310.4 Electrical Connections and AC Disconnects

Installing According to Code is the Sign of a Real Professional

So many times when you’re out in the field you’ll encounter a technician, a supervisor or inspector who will cite building codes as their authority for proper installation of an HVAC system.  Installing a subpanel, wiring up a disconnect, or running PVC pipe in the attic correctly is just one of the many responsibilities of an HVAC technician.

Whether you pull permits or not on your job, a company’s worth is based on the quality of its workmanship.  And if that work fails in a few years, it most likely wasn’t installed according to code.

So often you will notice the code referring us back to the manufacturer and how they want it installed.  Referring to the installation guide and following along with the steps in the book will take any and all guesswork out of what you’re supposed to do next.  This is the sign of a real professional in their trade.
I’m not here to claim I know, or could even possibly interpret all the codes correctly, but what I would like to do is open up some conversation about the building codes and your opinion about what we are talking about this particular day.

Electrical Connections at the Condenser

Today I want to talk about installing a service disconnect at the condenser.  I will look at one of the first points made in the California Mechanical Code and it stands out from the International Mechanical Code which just advises following the NEC when it comes to this.  But as an installer, I’ve wondered whether or not to put a disconnect here.  Let’s take a look at what 310.4 says about Electrical Connections.

First, “equipment regulated by this code requiring electrical connections of more than 50 volts shall have a positive means of disconnect adjacent to and in sight from the equipment served.”  This just means a furnace would need a 120-volt pigtail as its positive means of disconnecting voltage from the furnace.  When you unplug the furnace, no voltage can reach the furnace.  A 30-amp or 60-amp service disconnect is installed on the 240-volt circuit to the AC outside as its positive means of disconnect.

Here’s a question for you.  Let’s say we’re installing the AC unit.  Usually, the disconnect is right next to the condenser so the service tech can access the unit safely.  Must we always have a disconnect next to the AC to remove power from the unit?  The answer is no.  If the main electrical panel is within sight of the condenser, that can serve as the means of positive disconnect for the unit.  The double pole breaker inside the main electrical panel is that means of disconnect.  This has come up a few times for us when teaching new technicians.

Dedicated Outlets

Next, “a 120 Volt receptacle should be located within 25 feet of the equipment for service and maintenance purposes.  The receptacle need not be located on the same level as the equipment.” 

So, because we service our equipment with pumps and motors that require electricity, an outlet needs to be within reach of a 25 ft. extension cord.
As specified later in the codebook, in the case of a package unit installed on a roof, a dedicated outlet at the unit must be installed in certain jurisdictions.  Here in Yolo County, right next to Sacramento County, we must install 120 weatherproof outlets at the package unit on the roof we’re servicing in order to meet that city’s more stringent adaption of the code.  This allows us to use our vacuum pumps and recovery machines up on the roof.

Exposed Thermostat Wiring

The third part of this code requires that “low voltage wiring of 50 volts or less… shall be installed in a manner to prevent physical damage.”   This is kind of a pet peeve of mine.  It bothers me to see thermostat wire running to the AC with its brown sheathing exposed to the sun’s UV rays.  Even the slightest bump of a dried out thermostat wire against the AC is enough to strip the wire and expose it to an electrical short.  One-half-inch conduit should be run with the thermostat wire to protect it from damage.  It really doesn’t take any extra time to install this flexible non-metal conduit right into the condenser.  Some techs just don’t think about it, because they weren’t taught that way.  It’s all good.  Once again, just starting a conversation about this.

Your Turn

What are your thoughts about this section of the code that talks about electrical connections?  Do you always put a disconnect next to the AC even though it’s in sight of the main electrical panel?  Please leave your thoughts below.

Thanks for weighing in, and stay tuned for next week’s blog topic!

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What Happens on a Fox Family Air Conditioning Tune-Up?

What Is It?

An air conditioning tune-up is what responsible homeowners do to maintain their home’s HVAC system.   It’s a thorough cleaning and testing of the air conditioning system, to ensure that it’ll work when you need it to this summer.  We operate with the understanding that a clean system will run longer than a dirty system.

