The line voltage 115 vac power supply to the motor is constant and not switched by the control board. Sep 08, 2008 well, we have been selling air handlers with these in them for quite some time now, but in my 10 years in the trade, i have never had to fix or troubleshoot onr until now. The controller then sequentially energizes the three motor phases at the appropriate time for optimum operation. Uses up to 15% fewer watts than standard psc motors.
It last 8 years before a fused trace on the control module and two drivers burnt. Do not operate the motor without blower wheel attached. This motor has all of the capabilities of previous ecm blower motors but it does not have to be preprogrammed at the factory. So, yes, the blower motor issue needs to be resolved first. The biggest disadvantage of this motor is its complication. Confirm the motor is applicable to the hvac system using the application guide above. Motor blower speed three blower speed outputs are provided. However it is recommended that the whole blower assembly, with the motor, be removed from the furnaceair handler. Troubleshooting the capacitor gas furnace short cycling the ecm motor. Ecm programmable, allowing for advanced characteristics that are impossible to create using conventional motor technologies. The ecm motor tester is designed to isolate the ecm blower motor and run it at several speeds to help the technician determine if the blower motor is defective. The control controls a multiple speed ecm motor through the 6pin p3 connector. Singlephase 120 or 208240 ac power is supplied to the motor module, which converts that voltage to three phase dc voltage.
Ge offers a few basic checks that technicians should perform before troubleshooting the ecm motor. No matter how urgent the problem and motor failure can cause some very urgent problems always develop a plan of attack before you start repair work. Hvac ecm variable speed blower motor troubleshooting. The difference between variable speed and x motors. Electronically commutated motor ecm shown in figure 5 is different than previous generations of variable speed blower motors. Such operation will cause the motor speed to oscillate up and down. Knowing how to troubleshoot and diagnose problems with. Found 2nd x motor on the same unit bad within a years time today an noticed the molex plug thats on the ignition board flipped backwards. Powered by ecm technology constant airflow variable speed communicated ecm genteq models 2. Disconnect power unit before removing or replacing connectors, or servicing motor. Kg7t c and l series features and benefits two stage. Repeat component test by turning setup switch sw16 off and then back on. Set meter to ohms, and place meter leads in any two 2 wires of the motor connector.
Turn off power to furnace and wait 5 minutes before continuing. Voltage symbols vary among different multimeters and may be displayed as. Both x and variable speed motors are dc or alternating dc if you prefer, 3 phase, permanent magnet rotor motors that use back emf to determine motor torque and adjust to load conditions. Tested old motor windings just for the hell of it before i installed the new motor. Blowers in older furnaces generally employ singlespeed permanent split capacitor psc motors while many newer furnaces use variablespeed electronically commutated motors ecms. Put 24 volts to pins 12 and 15 and 24 volt common to pins 1 and 3 at the motor fig. Ge ecm troubleshooter 4 button wthree position g switch all manufacturers 1. If a 120 vac cable is used with jumper and 277 vac is applied to the motor it will be destroyed. Whats the difference between a psc and ecm motors, and.
Motor operation is also dependent on a 24 vdc signal on one of the four speed taps on the motor. Kg7t c and l series features and benefits two stage, fixed. Both of these motors will have a high voltage harness as well. Dont automatically assume the ecm motor has failed. The motor is not prone to overheating and less maintenance will be required over periods of time because the motor uses a soft stop and start. Figure 1 typical motor efficiency f or a 50w motor shaded pole single phase the motor is a th capacitor three phase ecm an ecm is made up of two components. Troubleshooting the ecm motor can be very simple if you just remember that it not just on or off. Please refer to table 1 model matrix for a list of models that can be tested with this device. The difference between variable speed and x motors hvac. Ecm is the initials for electronically commutated motor.
Knowing how to troubleshoot and diagnose problems with these motors is an essential skill an hvac technician must possess. It is usually not necessary to remove the motor from the blower assembly. Part number part description part link 10b67 lennox 10b67 ecm 5. This manual will show you how to setup, program and troubleshoot. Warning you must have the correct replacement module and or motor from the hvac unit manufacturer that is a. I show you where the test voltage goes and how to check. Can someone tell me how to go about troubleshooting these things. Ever since, its ability to simplify training on the genteq ecm constant airflow variable speed and constant torque oem indoor blower motors has created an overwhelming demand. These integrated motor drives are used in the air moving as well as the residential and commercial hvac industries, providing unmatched performance. Its the trigger that circulates conditioned air throughout the home. This motor will operate clockwise cw or counter clockwise ccw rotation automatically with its builtin rotation sensing feature. Sep 14, 2012 as far as the leak, he needs a functioning motor to properly charge the unit. Motorpro training ecm troubleshooting nidec motor corporation. This connector provides connection for ecm speed common pin 1, speed output pin 2, blower enable pin 4, cool enable pin 5 and r output pin 6.
Oil burner control the control provides dedicated contacts to operate the tt input of an oil primary control. When the delay time has elapsed, the blower is ramped toward zero. A true ecm has a separate motor and a separate module and can be replaced independently of each other. Reinstall the blowermotor assembly into the hvac equipment. It can adjust the air flow depending on what the system is getting for feedback. Icp 9mace series troubleshooting manual pdf download. Furthermore, if this doesnt work then and you still have problems check with the manufacturer for an ecm blower motor troubleshooting flow chart or guide. Second, by adjusting the speed to match the exact cfm, the motor is very energy efficient.
Warning do not operate motor without blower wheel or fan blade attached. Commonly called variablespeed motors, these communicated ecms were and still are predominantly programmed with a constantairflow operating program. Dec 07, 2015 blower motor breakdown can be the result of anything from old age to failed bearings, high amp draw, electrical failure in the windings, dirt accumulation, and more. Gather up any background material you may have on hand and then use your senses to inspect the site. Check continuity of harness between tap select interface board tsib and motor.
