For Fasco blower motor wiring, the brown wire indicates start. The yellow indicates power.
The black wire on this model indicates high speed. The rest of the taps are speed taps, but there is an option of having a single-speed application depending on your preference. If you prefer high speed and it gets too much for you to withstand, you can move the black wire to one of the other taps that are RED low speed or blue medium speed. All of the above is applicable but not limited to the old Fasco motors.
For the New motor:
The white wire goes to the yellow wire for the capacitors. The black goes to the black wire where the high speed is taken from in the old Fasco blower motor. The green is a neutralizer and it goes to the ground as the brown wire goes to the capacitor as shown in the diagram. If the capacitor fails to discharge, the capacitors need to be replaced.
It is recommended that every time you replace your Fasco blower motor with a new one, you replace the capacitor as well to avoid future inconveniences.
How to Read HVAC Wiring Diagrams
Step 1: Review the symbols
All companies have their terms of reference. Some companies may refer to an electronic part as a transformer and other companies will refer to the same thing as a starter. Depending on the model you will be working on, there will most definitely be a key or another symbol in place for you to identify. Make sure to check the manufacturer’s specific code in such a case.
Step 2: Follow the color codes
Most manufacturers use wires that are color-coded to make it easier for users to identify. The diagrams come with keys that show the specific symbols and terminologies. For instance, the key that is at the bottom of the diagram may indicate that the purple wire powers the inducer motor while the red wire goes directly to the thermostat.
Step 3: Let the flow of electricity guide you
Most of the time, the flow of electricity in wiring diagrams is indicated using arrows that are superimposed at the top of the wire. When the arrow points to one direction, it means that the electricity flows from a starting point on one side of the arrow to the ending point on the other end and the flow does not reverse at any point. This will enable you to pinpoint the exact point at which electricity stops flowing and this will enable you to determine the problem with your unit.
Step 4: Use an electrical multimeter
Some of the resistors in the wiring diagrams are shown to have 1 to 3 ohms of resistance within them. You will have to verify this information using your multimeter tool to ensure that the part is in spec.
How to Wire a Fasco 4-speed Blower Motor
A Fasco 4-speed motor blower is essentially a device that is found in most HVAC (heating, ventilation and air conditioning) units. These Fasco blower motors are fitted into electric heat furnaces and air conditioning units.
They provide multiple fan speeds with the help of multiple internal coils. This is why they contain many wires. The following are step by step instructions on how to wire the Fasco 4-speed blower motors:
- Shut off the main power supply to the HVAC unit that is located at the power panel. You have to use the manufactures wiring manual to verify the wiring configuration of the blower motor as well as the size of the control switch that should be used with the unit. Locate and identify the black and white wires that are used to supply power to the unit.
- The white wire should be connected to the common wire that is on the motor. Use plastic twist caps to secure this wire connection. Connect the black hot wire to the hot terminal that is at the speed controller of your unit’s Fasco blower motor. Some instructions usually come with the speed controller that is supposed to help you identify the speed terminals 1 through 4. Read through those carefully and make sure that you comprehend every instruction.
- To the speed wire of the terminal, connect the speed terminal 1 to it. Then connect the speed terminal 2 to the medium-low speed wire of the motor. For speed terminal 3, connect it to the medium high-speed wire. Lastly, for speed terminal 4, connect it to the high-speed wire of your unit’s Fasco blower motor. If there are any splices on the wire connections, cover those with plastic twist caps. For those blower motor models whose two high-speed wires are connected with a capacitor, connect only to one of the two high-speed wires.
- Turn the power to your HVAC unit back on. Turn the Fasco blower motor on and then take it through all four speeds.