Not every HVAC company in town performs air conditioning tune-ups.  I would say it’s because they feel they’re not very good money generators for them.  I get it, wiping down air conditioners and testing parts aren’t very exciting for some.  But I don’t think they understand the opportunity they have to create a relationship with someone and their HVAC system.

I like to develop relationships with my customers by taking care of their AC system every spring.  If we can perform an AC tune-up every spring, for years and years, I know my customers will, at the very least, allow us to provide a quote for a new system when the time comes.  At the same time, our customers get to work with Sacramento’s most honest air conditioning company.  Our technicians will only bring up parts or repairs that will make the system return to factory standards, help it last longer, and make it safer for their families.

What Will Happen at My Tune-Up?

When we are on the way, our technician will call you and let you know.  We are proud to park on the street in our bright white vans with the Fox Family logo on it.  After you open the door and allow us to come in, we usually start at the air filter and thermostat.  I like to ask if there are any areas of the house that need any attention.  Do any rooms not get the right amount of air?  Does it cool the house down to your satisfaction in the middle of summer?  Questions like this can establish how you like your system to run.  Because not every homeowner is the same, right?

Once I know what’s going on in your mind as a homeowner, we will turn the AC system on, together, at the thermostat, listen for the air to come on, and walk outside to make sure everything out there is at least running.  Now we all know the system was running when we arrived!  From here, you’ll be able to sit back and do whatever you need to do while the tech goes out and runs through a list specifically designed for your type of air conditioning system.

We usually start out at the air handler in the attic or closet.  As a responsible business owner, if the furnace is in the attic, I need my techs to get in and out quickly.  It’s hard to ask a tech to spend time cleaning a furnace in a hot attic.  The furnace gets physically cleaned during the furnace tune-up, rather than during an AC tune-up, but there are some really important things to check here, so we try to get in and get out effectively and safely.

The most important thing we’re testing is the temperature difference between your supply and return air ducts.  If it’s not where it needs to be, we have a series of checks we will do to get it right.  A quick look at the evaporator coil can make a huge difference in the comfort of your home this summer.  If it’s dirty or clogged it will make your system underperform.

We also need to make sure your blower and the flywheel is clean and ready to run a lot in the coming summer months.  The tech will pour water down the drain lines to make sure the condensate drains properly.  We always offer the option of a condensate safety switch to protect your home from potential damage.  The secondary drain pan under the evaporator coil in the attic is a potential source of problems as well, so we make sure it’s ready for any emergencies.

Additionally, we’ll make sure the metering device for your refrigeration system is mounted properly while checking for any obvious refrigerant leaks in the copper tubing.  We’ll also check for proper insulation levels in your attic because it creates such an effective barrier between the hot air in the attic and the cool air you’re trying to keep in your house.  It pays to have a thick layer of insulation up there!

Once we’re done in the attic — and I really only want my techs up there maybe fifteen minutes on warmer days — we’ll head to the outdoor unit where the majority of the AC tune-up is done.  Here, we test the components inside the panel, focusing on things like your refrigerant levels to ensure your system isn’t running too long, unnecessarily.  The high and low voltage electrical running the AC needs to maintain a certain sizing, workmanship, and integrity to it.  All in all, we check about 35 items on the outdoor unit and 20 items on the indoor unit.  If you happen to have a packaged unit that sits on the side of the house or even up on the rooftop, we still check all 55 items.

After we check the entire AC system, if there are any parts that need to be replaced, we’ll let you know about them.  Our trucks are stocked with almost every part you need for your AC to get back up and running properly the same day.

If your system is running well, we get right to work washing your AC.  Many air conditioning manufacturers are switching to materials like micro-channel which can’t be washed with soapy or chemical solutions, and we pay attention to things like that.  If you have a dog that runs around in your back yard, we try not to use soapy solutions that drain into the area around the AC, so your best friend doesn’t get sick.  We are so thorough cleaning the AC, it’s not uncommon to see a tech vacuuming out your AC to get rid of the sticks and other debris that can be a nuisance to a healthy air conditioner.

