Transcript Generic Service Preso

ECM-Driven Systems
Industrial Systems
How’s the GE ECM™ Motor different than an Induction Motor?
• Operation
• Construction
• The ECM’s Electronics
The ECM's Benefits and Advantages in HVAC
• Efficiency
• Constant Airflow
• Tailoring to the Customer
• Sound
• Programmability
Installation and Serviceability
• Troubleshooting ECM-Driven Systems
• Set-up
• Replacing the Control Module
• Troubleshooting Guides
• Frequently Asked Questions
GE ECM Motor is a trademark of the General Electric Company
ECM-Driven Systems
Industrial Systems
What's an ECM?
The highest efficiency motor there is! … A DC Motor
 Without mechanical Brushes and
Commutator
Permanent Magnet Rotor
 Rotor losses are nearly zero
Stator is driven from an Inverter, which,
in turn, is powered from the AC line
 The “Electronic Inverter”
 “Commutates” the stator magnetic fields
 Synchronous machine
 Speed and torque controlled
 Interfaces to the HVAC controls
ECM-Driven Systems
How’s an ECM
Industrial Systems
Different
Than a PSC Motor?
The Rotor
 Stator current produces magnetic
field that acts on rotor:
 Permanent magnets on rotor
oppose stator field
 No current flows in rotor
 Rotor losses are very low
 Torque is controlled by adjusting
current in stator
 Resilient isolation from shaft
 Stator current produces magnetic
field that acts on rotor:
 Rotor “slips” in stator-produced
field, inducing currents in rotor
 Rotor currents create magnetic
field to oppose stator field
 Current in rotor causes I2R losses
and heat
 Limited torque control
ECM-Driven Systems
How’s an ECM
Industrial Systems
Different
Than a PSC Motor?
Operation and Application
 Controlled by low voltage inputs
 Controlled by AC line
 Permanently connected to AC
line
 Motor starts softly, ramps to
speed
 Wide airflow range between hi
and low taps
AC Power
Power
Conditioning
AC to DC
Conversion
Inverter
 Start-up by contact to AC line
 Abrupt turn-on stress, noise
 Motor speed taps are inefficient
and produce only minor speed
adjustment
ECM
Blower
Motor
AC Power
Relay
Contacts
PSC
Blower
Motor
HVAC System Control
INPUTS
24Vac
Fan On
Rev Valve
Compressor Call
Heat Call
Capacity Select
Delay selects
Trim/Adjust
Humidistat
Available Outputs
RPM
OverSpeed
UnderSpeed
CFM Demand
Motor
Control
Block Diagram - ECM Motor & Control
start/run
capacitor
HVAC System Control
INPUTS
24Vac
Compressor Calls
low/hi//off
Continuous fan
Heat Calls
low stage
hi stage
aux/emerg
Motor
Control
Block Diagram - PSC Motor & Control
ECM-Driven Systems
Industrial Systems
The ECM’s Benefits in HVAC
Constant Airflow
 In a series of tests the motor is “taught” the relationship between
speed, torque, airflow and external static pressure.
 “Airflow” is Programmed by the HVAC OEM and is specific and
unique to the motor and air mover combination
 Airflow is easily set up and trimmed at the installation
 Uses an “Interface/Tap Board” and jumper or dip-switch settings
 No other motor offers so many ways to control comfort and efficiency
 Be sensitive to your customer …. “tailor” the airflow for him/her in
his/her unique installation
Capitalize on the unmatched flexibility of ECM-driven air
movers ….. Offer “Tailored Comfort”.
ECM-Driven Systems
Industrial Systems
The ECM’s Benefits in HVAC
ECM
Airflow Control
 Constant airflow over wide
external pressure changes
 Greater customer comfort and
satisfaction
PSC
 External pressure change causes:
 airflow variation as filter loads
 reduced performance
 poor latent/sensible capacity control
PRESSURE
Set the airflow level
and go!
