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