View
6
Download
0
Category
Preview:
Citation preview
EEM MOTORS
Two wiring harnesses connect the motor to the integrated
control board and furnace power supply.
The line voltage (115 VAC) power supply to the motor is
constant and not switched by the control board.
Motor operation is also dependent on a 24 VDC signal on
one of the four speed taps on the motor.
The airflow tables for heating and cooling speeds show the
relationship between airflow (CFM) and external static
pressure for each size furnace.
NIDAC EEM Motor
NIDAC VS Motor
Motor
Controls
4 Wire Motor & Control Sections
3 Bolts
Features
• Fully Enclosed Electronics
• 3 Phase Brushless DC
(single phase AC input)
• Ball Bearing Construction
• Integral Control Module
• Constant Torque Motor
Control Inputs
• C – Common
• T1
• T2
• T3
• T4
• T5 - Open
Medium
High
Multi-Speed Blower Wiring & Power Requirements
• The GMEC96 multi-speed blower Power requirements: 120VAC
Communication Wires
Power Wires
Low Cool (T1) Blue
High Heat (T2) Red
Low Heat (T3) Orange
Cool (T4) Black
120 VAC Black
Neutral White
Ground Green
DC Ground Red
Troubleshoot Multi-Speed Blowers- GMEC96
• Review wiring diagram to find that “L” is the black wire, and “N” is the neutral. (always white)
• Power on meter should be 115- 120VAC.
• If no voltage in plug, check power coming from ICM. (board)
Check 1 (cont)
• Check the line voltage
(120 Volts) to the motor (L to N).
• Check the input voltage
(24 DC Volts) to the motor
(C to T1, T2, T3, or T4).
• The motor either operates or it
does not.
Replacement
• One piece replacement motor.
• Make sure the belly band is
between the vents.
• Ensure proper drip loop in wires
to motor.
C L G N
1 2 3 4 5
High Voltage
Connections
3/16"
Low Voltage Connections
1/4”
Troubleshoot Multi-Speed Blowers- GMEC96
• Next, set thermostat to any mode of operation. (cool, heat, or fan only)
• Check voltage between position “C” of the power cord, and respective signal wire.
• We are using the high heat mode/ wire in this example.
• The high heat mode will be powered by the red wire connected to the T2 on the ICM.
Check 1 (cont.)
Troubleshoot Multi-Speed Blowers- GMEC96
• Set thermostat to call for “high heat.” (about 10 degrees above the current setting)
• Review the wiring diagram and the locations of the signal wires from blower as the connect to the ICM. (control board)
• The “high heat” connection is the red wire connected to T2 on the ICM.
• So, once furnace calls for high heat, a reading of 18-30VAC between position “C” of the power plug, and T2
Check 1: Signal Wire Example (cont.)
Mounted in housing ~ ¼” of shaft sticking out
Troubleshoot Multi-Speed Blowers (GMEC96)
• The GMEC96 multi-speed blower can be broken down into two sections for troubleshooting purposes:
115VAC Motor 1 Phase, ½ HP, 1200/VAR RPM
“End Bell” Contains capacitors and a NTC
thermistor to be inspected
Troubleshoot Multi-Speed Blowers- GMEC96
• Detach/ separate motor and end bell as directed earlier.
• Remove the motor connector from end bell outlet.
• Set meter to ohms, and place meter leads in any two (2) wires of the motor connector.
• Measure phase to phase resistance between all three (3) windings. (yellow, red, blue)
• Resistance between windings should be equal and less than 10 ohms.
Check 2: Troubleshooting Motor
Troubleshoot Multi-Speed Blowers- GMEC96
• Inspect components in the end bell, and ensure that they are not swollen or bulging.
• Remove the motor connector from the end bell outlet.
• Set meter to ohms, and place meter leads into any two (2) pins in the end bell outlet.
• A functioning control unit (end bell) should have a phase to phase resistance of greater than 100K between any two pins.
Check 3: Troubleshooting the End Bell
Mounting The EEM Motor
2.75” Bellyband
Keep Out Area
When using a bellyband for mounting, the band should not be
located in the area identified in the drawing below.
Recommended
Bellyband Area
Recommended