What’s the Benefit?

When the air conditioning tune-up is complete, you’ll have peace of mind knowing that your system is in tip-top shape.  Making sure a professional completes these steps every year will really pay off in the later years of your HVAC system’s life.  As a technician, my 20-year-old system is so clean, it runs like a champ.  It’s old and loud, but it keeps my house cool just fine!  Even on 105-degree days.  Why?  Because I take care of it.  If you’re curious and would like to learn more about how your air conditioner works, check out my blog post on this topic.

So, give Fox Family a call here in Sacramento County, the Foothills and the Mother Lode.  We would be honored to service your HVAC system in 2019!

Thanks for checking in on our blog.  See you next week!

Greg

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Which Whole House Fan is Better, QuietCool or Triangle?

quiet cool whole house fan

What Whole House Fans Do

Are you the type of person who likes to open their windows at home?  Whole house fans are mounted in your ceiling and are used to pull cooler air from the outside of the home to the inside.  By opening your windows around the house, the whole house fan will allow air outside to come in.  This way you have fresh air coming into your home, as well as equalizing the temperatures outside and inside.  The second benefit of a whole house fan is that it cools off your attic, so the entire home can perform better, and save you energy.   Don’t confuse these with attic ventilating fans that mount on the gable vent in your attic and point outwards to vent the attic.  The difference here is, a whole house fan will complete this process much faster and probably lower the temperature in your attic more than an attic fan will.

Fox Family carries two types of whole house fans, the QuietCool brand and Triangle brand.  We love them both, but for different reasons, and people usually find themselves really liking one or the other.

QuietCool is a brand that has stormed the industry with innovative thinking and low energy usage fans.   They started up in 2003 out of Temecula, California.  Triangle Whole House Fans are the more traditional style fans.  They are a little bigger and might run at a little higher decibel rating, but they move a ton of air very quickly.  We’ll talk more about that later.

Getting straight to it, I want to point out the features of both fans, and then let you decide which one is best for your home.

QuietCool Fans

The first whole house fan I got for my home was a QuietCool whole house fan.  I was drawn to it because as an HVAC technician, I liked the idea of attaching a flexible duct to the grille that you see in the hallway and placing the fan on the other side of the 10 ft duct.  This insulates the sound of the fan.  QC offers different capacities of fans and a very useful and easy to use sizing formula featured on their website.

The formula on the QuietCool website suggests sizing a system for between 2 and 3 cubic feet per minute, or CFMs, per square ft of your home.  This means if your home is 1,000 sq ft, you’ll want a system that can move between 2,000 and 3,000 cfms of air.  You can then proceed to check out different models and find the Trident Pro 2.5 and Trident Pro 3.3, both of which will move 2,500 to 3,300 cfms of air.

The technology I like about QC fans is in the insulated damper that shuts off any access to the attic when the system is turned off.  This also prevents heat from the attic from coming into the home when the fan is turned off.

In 2011, QuietCool became the first to incorporate ECM motors with the fan.  These motors run quietly and at lower amperages than regular PSC motors.  PSC motors are the ones that you’ve seen on traditional whole house fans since the 1960’s.  They require a capacitor to run properly.  If the capacitor fails, the motor won’t work, and you’ll have to replace the capacitor before the motor will work again. ECM motors are electronically commutating motors.

QuietCool ECM Motors

A point I want to make here about speeds.  In studying the QuietCool ECM motors in the Stealth Pro line, I found that they operate better at lower fan speeds.  A case in point is with my own two-story, 2200 square ft home.  I installed the 1.5 Trident Pro in the master bedroom ceiling, near the door.  I put a 3.3 Trident Pro at the top of my stairs on the second floor.  (See the link at the end of this post to watch my installation video.)   When I turned them on for the first time, I wasn’t really happy with the volume of air it was moving.  It was nice but, I guess I was looking for more.

