Imagine this: you go out to your local entertainment big-box store and purchase the top of the line “HUMONGOUS” television.  When you get home, you don’t think anything about it and just go ahead plugging it directly into the wall socket, right?  What’s that you say, ludicrous?  Of course, we would only plug that piece of beautiful technology into a UL rated surge protector!

     So, I gave it away in the first paragraph: a UL rated surge protector.  But, don’t you want to know why?  Or what happens if you don’t?  Anyone that knows me has heard me say that I usually ‘learn the hard way – at least once!’  So, when a top-end ductless installation went wrong after months of perfect operation, I had to ask the question, why this one?

     You see, poor Mr. Jones’ house lost power during an electrical storm.  The fact his cable box and other minor electronics failed should have been a giveaway as to what happened.  Everyone knows when these electronic boards are put together in the factory they come with little canisters attached.  In these canisters is a specific amount of smoke, and power fluctuations have a way of letting this smoke out.  No smokey = No worky.

     Unfortunately (depending on the view here), this high end ductless system was resilient.  The unit would turn on, operate for about a minute or two, and then shut down with no error codes or reason.  Frustrating, right? So, we call the tech support line from the house and they determine I must replace the main control board – parts and labor (my generosity as part of the install) warrantied.

     Two days later, yes it snows in New England and it would have been longer if this was in 2015, I return with the part.  Install the latest and greatest control board, smearing white heat sink paste all over anything within eyesight, and…no luck!  Another call determines a combination of control boards should be replaced together.  Thanks for that one OEM Rep!  Another few days later, replace the boards, and once again the same symptoms.  This time, I have to offer the customer a new condenser.

     So I start to think, what could I have done differently to avoid an act of god?  Boy, if I had a solution to all of those questions.  But then it hit me, a surge protector!  In order to pass the electrical inspection, and my anal electrician, said surge protector must be UL listed (this adds to the price).  There are many models that attach to either the outdoor disconnect (weather tight casing) or into the main panel.  I prefer the models that have an indicator light, telling the homeowner if they are still protected.  Either way, this would take the surge and not your new high-efficient HVAC equipment.  This is not a code requirement, so often gets overlooked.  Besides, your equipment that just cost you at least three times your big screen television is not sexy and tucked away in some basement or behind the overgrown shrubs.  Spend the extra few dollars and protect the investment in your comfort!  I think I may start tying my labor warranties to the installation of a surge protector, or just make it part of the installation price.  Just like condensate traps on furnaces, or liquid line filter driers in condensers, if this becomes commonplace why would an OEM not just install these at the factory?  Imagine how many ECM or condenser control boards they warranty over the years?!

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  • Electronic solid state phase protector has been around for some time now with the advancement in the semiconductor technology. It has enabled the design of this device that is used as part of the motor controls. They are accessory devices that designers used to protect the motors from premature failure due to voltage faults.

    In the field of HVAC, these devices are used to protect large three phase fan motors and compressor motors from being damaged.

    Ductless Mini Split Air Conditioner Heat Pump Central System
  • Excellent work I was not known to many of the thing but now Its clear enough to me. Thanks

  • Chris, you will be happy/unhappy to know the same initial cost/quality cutting mentality existing in industrial control equipment too. There is a PLC controller inside almost every machine, every industry including transportation and infrastructure.  

    (If you want the most simple explanation of what is a PLC, click the above link PLC controller to a youtube video we made explaining it for the layperson.)

    In an industrial environment with big electric motors and all, the electrical supply can often more dirty than a consumer's home. A very common problem maintenance and service techs address with the PLC is the program gets "Zapped". This cost the end user (manufacturer/company) many thousands in downtime, reloading the program in PLC and sometimes unwittingly and even needlessly replacing parts like the expensive processor itself. Very similar to the situation you describe Chris for HVAC system. The root cause almost no one addresses... in the industrial control panel with PLC (computer control) they do not put a UL surge protector. They come straight off the secondaries of a 480v power transformer, with the 120v to power the PLC (computer). This echoes the surge during power outages right to the sensitive electronic controls (PLC). To give those not in the industry and idea of the cost scale of this oversight, for just one company... the PLCs themselves cost thousands, the machines often a quarter of a million dollars, the downtime accumulated of 5-10 years, millions.

    I recently wrote an article about in Control Design Magazine at  

  • Excellent article.
    We have in our engineering practice a section on protection of electronic devices. While public bid laws rather constrain us, we are partial to Price-Wheeler "Brick Wall" surge suppressors. Very robust and simple units that meet MilSpec and other governmental specifications but have, that I can find, no peer.  Full disclosure, I have zero interest in the product or company, just like them.

    We have not applied them to entire buildings but have used them at DDC panels and where electronics are found such as on VRV systems. They also make UPS units and power conditioners.

    One caution on UPS units though and it may seem obvious but stuff happens. One must apply UPS devices only on the line side of boilers and other safety shut-down appliances, lest one defeat a safety device such as a low water cut-off, etc. that may be part of the line voltage circuit. Sorry if glancing off-topic, but I thought worth mentioning.

  • And this is EXACTLY why we offer complimentary labor to replace factory warranted parts on SEER 16+systems we install and semi-annually maintain...

    BUT only if the client also chooses to have installed whole house surge protection whose status lights we check as part of PM.

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