I want an energy efficient blower fan motor, and have seen in other threads these referred to as ecm. Indoor blower motors o variable speed ecm o constant torque ecm. The blower motor plays an extremely important role in forcedair systems. Ecm standard speed controller all ecm speed controllers are manufactured by price. Motor phases are sequentially energized by the electronic. Development of the constantairflow ecm the first application of ecm technology in hvac was the oem indoor blower motor. Our book in this hvac ecm blower motor video, i go over the genteq x wiring connections, what. The electronics in the end bell energize the windings one after the other. While this motor is more complicated than a standard ac fan motor there are many benefits. These integrated motordrives are used in the air moving as well as the residential and commercial hvac industries, providing unmatched performance. Diagnosing and solving blower motor problems 20151207. Wait at least 5 minutes after disconnecting power before opening motor. If a motor has a 120 vac power cable with a jumper and 240277 vac is supplied to the motor it will be destroyed. Without the blower wheel, the motor will run continuously to a maximum speed and then stop.
Measure phase to phase resistance between all three 3 windings. When its necessary to disconnect the power from the hvac system, its always a good practice to verify that voltage has been disconnected, by using a voltmeter. If the motor does not run, replace the motor module. The ecm motor gray furnaceman furnace troubleshoot and. Ecm motor troubleshooting manual 3 ecm motor trobsootin ecm motor power cable 240277 vac black hot wire 240277 vac white neutral wire green earth ground wire note. On and off blower delay time switch settings motor blower speed three blower speed outputs are provided.
Variable speed ecm blower motors high efficiency 1. Check resistance between motor windings l1l2, l1l3 and l2l3. I used this 12hp ecm to replace the old blower motor that came with my furnace. Its way too loud when operating and i can really hear the air coming through the vents. Are all the variable speed blower fan motors ecm, or do i need to specify that. This motor has all of the capabilities of the previous ecm blower motor but has internal memory storage which provides operational information to the manufacturer. A true ecm has a separate motor and a separate module and can be replaced independently of each. Do not operate motor without blower wheel attached. They will adjust their rpm in an attempt to deliver the cfm that is. If an application requires high efficiency, variable speed, and low noise, a genteq. Jun 27, 2016 i show you where to measure for low and high voltage, what changes from one manufacturer to another, a common problem with the ecm motor communicating with the control board in the furnace or air. Does blower wheel spin with a slight ratcheting feel. Confirm the motor being replaced is a direct drive indoor blower motor operating at 115 or 230vac.
Of course, the increasing popularity of the ecm motor has led to a number of questions from technicians on how to service and troubleshoot ecm driven systems. If the motor does not run, unplug the 16 pin wiring harness from the motor fig. Ecm motor shaft turns, but not smoothly if the shaft with blower wheel disconnected is difficult to turn with the motor control attached. The brand name for this motor is the think tank which covers models ecm 2. Both are more efficient than the typical psc motor with ecm motors commonly being about 80% efficient and psc being about 60%. How do i determine if it is the board, the module, or. The genteq brand has earned a reputation as an industry leader of ecm and axial flux motors for over 30 years. The electronics used in these motors result in failures that are far more common than in the psc motor. Ecm motor troubleshooting part 1 york central tech talk. The motor itself has 3 identical windings, somewhat like 3 phase. An ecm increases comfort levels because rooms stay consistently coolwarm. Of course, the biggest advantage of the ecm motor is its energy efficiency. Whats the difference between a psc and ecm motors, and why.
Feb 05, 2018 in this hvacr video we go over the troubleshooting of the ecm 3. I show you where to measure for low and high voltage, what changes from one manufacturer to another, a common problem with the ecm motor communicating with the control board in the furnace or air. Need help troubleshooting ecm motor hvac pro forums. As far as the leak, he needs a functioning motor to properly charge the unit. In this hvacr video we go over the troubleshooting of the ecm 3. A standard psc blower motor increases speed as sp increases while amperage drops. Select the correct symbol and set the multimeter to the voltage closest to. Additionally, some manufacturers have a diagnostic tool that will confirm specific problems. Troubleshooting ge ecm driven systems desco energy. The ecm motor gray furnaceman furnace troubleshoot and repair. General electric variable speed troubleshooting manual. I called our supplier and we both figured the motor control was bad. Introduction to the high efficiency genteq ecm kryo fortress motor.
Ecm motor troubleshooting part 2 york central tech talk. Seems the ecm would try to speed up to increaee sp in a blocked duct. Instead the variable speed furnace control programs the ecm blower motor upon application of power to the ecm blower motor via the serial communication link between the variable speed furnace control and the ecm blower. Symptom causeprocedure motor rocks slightly when starting this is normal startup for ecm motor won. Make sure you go through the diagnostic steps completely before replacing the motor. First of all there are two components to an ecm motor the control module and the motor itself. This includes air conditioners, heat pumps, and furnaces. Singlephase 120 or 208240 ac power is supplied to the motor module, which. Mar 17, 2019 both are more efficient than the typical psc motor with ecm motors commonly being about 80% efficient and psc being about 60%. Gives up to 1 seer point efficiency gain in cooling. The motor control is what sets the ecm apart from any other motor. This connector provides connection for ecm speed common pin 1, speed output pin 2, blower enable pin 4. The ge ecm motor, currently used by most residential hvac systems is a brushless dc, three phase motor with a permanent magnet rotor. Two wiring harnesses connect the motor to the integrated control board and furnace power supply.