Soft start capacitors

My Harbor Freight generator (2500W) (2200 run) would not start the Coleman 13,500 A/C on my Jaco TT. I bought a Supco hard start capacitor from Amazon, $6.95, wired it in according to the instructions to the run cap, turned on the A/C, nada, wouldn't start. So, I wired it into the start cap, turned on the A/C, voila, started right up without a whimper from the gen. Ran it for 30 minutes with no problems so I guess I'm good to go.

ktmrfs wrote:

2edgesword wrote:

Home Skillet wrote:
Over the years, I have tried all those hard start capacitors mentioned.

Nothing compares to the Micro-Air soft start.
No more generator surging when the a/c cycles, etc.

LINK

I would think if you're doing a lot of camping off the electric grid then the extra cost between a hard start capacitor ($10) and the Micro-Air Soft Start ($300) isn't an issue. For me the few times I anticipated and have had to run the A/C on a generator didn't justify the additional cost. It requires some human power management on my part (primarily no microwave while the A/C is running) but doable.

we do lot's of off grid camping and my experience with the soft start kits and a honda 2000 was it would reliably start the AC under these conditions.

1) sea level to 500ft, temps below 85F
2) generator warmed up turned off eco mode

and or course everything else turned off.

Once above 1000Ft especially with temps near 90F, it would not reliably start the AC even with the soft start kit. By 2000ft it was a 100% no go.

Now different brands and models of AC units vary, along with what generator you have.

As a comparison my second smaller trailer has a coleman "polar cub" a 9500BTU AC with a very good soft start circuit, optimized for low LRA and that AC unit I can start with the honda 2000 at 6000+ ft and any temps and run it all day long with no problems.

With the microair easy start with my Coleman MachIII I can leave the honda 2000 in eco mode and reliably and smoothly start the AC to at least 4500FT 95F, 6500Ft density altitude. generator ramps up smoothly.

Now at 6500FT density altitude the honda 2000 does run out of poop and will overload after about 20 minutes, so it did mean paralled honda 2000 at that altitude. But then I could get the batteries charged as well.

Son now has one of the honda 2000's, I have the honda 2200 so we shall see if the extra 200VA and 25% larger engine solves the altitude problem.

If a soft start kit solves the AC problem under the temp and altitude conditions you experience, go for it. If not, the micro air will solve the starting problem, but it doesn't lower running current so high altitudes may still be an issue with one generator.

If I were doing a lot of off grid camping the microair would be the way to go. I think the frequency of use versus cost factor is a major factor in making the decision which way to go.

I just installed 2 Micro Air Soft Starts. See my recent post (cooling improvements). Before, my 3400 watt Champion inverter generator would start one 15K AC at my home at 4600 feet elevation. At 7000 feet, forget it. I am anxious now to try it at elevation.

Our Class C came from factory with a 4KW Onan RV GenSet, and a Coleman Mach 15000 A/C with a model number that says it has OEM Hard Start. Inspection confirms that.

Chum lee wrote:
IME whenever a manufacturer designs/builds a situation/component that isn't as fool proof as possible, Murphy's law eventually takes effect.

In life, Murphy's Law states "Whatever can go wrong eventually will."

IMO, with regard to RV gennys and AC units, this is a manufacturers way of telling its customers, "Look guys and gals, just buy the correct size generator." (if you want your system to work reliably most of the time) The manufacturer has NO IDEA OR CONTROL OVER what foolish things their customers might try so they opt for the most fail safe mode possible. If you decide to alter their design, it now becomes your design and the manufacturer is quick to point that out to you when/if things go wrong.

Chum lee

x2 for that. The vast majority of aircon units on RVs never see any boondocking service let alone users wanting to run the unit with a small inverter generator on eco mode. Those are extreme edge-case scenarios.

IME whenever a manufacturer designs/builds a situation/component that isn't as fool proof as possible, Murphy's law eventually takes effect.

In life, Murphy's Law states "Whatever can go wrong eventually will."

IMO, with regard to RV gennys and AC units, this is a manufacturers way of telling its customers, "Look guys and gals, just buy the correct size generator." (if you want your system to work reliably most of the time) The manufacturer has NO IDEA OR CONTROL OVER what foolish things their customers might try so they opt for the most fail safe mode possible. If you decide to alter their design, it now becomes your design and the manufacturer is quick to point that out to you when/if things go wrong.

Chum lee

Adding a "hard" start capacitor that reduces the starting current would be a good thing for starting under low voltage conditions and where wire runs to a pedestal are long because the motor windings wouldn't get stressed as much at startup and could potentially reduce the chances of premature failure of an AC unit. How many RV-ers monitor voltage or know what good or bad voltage levels are tho?

I think all AC units should have them but just think of the increased purchase cost of a new RV... :R And just guessing, I would expect that the AC unit manufacturers would rather sell you a replacement AC unit than a capacitor.

2edgesword wrote:

Home Skillet wrote:
Over the years, I have tried all those hard start capacitors mentioned.

Nothing compares to the Micro-Air soft start.
No more generator surging when the a/c cycles, etc.

LINK

I would think if you're doing a lot of camping off the electric grid then the extra cost between a hard start capacitor ($10) and the Micro-Air Soft Start ($300) isn't an issue. For me the few times I anticipated and have had to run the A/C on a generator didn't justify the additional cost. It requires some human power management on my part (primarily no microwave while the A/C is running) but doable.

we do lot's of off grid camping and my experience with the soft start kits and a honda 2000 was it would reliably start the AC under these conditions.

1) sea level to 500ft, temps below 85F
2) generator warmed up turned off eco mode

and or course everything else turned off.

Once above 1000Ft especially with temps near 90F, it would not reliably start the AC even with the soft start kit. By 2000ft it was a 100% no go.

Now different brands and models of AC units vary, along with what generator you have.

As a comparison my second smaller trailer has a coleman "polar cub" a 9500BTU AC with a very good soft start circuit, optimized for low LRA and that AC unit I can start with the honda 2000 at 6000+ ft and any temps and run it all day long with no problems.

With the microair easy start with my Coleman MachIII I can leave the honda 2000 in eco mode and reliably and smoothly start the AC to at least 4500FT 95F, 6500Ft density altitude. generator ramps up smoothly.

Now at 6500FT density altitude the honda 2000 does run out of poop and will overload after about 20 minutes, so it did mean paralled honda 2000 at that altitude. But then I could get the batteries charged as well.

Son now has one of the honda 2000's, I have the honda 2200 so we shall see if the extra 200VA and 25% larger engine solves the altitude problem.

If a soft start kit solves the AC problem under the temp and altitude conditions you experience, go for it. If not, the micro air will solve the starting problem, but it doesn't lower running current so high altitudes may still be an issue with one generator.

Home Skillet wrote:
Over the years, I have tried all those hard start capacitors mentioned.

Nothing compares to the Micro-Air soft start.
No more generator surging when the a/c cycles, etc.

LINK

I would think if you're doing a lot of camping off the electric grid then the extra cost between a hard start capacitor ($10) and the Micro-Air Soft Start ($300) isn't an issue. For me the few times I anticipated and have had to run the A/C on a generator didn't justify the additional cost. It requires some human power management on my part (primarily no microwave while the A/C is running) but doable.

Over the years, I have tried all those hard start capacitors mentioned.

Nothing compares to the Micro-Air soft start.
No more generator surging when the a/c cycles, etc.

LINK