The NEC and HVAC Chapter Two - Chapter Two of the National Electrical Code (NEC) covers Wiring and Protection and starts at Branch Circuits, Feeder circuits, GFCI requirements and protection. An HVAC installer may want to pay attention to branch circuit requirements. Article 220 in Chapter two of the NEC includes calculations for branch and feeder circuits including service calculations. (Table 220.3) (more…)
Basic Electric Circuits for HVAC - If you are new to electricity and want to learn you need to start with the fundamentals of electricity first. Included in the basics of electricity and the primary lesson in electricity is electrical safety. Electricity can be very dangerous and safety needs to be practiced. Electricity is invisible to the eye and can only be felt when touched. (more…)
Air Handling Unit Components 2: Heat - There are many different types and arrangements of heating systems for air handling units and these types of heating systems and arrangements of heating systems vary from commercial to residential. Some air handling units do not have any heat source inside them at all but have remote heat for zoning. The air handling unit provides the airflow and the remote heaters provide heat for zoning.
Sometimes the air handling unit is a VAV air handling unit and other times it is just to provide air for a duct heater whether the duct heater is gas-fired or electric. For air handling units which some have heating systems inside the five main ways of providing heat for air handling units are:
Grounding and Bonding Electrical Systems | NEC Code - National Electrical Code Article 250 is all about grounding and bonding as represented in this photo where electrical systems are grounded and bonded to the buildings steel structure.
There are many different rules in the NEC (National Electrical Code) pertaining to grounding and bonding because grounding and bonding are important for safety reasons. Electricity will take the path of least resistance so if there is a short in the system the grounding system will be the path for the electricity instead of the motor or load that experiences the short. (more…)
Common Sense Safety HVAC Codes - Some HVAC Installation technicians take pride in their work and make any installation job they perform look like a work of art. There are others who don’t care and want to install the unit as quickly as possible and move on down the road to the next job so they can do the same.
It really does not take much more time to do things right in the first place including reading the instruction manual that comes with every new condenser or air handler (actually all new HVAC equipment comes with instructions for installation). (more…)
Chapter Three NEC and HVAC - Chapter Three in the NEC covers Wiring Methods which includes how the wiring is supposed to run, the conduit for wiring, outlets, junctions, and switch points, and a host of other topics about the proper way to run wiring.
HVAC Technicians will be familiar with piping support as is required in the Mechanical Code and electricians must follow some of the same rules when running conduit and add support for the conduit. (more…)
HVAC Mechanical Code Overview - Many people unfamiliar with air conditioning and heating do not know that the mechanical code regulates air conditioning and heating system installation in many municipalities. (more…)
Wire Type and Sizing Considerations - When a professional electrician looks at a job to wire a house or a new circuit in any structure the primary consideration in the wiring job is the size and type of wire to be used for the job per the NEC. The same for a plumber when looking at a job the plumber will size the pipes based on the number of gallons needed to carry the proper amount of water to its destination. If the pipe is too small then the water needed will not reach its destination. This is almost the same for electrical wire except under-sizing electrical wire is dangerous. (more…)