Since then, I always recommend to people they get the biggest one they can afford and use the 3-speed switches provided by the manufacturer and adjust the airflow accordingly.  You’ll find that the motors run more efficiently at lower speeds.  Okay, point made about QuietCool’s volume issues.  I’ve mentioned it a few times before.

Triangle Whole House Fans

When you mention traditional style whole house fans, people think about loud, whirring helicopters rumbling in their homes.  And QuietCool does a good job of making that point on their website.  But let’s look at an American classic, the CC Series of Triangle Whole House Fans.

As a technician working in hot attics, I noticed how much more air these traditional style whole house fans seemed to be moving.   In fact, we’ll turn these whole house fans on during hotter days so we can bring the temperature of the home up into the attic, which is at times 30-40 degree warmer!  And the homeowner has fresh ambient temperatures coming into the home.

The blades are larger, thicker and more durable than QuietCool’s.  The belt drive is the secret to its quiet nature.  The motor sits on top of the frame instead of near the ceiling joists.  This reduces the vibration and noise from the fan blade.  You really have to hear it to believe it.  (See the link at the end of this post to watch my installation video.)  All the noisy traditional style fans I’ve seen were old — maybe 15 years or older – some even older!  By choosing a new quality-built fan, not some big box store whole house fan, you’ll feel and hear the difference in sound and volume of air once it’s installed.  Think of these as luxury cruisers of the whole house fans.

How Much Air Do They Really Move?

QuietCool fans are sized in 1.5 for 1500 cfms, 2.5, 3.3, 4.8, 5.5, 6.0 and 7.0 models.  So, 7000 cfms is the max you can get from a QuietCool fan.  Triangle fans are sized in 24”, 30”, 36” around here.  They do have a 42” and 48” but we don’t have them around here.  The most common 36” fan moves over 9700 cfms of air, almost 3000 cfms more than QuietCool’s biggest fan.  That’s pretty impressive to me.

Where Are They Installed?

Both of these fans are ceiling mounted.  The triangle fan is mounted on top of the ceiling joist in the attic, bringing the fan blade further back to reduce noise, with no cutting involved.  The QuietCool fans can also be installed between the ceiling joists without having to cut anything.

Most people don’t create a whole new dedicated circuit for these fans, instead, it’s more typical to tie into the existing HVAC circuit for the furnace.  This is because nobody runs both the whole house fan and their furnace or air conditioner at the same time.

DIY or Contractor?

The best DIYers can install these themselves.  A little electrical knowledge about switches and proper ventilation of the attic will go a long way installing these.  Be sure to check out the card at the end of this video if you’d like to see an install.  If you do need a little more help with installing a whole house fan here in the Sacramento area, we’d love to be the company that gets to do that for you.  And if you’d like to learn more about how whole house fans work, you can also check out my post What is a Whole House Fan?

A Word About Warranties

The QuietCool Systems come with a 15-year warranty.  Triangle Whole House fans only offer a 1-year manufacturer’s warranty.  So that’s kind of lopsided there.  QuietCool says they will replace any part that fails for the warranty of that system.  When I searched the website of Triangle Engineering, I couldn’t find the warranty info on the whole house fans, although they confirmed their warranty by phone.

What do you think?  Have you seen or heard these older style fans?  What do you think about them?  And what do you think about QuietCool’s fan?  Is it strong enough?  Let me know what you think in the comments below.

Thanks so much for tuning in this week on our blog.  See you next week!

Don’t miss our video on this topic:

See also

Installation of a Triangle Whole House Fan
https://youtu.be/qICIrdBGIz8

Installation of a QuietCool Whole House Fan
https://youtu.be/du1K7b4gaE0

How Solar Works

Have you ever wondered how solar works?  On this blog, we’re going to discuss what it takes to make the sun’s energy produce AC voltage for your home.

Since the early 1900’s the United States has spent a crazy amount of money on the current infrastructure.  This infrastructure supports mining, drilling, transporting, refining and distributing fossil fuels for our use.  At the same time, the demand for energy has gone up steadily with the population.  In the US, we get the majority of our power from coal, oil, and natural gas.  Solar, Wind, Hydroelectric, and other renewables are starting to make a dent in the infrastructure, however.  I think there is definitely hope for renewables in the future as a primary source of energy.

