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Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in Plano, Allen, and Frisco.  We service all homes in southern Collin and Denton Counties with no travel charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.

This Is Part 2 of a 3 Part Article:

  • Part 1:   Furnace Control Board – Purpose And Functions
  • Part 2: Furnace Control Board – Power Surge Protection + Surge Protection For The Rest Of The House
  • Part 3:   Furnace Control Board – Other Ways To Help Minimize Early Failure.

For Part 1 Of This Article, Click HereAlsPlumbing.com Furnace Control Board – Part 1

Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance and repairs for all brands of Central A/C, Furnace, & Heat Pump.  Additionally, Al’s sells & installs new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).   Al’s also provides repairs & replacements for every plumbing component in your home.

Call Al’s today to discuss any concerns or problems you are having with your HVAC System or Plumbing.  We can arrange an appointment to meet your schedule.  We also provide 24/ Emergency Service.

How Electrical Current Flows Through Your Home

How Current Flows Inside Your Home:

  • The “Hot” Wire (black) carries 120 Volts current TO electrical devices.
  • As the device uses the current, it becomes (used),  Zero (0) Volt current.
  • As the current is used, it flows from the Hot (black) wire into the Neutral (white) wire.
  • The Neutral Wire (white) carries the (used), Zero / 0 Volt current FROM devices.
  • The 0 Volt current travels back to the home’s circuit breaker panel — then back to the electricity distributor’s neighborhood transformer.
  • The transformer re-energizes the current back to 120 volts and sends it back into your home.

How Your Home Deals With Small, Internal Power Surges

The Additional Purpose Of The Neutral Wire:

  • The Neutral Wire also carries Excess Live Electricity away (120 Volts) — when electrical devices turn off.
  • Until the neutral wire has carried away the excess current, A Power Surge Is Occurring.
  • When live 120 Volts excess current returns to the circuit panel.  That current moves into the ground wire and is diverted into the earth.
  • Excess current is 120 Volts, so it can’t go back to the neighborhood electrical transformer.  The transformer can only accept 0 volt current.
  • This type of small, recurring internal power surge degrades electronics & electrical devices over time

Why Internal Power Surges Occur

When a high electricity-demand device turns off, you often will see lights become brighter for a moment.  The period of time the lights were brighter was a small, internal power surge (called a “swell” in the diagram above).  “Internal” means the power surge came from within the house.

When the device turned off, there was no where for the current it was using to go.  That excess current traveled (in the neutral wire) back to the ground wire (inside the circuit breaker panel) and into the earth.   This type of small, recurring internal power surge degrades electronics & electrical devices over time

 

What Happens When A Short-Circuit Occurs In Your Home

** Definition Of A Short Circuit:  When a new circuit is formed, causing current to go through the unwanted circuit, instead of the normal circuit.  The unwanted circuit has lower electrical resistance because it’s shorter than the normal circuit (hence the name “Short-Circuit”).  Electrical current always takes “the path of least resistance”.

The Purpose Of The Ground Wire In Your Home (beige color in photo above):

  • The Ground Wire (beige) is there to divert any live / 120 V current caused by a short-circuit**  This current is also diverted into the earth.
  • Short-circuit current is 120 Volts, so it can’t go back to the neighborhood electrical transformer.  The transformer can only accept 0 volt current.

NOTE: When your receive an electrical shock, you became part of a Short-Circuit”.  The current went through you, instead of the normal circuit.

 

Since 1962, Homes Have A Ground Wire To Prevent Electrical Shocks

In order for you to receive an electrical shock, there must be 2 points of contact on your body (1 for current to enter & 1 for current to exit).  You may think you can’t get shocked by touching a single wire (you can if you touch the “hot”/ black wire).  Because we are standing on the ground, if we make contact with a “live” wire, we complete the circuit and the electricity flows through us, then into the earth.  To prevent this, one side of a home’s electrical system is connected to an earth-ground (in homes built since 1962).

  • The Ground Wire (beige) provides a primary path for Live, 120 Volt electrical current to move safely into the earth.
  • If a short-circuit occurs, the Ground Wire carries large amounts of  current away and into the earth.

Since 1962 the National Electric Code (NEC) requires every electrical outlet must be grounded (homes built before 1962 were not required to have grounded electrical outlets).

The outlet’s right vertical slot (the smaller slot) is connected to the “hot” wire.  The left vertical slot connected to the “neutral” wire (the larger slot).  The rounded top hole is connected to the ground wire.  Both the neutral & the ground wires are connected to a ground wire located inside the circuit breaker box.  During normal conditions the ground wire never carries electrical current.  It’s there as a safety feature, to provide an efficient path for current flow away and into the ground wire (then into the earth).

Three pronged electrical cords add an additional source of protection from electrical shock.  Grounding is to prevent electrical devices and appliances from shocking their user.  Their metal case is connected directly to their ground prong.  If a short circuit occurs, the separate ground wire takes the current away.