System airflow is starved
Overblowing the system
• poor moisture removal
• high power
consumption
ECM-Driven Systems
Industrial Systems
The ECM’s Benefits in HVAC
Efficiency
 PSC motor:
 ECM:
 At 0.15” ESP (DOE rating
point): 2x the efficiency of
the PSC
 At 0.5”ESP (typical applied
condition): 40% greater
than PSC
550
3 speed PSC
Induction Motor
500
450
Input Power (Watts)
 optimized only at rated
design conditions
 highest operating cost
under most applied
conditions.
400
350
Induction
motor needs
over 100 Watts
more power
than GE ECM
280 Watts
300
250
Cut speed in half, cut
power by a factor of 8.
200
150
100
35 Watts
Variable Speed
GE ECM
50
0
250 300
350 400 450 500
500 550 600 650 700
750 800 850 900
Motor Speed (RPM)
950 1000
1000 1050 1100 1150 1200
ECM-Driven Systems
Industrial Systems
The ECM’s Benefits in HVAC
Constant Airflow - How does the motor know what to do?
1200
E
Speed (RPM)
1000
D
High Static Pressure
C
800
B
600
Low Static Pressure
400
A
200
Constant Airflow Profile (800 cfm)
0
0
10
20
30
40
50
60
70
Normalized Motor Torque (%)
80
90
100
ECM-Driven Systems
Industrial Systems
How the GE ECM™
Makes Airflow Constant
Unlike a conventional induction motor, GE’s ECM
motor regulates itself by automatically changing
torque and speed to maintain a programmed level of
constant airflow over a wide range of external static
pressures. This is accomplished through several
steps.
First, the air-moving system is characterized in an
airflow chamber for its torque and static pressure
operating range. That characteristic is then
programmed into the motor. Then the motor's
control is programmed with a set of desired airflows
(e.g. 800 cfm). That constant airflow is defined by
the ECM's speed and torque, which is expressed in
the graph nearby as the orange line. Point A on the
orange line, for instance, represents an airflow of
800 CFM at the initial level of static pressure in the
system, here called Low Static Pressure (see the
green line).
As long as the pressure remains constant, the ECM
motor will continue to deliver 800 cfm to the
system. This is referred to as a stable operating
point which is defined as any point where the
system profiles intercept the ECM constant airflow
profile. Points A and E in this example are the only
stable points for constant airflow in the graph.
If static pressure changes (for example, a clogged
air filter, or different installation), then the blower
speed will increase to Point B (see High Static
Pressure Curve, blue line). This increase in speed
occurs when any blower––whether equipped with
an ECM or AC induction motor––encounters an
increase in static pressure. The reason is that the
clogged filter restricts airflow in the system
meaning there is less air for the blower to propel
through the system. (This is akin to a car's wheels
losing traction on ice and spinning freely).
The airflow at Point B, however, is lower than
required to remain on the desired Constant Airflow
Profile as expressed by the orange line. The motor
will not operate at Point B because its programming
does not allow this combination of torque and speed
for this particular system. As a result, the GE ECM
patented algorithm will increase torque and speed to
find a new stable operating point on the High Static
Pressure Curve. Increases in torque will continue
until the speed and torque converge with the next
stable operating point, which in this case is Point E
on High Static Pressure Curve. When operating a
point E, the blower is delivering higher torque,
higher speed, but the same airflow as in point A.
© 2000 General Electric Company
ECM-Driven Systems
Industrial Systems
The ECM’s Benefits in HVAC
The ECM’s Sound Advantage
 Air noise dominates at high
airflow, but ECM still has a
slight advantage
 At ~70% of rated airflow
ECM is ~6 times quieter
than at max airflow
• PSC motor at rated
- 58.4
• ECM motor at rated
airflow
• ECM (512rpm)
• ECM (600rpm)
(free discharge)
50
40
30
20
10
 Overall DBA:
airflow
60
Sound level (Db)
 ECM can get to lower
airflow than PSC
Tone levels of ECM & PSC motors
- 58.1
- 39.4
- 44.0
0
100Hz
125Hz
200Hz
250Hz
500Hz
800Hz 1000Hz 1250Hz 1600Hz 3150Hz 6300Hz
Frequency (1/3 octave avg.)
