Technical Training
It’s Not Your Father’s Air Conditioner!
Your Instructors:
◊ Don Fort
◊ Courtney Gardner
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing
new age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future …
Closing Remarks with Q & A
Thanks for Coming !
3
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing new
age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future …
Closing Remarks with Q & A
Thanks for Coming !
4
Reciprocating Compressors
Suction
Discharge
Back when I had
Teeth, this is
what I Cut them
On!
Why Change?
Reciprocating Compressor
Scroll and Rotary Compressors
Rotary Compressor
Why Are
Manufactures
Moving Away
from
Reciprocating
Compressors?
• Not as efficient as rotary or scroll
• Reliable speed control more
difficult
Scroll Compressor
Fixed Speed Compressors Control
Scroll Compressor
OK.. Good Point about
compressor efficiency But…
what’s wrong with potential
relays & good old contactor
circuits?
Variable Speed Compressor Control
Rotary Compressor
Scroll Compressor
Inverter PCB
• In a word… INVERTER
• Translates into reliable and
efficient speed control
• Less dependence on electromechanical control devices.
Variable Speed Compressor Control
Control stages of the average inverter drive PCB
1 ᶲ AC 60 Hz
Variable Speed Compressor Control
IGBTs gate at a maximum rate of 9,000 times per second!
IGBT
Insulated Gate Bipolar
Transistor (IGBT)
Gating this electronic switch is fast
and the control characteristics are
very stable and switching can take
place at a very high rate of speed.
This provides the type of DC pulse
width modulation necessary for
simulating the three phase AC
sine waveform.
3 ᶲ AC, Variable Hz
Pulse Width Modulation
3 – Phase
Variable Speed Compressor Control
Simply put the IGBTs are just single pole switches…
Variable Speed Compressor Control
Richard Mollier (1863 to1935,) was a Germen professor of Applied
Physics and Mechanics. A pioneer of experimental research in
thermodynamics.
Mollier diagrams (enthalpy-entropy charts) are routinely used in the
design work associated with power plants (fossil or nuclear),
compressors, steam turbines, refrigeration systems, and air
conditioning equipment to visualize the working cycles of
thermodynamic systems.
Old Thermostatic Expansion Valve
OK.. Great Point
about compressor
control But… what’s
wrong with a good old
TXV metering device?
Liquid
Refrigerant
Why Change?
Linear Expansion Valves – LEV (EEV)
 More precise control of refrigerant flow. Many LEV
valves pulse between 3000 & 4000 times per second!
 No mechanical superheat adjustment required
 Temperature sensors are generally not insulated
Temperature Control
Alright! But… I know I
can hold on to my
Honeywell T87
Thermostat… Right???
Well you Could
Just Not
Responsive
Enough!
Why Change?
Better Temp Control - NTC Thermistors
Resistance
NTC Thermistor Resistance
vs. Temperature Curve
IDU Piping Circuit Showing
Thermistor Locations
Temperature
Tight temperature control is possible
due to the deployment of 3 ranges of
NTC Thermistors:
• Pipe (Low temp) 5K
• Air (medium temp) 10K
• Discharge Pipe (high temp) 200K
Refrigerant Pressure Monitoring
Well I get the fact that high
SEER equipment has to be
electronically controlled but I
just have to use my manifold
Gauges to determine proper
operation… Don’t I ???
Why Change?
Refrigerant Pressure Monitoring
Capacitive Sensing Element
As the pressure varies, the diaphragm
flexes and the distance between the capacitor
plates changes. This ceramic sensing element
design produces a variable capacitance that is
highly stable and reliable.
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing new
age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future …
Closing Remarks with Q & A
Thanks for Coming !
19
Basic Refrigeration Cycle Is the Same
mm
Click for Animation
Basic Components are the Same
VRF Technology Allows True Heat Recovery As Demonstrated Here
mm
Play
Animation
Basic Cycle - the same, Control Complex
Modern VRF (Variable Refrigerant
Flow) Air Conditioning system are
dynamic in that they flex capacity
to meet a wide range of ambient
conditions. The control systems
for this type of air conditioner must
monitor the following:
•
•
•
•
•
•
•
•
•
Suction pressure
Suction temperature
Discharge pressure
Discharge temperature
Inverter Compressor Hz
Condenser fan speed
Sub-cooler superheat
Main LEV operation (ODU)
LEV operation for individual
IDUs
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing new
age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future …
Closing Remarks with Q & A
Thanks for Coming !
23
Troubleshooting With Software…
As seen from previous slides a very
large amount of data is collected and
managed by modern VRF systems.
This is transmitted via RS-485 protocol.
The only way to track system operation
is through computer software.
PRCTFE1 module
Troubleshooting With Software…
Computer needed to analyze system operation
Main View (Target Value)
ⓐ
Current value / target of system
ⓑ
ⓒ
ⓓ
ⓔ
Current value
(Only Plus III)
Cycle View (Current value)
①
②
Only Plus III
Only Plus III
Troubleshooting With Software…
A computer is needed to analyze system operation
Troubleshooting With Software…
Coming Soon … A Blue Tooth Troubleshooting Tool
Connection
Blue
Blue
tooth
tooth
Android Smart phone
Cable
Inverter ODU
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing new
age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future … & the future is NOW!
Closing Remarks with Q & A
Thanks for Coming !
28
Multi Zone Systems
MULTI V (up to 32 zones pre piping module)
Agenda
Welcome & Introductions
Basic Component Changes – Why Change?
What Connections can be made by instructors when introducing new
age technology?
Service & Troubleshooting – How has this been enhanced?
Catch the Wave of the future … & the future is NOW!
Closing Remarks with Q & A
Thanks for Coming !
30
Points to Take Away From This Presentation
• Although the Refrigeration Cycle has not changed, the
way we manage the process has changed a great deal
• Modern components call for modern means of control
and troubleshooting
• Linkage between the refrigeration process that we all
have taught for years and new age technology must be
made in order to attract the next generation of HVAC
professionals to our industry.
• Keep an open mind with a view to incorporating VRF
technology into your Future curriculum.
Points to Take Away From This Presentation
For More Information
Check Us Out At
www.lg-vrf.com
Thank you.