Troubleshooting Single Zone Rooftop Units
SER 143

The Troubleshooting Single Zone Rooftop service course is for technicians servicing Carrier Single Zone rooftop units This training course covers commercial rooftop units 25 tons and under, and deals with the industry’s most common packaged products. The class provides detailed training intended to improve the troubleshooting skills and product knowledge of HVAC technicians. A variety of rooftop units and simulators are used to provide training exercises for wiring diagram interpretation, compressor troubleshooting, and control/sensor troubleshooting. The course specifically covers Carrier rooftop units produced over the last 20 years, however, many procedures covered can be universally applied to all makes of rooftop units. Specific models covered include 48/50 T, H, P, L and K series units 25 tons and under. These models cover electric/electric, gas/electric and heat pump units primarily as applied in constant volume applications. At the end of this course a student will be better able to quickly diagnose and repair refrigeration, gas heating, heat pump, economizer, air side and system operation problems on these units. The class addresses electromechanical (E-M), ComfortLink, PremierLink™, and the RTU-OPEN™ Control systems and their operation. The class also addresses staged air volume, ECM and VFD applications, Humidi-MiZer Adaptive dehumidification system, EnergyX heat recovery, and various economizer options used with these units. The course also covers the 48/50LC*B multi-zone variable air volume unit. This class is a mix of classroom training and in-lab exercises on actual rooftop units. Over 30% of the class involves lab exercises on actual operating rooftop units.

Who should attend this training

This course is for HVAC technicians with a minimum of one year of field experience or a graduate of an HVAC training program. Students are expected to have basic math skills and a basic understanding of HVAC tools (gages and digital thermometers) and troubleshooting equipment.

Learning Objectives

At the conclusion of this course each student should be able to:

• Identify by sight various types of SRTs (Small Rooftop Units) , their options accessories and functions
• Use the literature to find installation requirements and using the checklist confirm operation at start-up
• Use a 48TC with E-M controls and with or without economizer: identify components, use the sequence of operation, and troubleshoot unit operation. Also be able to do the same on 50TCQ heat pump
• Identify and locate all the control components for a 48LC with E-M Controls, the sequence of operation, and troubleshoot units with and without economizers
• Identify controls as E-M, ComfortLink, PremierLink, and RTU Open and demonstrate their function used to control operation and for unit start-up
• Explain ECM and VFD operation in Staged Air Units
• Name the specific components of a Humidi – MiZer unit, their function, and in turn be able to start-up and troubleshoot this option
• Explain components of an EconoMi$er X unit, their function, and in turn be able to start-up and troubleshoot this option
• Explain the components, function and operation of the EnergyX heat recovery option
• Describe the sequence of operation and system differences with the 48/50LCB Variable Air Volume (VAV) units
• Identify the metering devices and the procedures to check and adjust the charge for the single zone units
• Use the standard start-up and maintenance procedures and describe where to find them

Training Methods Used

This course uses a combination of classroom lecture, videos, animations, tours in the training facility lab, demonstrations, practical labs on operating equipment and workshops to present the material. Student’s achievement of the learning objectives is determined by successful completion of the workshops, labs, homework, and final written and practical exam. Workshops are instructor guided exercises using the procedures taught in the lectures.

Topics Covered

All times are approximate and shown as (classroom hours/lab or workshop hours).

• Rooftop introduction, types, models and components (1.5/0)
• 48TC Electro-mechanical controls (1.5/1.0)
• Control terminal boards with Cycle-Loc (1.0/0.5)
• Gas heating with IGC (1.0/0.5)
• Heat pump with defrost board (1.0/0.5)
• Homework (0/0.5)
• 48/50LC with SystemVu™ controller(1.0/0.5)
• 48/50HC with ComfortLink control (1.0/0.5)
• RTU Open controller (1.0/0)
• Economizer 2 and IV (1.0/0)
• Rooftop unit electrical faults lab (0/3.0)
• Homework (0/0.5)
• Psychrometrics and airside lab (1.5/ 1.5)
• Humidi-MiZer (1.5/0) EnergyX (1.5/0)
• Electro-mechanical controls lab (0/3.0)
• Homework (0/0.5)
• EconoMi$er X (1.0/0)
• Staged air volume (1.0/0)
• 48/50LCB VAV unit (1.0/0)
• Rooftop refrigerant charging (1.5/0)
• Refrigerant charging lab (0/3.0)
• Homework (0/0.5)
• ComfortLink controls lab (0/2.5)
• Start-up and maintenance (2.0/0)

Completion requirements

To receive a certificate for this course student must be present for the entire course, complete all workshops and labs and receive a grade of 70% (C+) on graded labs and homework.

Certifications

This class is approved for 3.5 IACET CEU’s and 35 NATE CEH’s. A certificate of achievement indicating your successful completion and appropriate continuing education hours is issued at the end of class. NATE hours are submitted at the conclusion of class provided you supply your NATE ID number.

Prerequisite requirements

None.

Suggested background

For technicians with limited troubleshooting experience, this course is most effective when preceded by the Pro-Electrical (SER027) and Pro- Mechanical (SER028) classes. These classes teach troubleshooting procedures and the use of test equipment the background of which is assumed for this course.

Materials to bring

No special equipment is required we provide the appropriate safety equipment required by Carrier. Arc flash equipment is not required for the voltages used in the lab, if you are required by your company to use other PPE you may bring that to class.

What you will receive

Students in this course receive a course workbook, Carrier Service Procedures handbook, safety gloves and goggles, charging calculators, and PT cards.

Appropriate dress for this class

This class has a number of exercises that take place in the lab on operating units; participants should wear long pants, closed toed shoes and appropriate shirt, long or short sleeve. If your employer requires special dress which is more stringent than these requirements, this dress should be worn.

Class hours

Class starts at 8 AM Monday and runs from 8 AM till 5 PM each day including Friday. Travel arrangements should be made accordingly.

Location & lodging

Carrier University is located at 5900 Northwoods Business Parkway, Charlotte, NC 28269. Lodging options can be found here.