ECM@1106RPM
PSC @1050RPM
ECM@512
ECM@600
At low airflow, ECM has clear sound advantage over all
other motor technologies (>14db quieter at ~1/2 capacity)
ECM-Driven Systems
Industrial Systems
The ECM’s Advantages
For the Equipment Manufacturer
 Improved system performance
 Optimum performance and efficiency at design and rating conditions
 Customer-tailored airflow at part load
 Standardized motors and controls leverage volume and reduce
inventory
 Reduced engineering development time
 Programmability
 GE-supplied development system simplifies application
 GE application support
ECM-Driven Systems
Industrial Systems
The ECM’s Advantages
For the Contractor
 Flexibility
 Used with conventional 1-stage, 2-stage or variable capacity T‘stats
 Conventional 24VAC interfaces
 Field adaptable and serviceable
 Wide cfm selection …. PLUS trim
 Constant cfm simplifies installation
 Capable of delivering proper airflow into applications with higher
restriction
 Replaceable controls make ECM repairable for the same price as
replacing induction motors
 Satisfied Customers
 Perceptible, Saleable performance and comfort
 Tailor airflow to the customer’s preferences
 Improve latent/sensible control
ECM-Driven Systems
Industrial Systems
The ECM’s Advantages
For the Homeowner
 Lower operating cost
 Greatest applied efficiency of any system
 Low stage and continuous fan airflows cost pennies to operate
 Higher comfort
 Low sound level
Soft start-up
Virtually silent low stage in 2-stage systems
 Precise airflow gives better humidity/discharge temp control
 Better filtration
 Satisfaction in quality
 Perceptible performance and comfort
ECM-Driven Systems
Installation and Service
ECM Connections
 5-Pin power connection
 16-Pin control connection
 Connector housing and control
openings are “keyed” – properly
insert connectors
 Don’t let water run into connectors
or openings
 Be careful when probing connector
and motor pins
 Familiarity with ECM-to-system
interface aids troubleshooting
Industrial Systems
ECM-Driven Systems
Industrial Systems
Installation and Service
Power Connection TIPS
 ECMs connect directly to the line
 Do Not insert contactors/relays in
series with either AC line
 Control is powered continuously
 insures reliable start-up
 maximizes reliability
 Pins 1&2 are jumpered in harness
for Furnace (115V) operation
 Line voltage should NEVER be
applied to pins 1 or 2.
5
4
3
2
1
AC Line
AC Line
Gnd
Lines 1&2 will be connected
for 120Vac applications only
 Make sure power is OFF before
inserting or removing power
connector
 Verify and re-verify connector
orientation before applying power
 Plug is Polarized
 Do Not force plug into motor
ECM-Driven Systems
Industrial Systems
Installation and Service
Power Connection TIPS
5
4
3
2
1
 Furnaces/115Vac applications
require series inductance in AC line
 All 3/4 and 1hp applications will use
inductor, 1/2hp may not
 Reason:
AC line currents are nonsinusoidal
Inductor reduces peak line
current
Maintains circuit “ampacity”
 Inductor should always be in line
(HOT) side.
AC Line
AC Line
Gnd
Lines 1&2 will be connected
for 120Vac applications only
 True RMS meters should be used
to measure line current
 Some clamp-on ammeters may not
read line current accurately.
 Remember -- the ECM’s current
will be very low at off-load
conditions because of its high
efficiency.
ECM-Driven Systems
Industrial Systems
Installation and Service
Low Voltage Connections Through the 16-Pin Connector
for cooling mode
latent/sensible capacity control
ECM-Driven Systems
Industrial Systems
Installation and Service
Control Connection Tips
 24 VAC Inputs operate motor - like a
conventional system
 Functions G, Y, Y1, Y2, O, W will
activate from 24Vac (R)
• Jumper R to G to activate fan at
fan-only speed
• R to G to Y will activate fan to
cooling speed
G, Y, Y1, Y2 are on a threshold of 1/2 the
“R” voltage.
