Generic Service Preso

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Hows the GE ECM Motor different than an
Induction Motor? Operation
Construction The ECMs Electronics The
ECM's Benefits and Advantages in HVAC
Efficiency Constant Airflow Sound
Tailoring to the Customer Programmability Inst
allation 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
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• 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

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Hows an ECM 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

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Hows an ECM Different Than a PSC
Motor? Operation and Application

• Controlled by low voltage inputs
• Permanently connected to AC line
• Motor starts softly, ramps to speed
• Wide airflow range between hi and low taps

• Controlled by AC line
• Start-up by contact to AC line
• Abrupt turn-on stress, noise
• Motor speed taps are inefficient and produce only
  minor speed adjustment

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The ECMs 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.
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The ECMs Benefits in HVAC ECM Airflow
Control PSC

• Constant airflow over wide external pressure
  changes
• Greater customer comfort and satisfaction

• External pressure change causes
• airflow variation as filter loads
• reduced performance
• poor latent/sensible capacity control

Set the airflow level and go!
System airflow is starved
PRESSURE

• Overblowing the system
• poor moisture removal
• high power consumption

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The ECMs Benefits in HVAC Efficiency

• PSC motor
• optimized only at rated design conditions
• highest operating cost under most applied
  conditions.
• ECM
• At 0.15 ESP (DOE rating point) 2x the
  efficiency of the PSC
• At 0.5ESP (typical applied condition) 40
  greater than PSC

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The ECMs Benefits in HVAC Constant Airflow -
How does the motor know what to do?
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The ECMs Benefits in HVAC
The ECMs Sound Advantage

• Air noise dominates at high airflow, but ECM
  still has a slight advantage
• ECM can get to lower airflow than PSC
• At 70 of rated airflow ECM is 6 times quieter
  than at max airflow
• Overall DBA
• PSC motor at rated airflow - 58.4
• ECM motor at rated airflow - 58.1
• ECM (512rpm) - 39.4
• ECM (600rpm) - 44.0

At low airflow, ECM has clear sound advantage
over all other motor technologies (gt14db quieter
at 1/2 capacity)
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The ECMs 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

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The ECMs Advantages

• For the Contractor
• Flexibility
• Used with conventional 1-stage, 2-stage or
  variable capacity Tstats
• 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 customers preferences
• Improve latent/sensible control

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The ECMs 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

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Installation and Service
ECM Connections

• 5-Pin power connection
• 16-Pin control connection
• Connector housing and control openings are
  keyed properly insert connectors
• Dont let water run into connectors or openings
• Be careful when probing connector and motor pins
• Familiarity with ECM-to-system interface aids
  troubleshooting

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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 12 are jumpered in harness for Furnace
  (115V) operation
• Line voltage should NEVER be applied to pins 1 or
  2.

• 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

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Installation and Service
Power Connection TIPS

• 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 non-sinusoidal
• Inductor reduces peak line current
• Maintains circuit ampacity
• Inductor should always be in line (HOT) side.

• True RMS meters should be used to measure line
  current
• Some clamp-on ammeters may not read line current
  accurately.
• Remember -- the ECMs current will be very low at
  off-load conditions because of its high
  efficiency.

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Installation and Service
Low Voltage Connections Through the 16-Pin
Connector
for cooling mode latent/sensible capacity control
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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.

• Dont apply high voltage to control pins
• Dont apply 24Vac to Out or Out-

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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

• Dont apply high voltage to control pins
• Dont apply 24 Vac to Out or Out-

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Installation and Service
Set Up TIPS

• Use the manufacturers 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

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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.
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Installation and Service
Set Up TIPS

• Changing
• Heating airflow
• Cooling Off delay
• Cooling airflow
• require the unit to be cycled off before the
  change takes effect
• Cooling Adjust or Trim changes take effect
  immediately

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Installation and Service
Control Connection Tips

• Interface/tap boards select the systems airflow
  capacity and operating profiles.
• Heating airflow _at_ pin 11 of ECM
• Cooling airflow _at_ pin 5 of ECM
• Profiles/Off-delays _at_ pin 4 of ECM
• Airflow trim at pin 7 of ECM

These settings must be made for the system to
operate properly.
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Installation and Service
Control Signal Measurement Tips

• True RMS meters should be used
• Presence of half-wave signals from interface
  board can be determined

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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 blowers 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 doesnt change!
• there is no 24Vac on pin 12 of the ECMs 16 pin
  connector?

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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 Motors 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.

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Installation and Service
What If answers

• Y is not connected in the blowers 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
  FAN-ONLY 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 systems
  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 customers home, preferences or lifestyle.

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Installation and Service
What If answers

• dip-switches controlling cooling and heating
  capacity are changed but the CFM doesnt 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 ECMs 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.

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Installation and Service
Constant Airflow TIPS

• ECM airflow programs are specific to the motor,
  blower and cabinet combination DO NOT EXCHANGE
  ONE MOTOR MODEL WITH ANOTHER
• Dont exchange between different OEM products
• Dont exchange between furnaces and air handlers
• 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

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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!

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Installation and Service
Constant Airflow TIPS

• 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

• 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

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Installation and Service
TIPS on Isolating the problem

• Use the HVAC SYSTEM and ECM ANALYZER to isolate
  the problem to the motor or controls.

• Verify blower wheel is free and tight.
• Verify line voltage at control connector -- both
  lines and ground.

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Installation and Service
TIPS on Replacing the Control Module

• If the motor doesnt run ...
• Check out the motor per the procedure in the
  equipment manufacturers
  literature
• or GED7161
• If the motors good, replace the
• Control only...
• Its cheaper and its faster!
• Use the correct replacement module
• While youre 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
• Dont over tighten - snug will do!