Micro-Air EasyStart Flex - HVAC soft start kit

[97K15004WD]

Is someone has one that has failed and is willing to post up pictures, I'd like to see one up close.

 

[TooManyWheels]

Is someone has one that has failed and is willing to post up pictures, I'd like to see one up close.

Some quit transmitting power and generate error codes, some fill with condensation, one was filled with what the owner described as "brown capacitor fluid", one burned to a crisp, others are reported to just quit. This is in the Facebook group Generators: portable generators to power entire house. The primary offender seems to be the MicroAir Flex.

 

[dnewton3]

UPDATE:

@97K15004WD this may be of interest to you

In a quest to understand the topic of harmonic distortion risk, I did email them yesterday. They responded this morning. I will say that is impressive customer relations, and the answer they gave was reasonably detailed. I believe, based on their answer, that any fear of a long-term degradation of my compressor motor from the Flex product is completely unfounded. I do not have the ability to "test" the product in this manner, but I accept their detailed answer as enough to assuage any concerns about the product.


Here is the reply:

Thank you for your detailed question regarding harmonics and the EasyStart Flex in relation to IEEE 519 standards.

The EasyStart Flex is engineered to provide a smooth, controlled start for single-phase HVAC compressor motors by gradually ramping up the voltage and current during startup. This approach significantly reduces inrush current, which is the primary cause of light flicker, generator overload, and mechanical stress on the compressor.

Addressing Harmonics:

• The EasyStart Flex uses advanced microprocessor-based algorithms to manage the startup sequence. Unlike some basic soft starters that may abruptly chop or modulate the AC waveform (potentially introducing significant harmonic distortion), EasyStart Flex is designed to minimize electrical noise and harmonics.
• The device’s intelligent learning process optimizes itself to the specific compressor, further reducing the risk of introducing harmonics that could affect other equipment or cause overheating.
• All EasyStart units undergo rigorous quality control and are UL approved, ensuring compliance with safety and performance standards.

Relation to IEEE 519:

• IEEE 519 is a recommended practice for harmonic control in electrical power systems, focusing on limiting harmonic distortion to protect equipment and maintain power quality.
• While the EasyStart Flex is not specifically marketed as an IEEE 519-compliant harmonic filter, its design inherently minimizes the introduction of harmonics during the start cycle. It does not operate continuously as a variable frequency drive (VFD) would, but rather only during the brief startup phase.
• The risk of compressor or fan motor overheating due to harmonics is extremely low with EasyStart Flex, as it does not introduce significant harmonic content into the system. Its operation is fundamentally different from some lower-quality soft starters that may use less sophisticated control methods.

Summary:

• EasyStart Flex is engineered to avoid the common pitfalls of poorly designed soft starters, such as excessive harmonic generation and associated overheating risks.
• It is a trusted solution in the industry, with over a decade of engineering refinement and positive customer feedback.

If you have a particularly sensitive application or require detailed harmonic analysis, I recommend consulting with a qualified electrical engineer.

I'll note again that this product only is active during a very short duration; less than 1 second during the ramp up. Given their explanation above, and the fact that the product actually REDUCES amp draw by a very significant amount during that period, I have to think there is essentially zero risk of this product causing a heat or harmonic failure mode of a compressor (or fan) motor.


If someone sees it differently, I'd certainly entertain opposing views. But we have to accept, without evidence to the contrary, that this Flex does not induce significant concerns of harmonic distortion and the associated risks of heating, etc.

 

[97K15004WD]

Sent DM

I would ask them what the failure effect mode is. IOW, if the unit fails, what is the impact on the compressor motor on the next start with the failed unit.

My biggest concern with this unit would be it fails, and you don't know it failed.

And the next time the compressor is called for, the compressor motor is stalled, overheats, and dies an early death because it can't start rotating under load without the starting circuit being functional and operating nominally.

Look at the "five whys" of this potential failure and it's impact on your system, and the cost associated with each.

 

[97K15004WD]

I found this one that was open. This one has three relays and a rated capacitor (3-step).