 

Why Some Electrical Devices Have A 3-Prong Plug, And Others Have A 2-Prong Plug

Electrical devices are rated Class 1 or Class 2.  A product’s classification is determined by its ability to present a dangerous shock to a user.

If an electrical-fault occurs, the external metal cover / case of an electrical device will become “live” with electricity.  If the metal cover / case isn’t grounded, and someone touches the device, current will travel through their body into ground.  If conditions are wet or damp, or they are outdoors, they are more likely to experience a severe shock.  For this reason, any device with an outside cover / case that will conduct electricity must have a grounded / 3-Prong plug.

SAFETY NOTE:  If using an extension cord with a 3-prong electrical plug, the extension cord must also be a 3-prong.  Using a 3-prong device on a 2-slot extension cord does not offer grounding protection against severe electrical shock.

SAFETY NOTE: If the 3rd prong has been removed, that electrical device is unsafe to use.  Replace the cord with one that has a 3-prong plug.

Class 1 Electrical Devices:  Have Basic insulation + a ground plug for protection. Their metal case is connected directly to the ground prong.  EXAMPLES: Toaster, Iron, Microwave Oven, Electric Heater, Refrigerator, Freezer, Washer and Dryer, Power Tools (with a metal outside cover).

Class 2 Electrical Devices.  If an electrical device is covered in a non electricity-conductive material, the device is “double insulated” and does not require a grounded plug.  EXAMPLES: TV’s, Stereos, Hair Dryers, Lamps and Lawn Power Tools (with a plastic outside cover).

Guarding Against Power Surges Requires A Three-Stage Approach

Electrical devices are designed to handle specific voltages. Power surges are instances when devices are subject to higher voltages than they are designed for. Generally speaking, the larger and longer the surge, the greater the potential for damage.

  • Sudden, severe power surges (like those resulting from lightning) typically cause nearly immediate and total failure of electronic devices.
  • Minor, recurring, internal surges do not cause immediate failure, they are known as a “silent killer” of electronic devices.  These surges gradually degrade internal circuitry (inside the circuit boards, such as a furnace control board) until it eventually fails sooner than it would have if it had been protected from power surges.

There Are 3 Levels Of Surge Protection For A Home

  • Whole-House — to protect from large, external power surges entering the home.
  • HVAC System — to protect the HVAC System components from both external + internal surges.
  • Individual Circuit (plug in) — to protect electronics & appliances.   These protect from smaller, recurring inside-the-house (internal) surges + large external power surges.  If you have a whole-house protector, you still need individual circuit protects to guard against internal power surges.

Note:  220-Volt surge plug-in protectors are also available.  Click Here For More Details: 220-Volt Surge Protector

Note:  Installing 2 HVAC Surge Protectors (1 for furnace + 1 for a/c outdoor unit) is far less cost than replacing a furnace control board, or an a/c outdoor unit’s compressor due to being damaged by an external power surge.  The surge protectors will also prevent premature wear & failure caused by internal surges.

Whole House Surge Protector

NOTE: Whole House Surge Suppressors Must Be Installed By A Licensed Electrician.  Al’s Does Not Sell Or Install Them. 

 

HVAC System Surge Suppressors

Protect Furnace Control Board + Outside A/C Unit From Power Surges With Surge Protectors

** Al’s Plumbing, Heating & A/C Sells And Installs HVAC System Surge Protectors (we install only what we sell). **

Damage To HVAC System From External Power Surges

An large external power surge often results in an immediate HVAC System breakdown.  A large enough external power surge has the capacity to destroy HVAC components.  HVAC Systems’ warranty does not cover damage caused by power surges (the breakdown is due to damage).  Some homeowner insurance policies cover lightning damage.  The burden prove lightning caused the damage is up to the owner.

Recurring internal power surges cause ongoing degradation of electrical devices.  A furnace control board that failed long before it should have was likely becoming damaged from recurring small internal power surges, or was damaged by one external large power surge.

NOTE: Your central a/c turns off before the furnace.  This allows the furnace to continue moving air until its internal parts warm up (this is an energy-saving feature).  Residential central a/c ranges from 1 to 5 tons (3 tons for 2,000 square foot home).  Electricity use is 3,500 watts per 1 ton of cooling capacity (1 ton = 12,000 BTU’s).

The higher an electrical device’s electricity usage, the larger recurring internal power surges it creates.  Each time the device turns off, there is excess electricity within the electrical wiring that must be moved to the ground wire.  The furnace is exposed to a power surge each time the a/c turns off.  Central a/c cycles many times during a 24-hour period.

With Furnace + A/C surge protectors, they route excess electricity directly into the ground.  The power surge never reaches the home’s wiring or other HVAC components.

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Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in Plano, Allen, and Frisco.  We service all homes in southern Collin and Denton Counties with no travel charges.

Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience and offer 24/7 Emergency Service.