 Stats that “steal” power through Y or
other functions are NOT compatible
 Some solid state relays cannot turn
off G and Y.
 Don’t apply high voltage to control
pins
 Don’t apply 24Vac to Out+ or Out-
ECM-Driven Systems
Industrial Systems
Installation and Service
Control Connection Tips
 Make sure connector is fully seated
 Make sure pins from harness are
fully inserted into connector
 Make sure transformer common(C)
is tied to C1 and C2
 Pins 5, 11, 7, 4 access four Tables
programmed into the motor:
• Heat Airflow
• Cool Airflow
• Start/Stop ramps and delays
• Airflow Adjust or Trim
 Don’t apply high voltage to control
pins
 Don’t apply 24 Vac to Out+ or
Out-
ECM-Driven Systems
Installation and Service
Set Up TIPS
 Use the manufacturer’s service and
installation documents to set-up the
system
 Airflow VALUE (based on
system capacity) must be set by
switches
 Adjustments to the cooling
airflow are made
 All of the motor connections
should be understood
Industrial Systems
ECM-Driven Systems
Industrial Systems
Installation and Service
Equipment Manufacturers use a variety of interface and
set-up techniques:
Shunts/Jumpers
Dip Switches
Set-up must be done for ECM-driven systems to operate properly.
ECM-Driven Systems
Industrial Systems
Installation and Service
Set Up TIPS
 Changing:
 Heating airflow
 Cooling Off delay
 Cooling airflow
require the unit to be cycled
before the change takes effect
off
 Cooling Adjust or Trim changes
take effect immediately
ECM-Driven Systems
Industrial Systems
Installation and Service
Control Connection Tips
 Interface/tap boards select the system’s
airflow capacity and operating profiles.
 Heating airflow @ pin 11 of ECM
 Cooling airflow @ pin 5 of ECM
 Profiles/Off-delays @ pin 4 of ECM
 Airflow trim at pin 7 of ECM
These settings must be made for the system to operate properly.
ECM-Driven Systems
Installation and Service
Control Signal
Measurement Tips
 True RMS meters should be used
 Presence of half-wave signals from
interface board can be determined
Industrial Systems
ECM-Driven Systems
Industrial Systems
Installation and Service
What If…
 … “Y”, ”G”, ”W”, ”W2” are all off but the
ECM is still running? ... Now what??
 … the changeover valve signal (“O”) is not
connected in a conventional air handler, so why is
is it in an ECM-driven Air Handler?
 … “Y” is not connected in the blower’s low voltage control box.
What will the cooling CFM be?
 … the dip-switch settings on the interface card are not changed
at installation?
 … dip-switches controlling cooling and heating capacity are changed
but the CFM doesn’t change!
 … there is no 24Vac on pin 12 of the ECM’s 16 pin connector?
ECM-Driven Systems
Industrial Systems
Installation and Service
What If answers…
 … “Y”, ”G”, ”W”, ”W2” are all off but the
ECM is still running? ... Now what??
The system is probably being controlled by a thermostat that uses solid state
relays or triacs as output switches. The current leaking through such
switches can cause a voltage level to appear on the ECM Motor’s terminals
that make it react as if the thermostat is actually calling.
Another cause could be a high impedance compressor contactor or fan relay
coil that causes a voltage above one-half the control transformer output
voltage to appear on terminals “Y” or “G” of the motor.

… the changeover valve signal (“O”) is not
connected in a conventional air handler, so why is
is it in an ECM-driven Air Handler
Unlike induction motor-driven systems, ECM driven systems tailor airflow
in heating and cooling with separate airflows for each. The ECM needs to
know the mode in which the system is operating to select the proper airflow.
ECM-Driven Systems
Industrial Systems
Installation and Service
What If answers…

… “Y” is not connected in the blower’s low voltage control box.
What will the cooling CFM be?
