A.

Soft starts are not magical creatures that make amperage come out of thin air and folks are being encouraged to not only run on a horribly undersized gen for the job but to sink more money into devices which help you abuse your A/C and your gen..

A $300 add on to a $800 A/C in order to fully abuse your $1200 gen? [emoticon]

So, you now have $2300 worth of potential collateral damage all so you don't have to carry an additional 50 lbs worth of gen.. [emoticon]

There are easy ways to get around the moving/lifting additional weight of a larger gen and you don't have to sacrifice your A/C or your gen in the process.

TurnThePage

North ID

Senior Member

Joined: 10/08/2003

View Profile


Offline
Posted: 08/06/21 10:43am Link  |  Quote  |  Print  |  Notify Moderator

So... Are you saying that soft start devices harm or stress the A/C? Hard start caps also reduce that "thump" that happens at the moment the compressor fires up.

I totally agree that a properly sized generator should be used, but I've never heard from any reputable source that there is any harm in using hard start caps or soft start electronics.


2015 Ram 1500
2004 Pioneer 18T6

2oldman

NM

Senior Member

Joined: 04/15/2001

View Profile


Offline
Posted: 08/06/21 12:02pm Link  |  Quote  |  Print  |  Notify Moderator

mr_andyj wrote:

Just getting a bigger gen is not always an option for everyone.
Answers aren't supposed to be applicable to everyone always. We don't even know what kind of generator the OP is talking about, but trying to run air from an undersized generator is not the best idea.

Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 08/06/21 12:43pm Link  |  Quote  |  Print  |  Notify Moderator

TurnThePage wrote:

So... Are you saying that soft start devices harm or stress the A/C? Hard start caps also reduce that "thump" that happens at the moment the compressor fires up.

I totally agree that a properly sized generator should be used, but I've never heard from any reputable source that there is any harm in using hard start caps or soft start electronics.


If the gen voltage sags well enough before tripping a breaker or sending gen into overload, absolutely.

Softstart devices which "ramp up" voltage over time in an attempt to break loose the locked rotor are doing the very same thing that everyone on this forum crys foul over with sagging campground voltages by electronically reducing voltage going to the compressor then ramping it up (IE "soft start") over a short period of time.

There is no "free lunch"..

Additionally, the "add ons" may work OK in your driveway in 80F temps but add in elevation at your campsite and more heat and you have a good chance that it isn't going to work reliably or at all.

Why bother messing around with a undersized gen and hoping it will work fine.

For those scared of 50lbs more weight, get creative. You can buy a nice set of light weight aluminum fold up ramps and wheel it right on. You can get portable lift tables with wheels which are nice, a little creativity you can find quite a few ways to safely hoist or lift a 100 lb gen..

Heck for myself, I use my tractor front loader to lift and place my 100 lb 4Kw gen into my truck bed.. I also have used 10ft boards with cheap aluminum ramp ends to ease the gen on to the tailgate..

I do cheat a bit and leave the gen in the truck bed and run it when needed..

philh

Belleville MI

Senior Member

Joined: 05/11/2015

View Profile


Offline
Posted: 08/06/21 03:21pm Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:


Heck even just the continuous running current of a 13.5K RV A/C is roughly 13A and in extreme hot weather can rise to nearly 15A.

I measured amp draw of my 15k AC, and running watts was a whopping 1200, aka 10 amps. My 2500 watt generator had no problems once I installed Microaire Easy Start

ktmrfs

Portland, Oregon

Senior Member

Joined: 06/22/2005

View Profile


Offline
Posted: 08/06/21 04:46pm Link  |  Quote  |  Print  |  Notify Moderator

Gdetrailer wrote:

TurnThePage wrote:

So... Are you saying that soft start devices harm or stress the A/C? Hard start caps also reduce that "thump" that happens at the moment the compressor fires up.

I totally agree that a properly sized generator should be used, but I've never heard from any reputable source that there is any harm in using hard start caps or soft start electronics.


If the gen voltage sags well enough before tripping a breaker or sending gen into overload, absolutely.

Softstart devices which "ramp up" voltage over time in an attempt to break loose the locked rotor are doing the very same thing that everyone on this forum crys foul over with sagging campground voltages by electronically reducing voltage going to the compressor then ramping it up (IE "soft start") over a short period of time.

There is no "free lunch"..

Additionally, the "add ons" may work OK in your driveway in 80F temps but add in elevation at your campsite and more heat and you have a good chance that it isn't going to work reliably or at all.

Why bother messing around with a undersized gen and hoping it will work fine.

For those scared of 50lbs more weight, get creative. You can buy a nice set of light weight aluminum fold up ramps and wheel it right on. You can get portable lift tables with wheels which are nice, a little creativity you can find quite a few ways to safely hoist or lift a 100 lb gen..

Heck for myself, I use my tractor front loader to lift and place my 100 lb 4Kw gen into my truck bed.. I also have used 10ft boards with cheap aluminum ramp ends to ease the gen on to the tailgate..

I do cheat a bit and leave the gen in the truck bed and run it when needed..


my experience with a Coleman Mach III 13.5K BTU AC non "high efficency", honda 2200, micro air easy start, at 7,000 ft altitude, outside temps near 100F. Density altitude near 8500ft.

AC starts smoothly and quickly with generator in eco mode, doesn't ramp up to full rpm. Had the converter off. Next, how much "spare" power could the honda 2200 supply at 7,000ft when outside temp was near 100F and AC running? changed the fridge to AC from propane adds about 300W. Genny still running not in overload. Voltage from the generator still at 122V. turned on the converter with the batteries near full charge, generator still running hours later still at 122 v

measuring generator output voltage during startup with a NIST traceable meter that will catch 10ms windows shows the lowest voltage during startup is 115V RMS, actually higher than some campground voltages!

Measuring running current with a calibrated clamp on meter shows I'm still below the continous current rating on the 2200 on AC only. So, given that I doubt I'm overstressing the generator.

Now a honda 2000 will overload at about 3,000Ft. The 2200 in addition to have 200more VA, has a 25% larger motor so in a sense honda has overcome the altitude derating of most generators.



BTW the micro air easy start has a "overload" sensor that is quicker and more stringent on overload than the honda. It will kick out the AC if it senses an overload instead of waiting for the generator to kick out, then after 10 minutes try a restart. As a test I turned on another 500W load to see what the micro air would do sense that would overload the generator. AC quit, honda dropped down in rpm to supply the other loads. turned off the 500W load, 10 minutes later AC came back on.

next tried the same thing but this time turning on the microwave. Same results, AC quite, generator kept the microwave running.

Conclusion: 1) My honda 2200 will run a coleman MachIII with easy start at 7000ft altitude continously without exceeding continous rating. 2) Micro air does an excellent job of detecting possible overloads and acting as a load shed device shedding the AC under overload.

How other 2000ish generators do, don't know. Some probably would work just fine, others likely are like the old honda 2000 at higher altitude.

2oldman

NM

Senior Member

Joined: 04/15/2001

View Profile


Offline
Posted: 08/06/21 05:00pm Link  |  Quote  |  Print  |  Notify Moderator

ktmrfs wrote:

How other 2000ish generators do, don't know. Some probably would work just fine, others likely are like the old honda 2000 at higher altitude.
My old Honda 2k really struggled running my Briskair 13.5. Two, no problem.

My 2200 runs it ok, but I just don't like working it that hard.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > AC Hard start additions
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.