It’s hard to believe that the Earth absorbs over 173,000,000,000,000,000 watts of energy.  That’s 173 thousand terawatts in a day, 10,000 times more sun than we need on any given day.  Did you know 20 days of sunshine is all Earth needs to produce more energy than all the fossil fuels ever did on this planet combined?

Transforming light from the sun directly into electricity without any moving parts is science!  It’s free, and when it’s not we won’t care, right?  So how do we harness that potential energy and power our homes with it?  It’s a process as predictable as the sun rising and setting every day.  And there are no moving mechanical parts during the whole process.  This makes solar technology so desirable because the technology will last for decades at a time.

So how do we take photons from the sun and get them to push the electrons on the solar panel in a manner that will create enough electricity to power our homes?  It all starts with the PV cell.  A single PV cell is the smallest component capable of this process.

The Perfect Element

Silicon solar cells are the most common type.  Silicon, being the second most abundant element on earth, is perfect for this.  The silicon is then sandwiched between two layers of conductive material.   An atom within the silicon connects to other atoms with four strong bonds.  This keeps the electrons stationary, so no current can flow.

A silicon PV cell is a semiconductor with two main layers, a positive and a negative.  The positive side is doped with boron to give it a positive charge or extra electrons, and the negative side is doped with phosphorous to give it a negative charge.  The junction where the positive and negative layer come together is called the P-N junction, and an electric field is created there.  It generates a half (0.5) volt dc potential to travel through the cell from the P layer to the N layer, but not in the other direction.   The connection between the P layer of one cell and the N layer of an adjacent cell increases the overall voltage, which is added in series.

Tapping Sunlight

Sunlight has particles of light shooting out from it, called photons.  When a photon hits the solar panel hard enough, it knocks an electron from its bond, leaving a hole. The negative electron and location of the positively charged hole can then move around freely.

Since there is an electric field at the P/N junction, the electrons will only go one way.  The electron gets pulled over to the N-side, while the hole gets pulled to the P-side.   From there, this process repeats itself and does work like powering the house until the electrons return to a conductive aluminum sheet on the back of the panel.

Because the voltage of an individual crystalline PV Cell is only 0.5 v dc, a PV module consists of numerous cells, wired together in series.  So, when 36 cells are wired in series, you should expect to get 18 volts DC.  Unlike voltage, the current of the cell is dependent on the surface area, so the larger the panel the more voltage it can produce.  In general, though, the current of each cell will be the same as the current of each module.  The panels of yesterday were 18 and 36 cell panels.  In 2019, our panels are 60-cell at the very least and go to 72 and 96 cell panels for the residential market.  More cells mean more power per panel.

Monocrystalline vs Polycrystalline

Monocrystalline and Polycrystalline panels are your choices for your solar panels.  Because of their efficiency and aesthetics, Monocrystalline panels are currently the most desirable. Typically a black panel and frame, these are made with a single type of crystal.

The single crystalline material used on Mono panels makes them more efficient than polycrystalline panels.  They’re more efficient because they allow the electrons to move more freely.  The reason they’re a tad bit more efficient than polycrystalline panels is due to the casting process of the cells.

Polycrystalline panels are made with a variety of crystals.  So when the molten silicon of multiple types of crystals gets poured into the mold and solidifies, it dries flat into what looks like a bed of flakes or crystals.  Polycrystalline panels have a bluish tinge to them too.

The different crystals within the cell create grainy speedbumps that can make it more difficult for the electrons to navigate out of the cell.  Monocrystalline panels are smoother at that level.  That’s the reason Monocrystalline panels are all the rage right now.

Going Solar

I hope this has helped you gain a little understanding of the process of solar energy production.  If you’re in the Greater Sacramento area and interested in having Fox Family come out and give you a quote on your solar project just give us a call, or you can text us, too, at 916-877-1577.

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