If “Y” is not connected, the ECM-driven blower will only respond to the “G”
terminal in cooling. This means the blower will only operate at the “FANONLY” air volume and will not change to the “Cooling” airflow required
during compressor operation. The system will probably trip-off on high
compressor head pressure or, if there is sufficient airflow to prevent that, the
system’s capacity will be seriously degraded and will cause system reliability
degradation and comfort complaints.

… the dip-switch settings on the interface card are not changed at installation?
The dip switches on the interface card select airflow to match the size of the
system installed. If they are not verified to be in the position matching the
size of the condensing or heat pump unit, the indoor airflow will be grossly
over-blown or under-blown. Also, the DELAY and TRIM functions will
remain in factory default positions and may not be appropriate to the
customer’s home, preferences or lifestyle.
ECM-Driven Systems
Industrial Systems
Installation and Service
What If answers…
… dip-switches controlling cooling and heating capacity are changed but the CFM doesn’t change!
In all probability, the switches were changed while the ECM-driven blower
was running. The blower must go through an off-cycle for the new settings
to take effect.
… there is no 24Vac on pin 12 of the ECM’s 16 pin connector?
Without 24VAC from the low voltage transformer present at pin 12 of the
ECM, the motor will not respond correctly to most of the control functions;
specifically, “O”, “Y1”, “Y/Y2”. It is important that in all systems
depending on these inputs that “R” be connected to pin 12 of the ECM. The
“Analyzer” troubleshooting tool can pin-point that problem, if it exists.
ECM-Driven Systems
Industrial Systems
Installation and Service
Constant Airflow TIPS
Air Volume vs Ext SP
 ECM airflow programs are specific to
the motor, blower and cabinet
combination — DO NOT
• Don’t exchange between different
OEM products
• Don’t exchange between furnaces
and air handlers
Cu Ft/min
EXCHANGE ONE MOTOR
MODEL WITH ANOTHER
1-ph PSC Lo
1-ph PSC Med
1-ph PSC HI
1700
1600
1500
1400
1300
1200
1100
1000
900
0.0
0.2
0.4
0.6
0.8
Ext Static Pressure (" H2O)
 CFM - NOT SPEED - is commanded
by the controls -- G, W, Y, Bk, etc…
 Speed and torque change to hold CFM constant over a broad range
of external static pressure
1.0
ECM
ECM-Driven Systems
Industrial Systems
Installation and Service
Constant Airflow TIPS
 Low static, high quality ducted
applications will run slowly, quietly
and efficiently….. while delivering
the correct airflow.
 High static applications will run
fast, be noisy and power
hungry…. The ECM may still
provide the correct airflow, but at a
price!
ECM-Driven Systems
Industrial Systems
Installation and Service
Constant Airflow TIPS
 The ECM can help a distribution
problem, but BEWARE of
EXTREME CASES!
 Sometimes a problem can only be
fixed at its source!
• Talk to homeowner
about his ductwork
 The motor program limits torque
when a certain speed is reached
 High static pressure will activate
the torque limit
 The motor will slow and airflow
will fall off
 In extreme cases huffing may
occur
 Solution -- Reduce the restriction!!!
 Take out high pressure drop
filters
 Look for a problem in the #1
problem site in HVAC systems the air distribution system
ECM-Driven Systems
Industrial Systems
Installation and Service
TIPS on Isolating the problem
 Verify blower wheel is free and tight.
 Verify line voltage at control connector
-- both lines and ground.
 Use the HVAC SYSTEM and
ECM ANALYZER to isolate the
problem to the motor or controls.
ECM-Driven Systems
Industrial Systems
Installation and Service
TIPS on Replacing the Control Module
 If the motor doesn’t run ...
 Check out the motor per the procedure in the equipment
manufacturer’s literature
or GED7161
 If the motor’s good, replace the
Control only...
 It’s cheaper and it’s faster!
 Use the correct replacement module
 While you’re there, look for other evidence -- Any Water?
 If replacing an ECM2 control, use the Thru-Bolts and locater TAB that come with
the replacement control
 Make sure the control housing is centered and flush with the motor end-shield
 Don’t over tighten - snug will do!