I doubt it's the same, but it's only one that I can find a picture of that is exposed. Which is kinda strange to me.

Regardless, if anyone opens one of the Micro-Aire units, I would love to see inside it.
.
.

 

[97K15004WD]

Here's a true single phase input, single phase output 3.0HP 230VAC VFD ($379.00)

https://www.amazon.com/Variable-Frequency-Drive-Single-Output/dp/B089Q3MHWG?th=1​

And there are bunches more from different brands such as ABB. Just easier to source thru Amazon for most non-commercial guys.

 

[dnewton3]

Regarding the MicroAir Flex unit ...
I asked about FMEA criteria; here is their answer:

1. Failure Modes & Compressor Protection:
   • If the EasyStart Flex experiences a failure, it is engineered to default to a safe state. The most common failure mode is for the unit to become electrically open, meaning it will not attempt to start the compressor. This prevents the risk of inadequate start capacitance or improper phasing, which could otherwise damage the compressor.
   • The EasyStart Flex does not have a mechanical or automatic “bypass” mode. If the device fails, it does not revert to a traditional hard start circuit or allow the compressor to start without the soft starter’s intervention. This is a deliberate safety feature to avoid the risk of improper starting conditions.
2. No Start Capacitance on Failure:
   • In the event of a failure, the compressor will not receive start capacitance from the EasyStart Flex. The system will simply not start, which is a safer outcome than attempting to start with inadequate or incorrect capacitance.
3. Diagnostics & Alerts:
   • The EasyStart Flex continuously monitors for fault conditions (such as overcurrent, brownout, miswiring, or short cycling) and will lock out operation if a critical fault is detected. This helps prevent compressor damage and provides clear diagnostic feedback via the onboard LED and the EasyStart Diagnostics app.
4. Industry Best Practices:
   • This approach aligns with industry best practices for soft starters, prioritizing compressor protection over continued operation in a compromised state.

 

[meep]

I’d like to know how this works out long term. These are very common on RV ACs because of just about every challenge in managing power at different campsites or generators. I’ve heard of no failure patterns in the typical rooftop camper AC, some of which do get used several months out of the year for a long time, often on dubious power. Granted, those are much smaller loads - 15A compressor at 120V … idk, 1 ton units?

I’d love to eventually install a genset on my home and preferably a smaller one (natgas isnt free) running only selected branches. I know I’ll have to argue with the guy who just wants to look at the panel, follow a policy and “22k is what you need.” I’ve watched 2.5 tons run all week long on a 6.5k genset. A soft start would add a lot of headroom.

@dnewton3

 

[spasm3]

So is this basically an add on capacitor that stores more startup current ?

 

[Lubener]

I would also believe the soft start also eases the sticker shock some on one's electric bill.

 

[AZjeff]

So is this basically an add on capacitor that stores more startup current ?

It has a cap but it also electronically lengthens or smooths out the big start up hit. I installed a MicroAir SS on the travel trailer when we got it in late 2020 so I could start and run the AC with a small generator. Without it I couldn't start the AC with a 3500 watt Honda. With it I can start and run the AC with a 2500 watt Westinghouse. It would start with a bang without, with you barely hear the compressor come on because the blower comes on first. We're into the 6th year of use and I never even think about it. I'm an idiot when it comes to electronic things and electricity but when the function is like the difference between dumping the clutch every time or letting it out smoothly and needing less current to get the AC going that should be a good thing? I've been thinking of one for the home unit that's 8 years old.

Lots of negativity about something not fully understood. They don't seem to be a garage business selling a marginal product made in China. https://micro-air.com/

 

[meep]

So is this basically an add on capacitor that stores more startup current ?

It’s been a minute since I looked up the theory but if I remember it basically chops up the AC power coming in, with a pulse-width-modulated ramp-up. Meaning it’s operating on the same base frequency and voltage but it’s only at first getting glimpses of it, like looking through a comb, and then over 3-4 seconds the comb becomes less and the space between the tines become more. The units need a cap or two in them to manage all the extra artifacts which come from that cycle, but not to store additional power.

I think.

It’s been a while.