Title: Unit 9 Outline
Course: HET 230 - Spring 2015 > Section: HET 230 - Spring 2015

Unit 9 Outline

Unit 9 Outline
Unit 9 Outline

Introduction:

Last week, we discussed V-Belts and Fan Accessories.  Understanding the relationship between the drive and driven sheaves is important to know when dealing with belt-drive fan units.  Getting this correlation correct is important for proper airflow and static pressures with in a duct system.  It also is important for reducing potential electrical and mechanical problems to drive motors over time.  A skilled technician needs to be familiar with the proper motor, belt and sheave calculations in order to understand this mechanical relationship, for the application they are working on.   In addition, they must understand the fan accessories available for safety and noise reduction, which leads us into this week’s subject matter.

This week, you will learn about identifying fan problems and the proper maintenance procedures, including common vocabulary terms.  As always, you will be provided a PowerPoint a presentation and weekly study materials, you will also participate in weekly discussions and complete all assignments, including a content assessment quiz.  It is important to plan a proper Preventative Maintenance Schedule (PMS).  Such PM’s are performed daily, weekly, monthly, semi-annual, or on an annual bases.  Whatever the manufacturer suggestion, would be the proper schedule to follow.  One of the most important aspects of a daily walk-around is to identify potential problems, using the “Law of Sixes,” in between routine scheduled maintenance.  One should understand their limitations while diagnosing potential problems, and should confer with specialists to clarify potential issues beyond their abilities.  Up until this week, our primarily focus has been on learning calculations, procedures, duct design specifications, airflow in ducts and fans laws and drives.  A knowledgeable technician creates a general sense of potential problems through experience.  One knows that they can see and hear how to diagnose the problem, and safely fix the problem through followed procedures.  Learning these subjects will allow you to form a solid foundation for executing the upcoming six projects for the rest of this class, beginning with Project 1, Heat Loss.

Objectives:

On completion of this week’s assignments, the student should be able to:

- preform all safety planning procedures such as Lock-out/Tag-out, potential voltage check and blocking procedures before staring any work
- understand proper walk-around checks to look for obvious causes, using the “Law of Sixes”
- understand their limitations when it comes to their ability to identify and resolve issues; they may require a design specialist to provide assistance
- identify symptoms and causes relating to Air Delivery, Air Noise, and other Noises related to Vibration
- understand other forms of vibrations such as Resonance and Sympathetic Vibration
- understand and identify various situations that include Fan and Motor Vibration, including Fan Wheel problems and System Noise and Vibration noises
- identify Air Noises such as Fan Surge, Velocity too high, Damper position, and Duct Sizing problems
- recall all safety procedures while working on blowers and motors, and in plenum spaces
- understand that his/her actions can affect others while working on this equipment
- identify and practice good maintenance procedures such as inspection checklists and schedules, proper component lubrication, and completing proper logbooks