In Tech Support

Step-by-Step Instructions for Installing Fan Motors

At MTA, we believe that every motor matters, and we’re committed to providing you with the resources you need to make the most of your motors. While there are numerous factors that impact the performance of the replacement fan motors in your broiler houses, there are several best practices you can follow to ensure you install each motor correctly and maximize the life of your motors.

Below is a list of step-by-step instructions we recommend you follow whenever installing belt drive fan motors in broiler houses, egg production facilities, dairy farms or other agricultural settings.

1. Make sure the drive pulley is aligned with the axle pulley. After mounting the motor, use a straight-edge or ruler to ensure the drive and axle pulleys are aligned. This 48-inch Aluminum Ruler from Harbor Freight works great and only costs $5.

2. Double-check the size of the drive pulley and axle pulley. It’s important to make sure you’re using the correct sized pulleys with your belt drive fan motor. A good rule of thumb is that, for every 10% you increase the diameter of the pulley, you increase the power needed to drive the fan by 33%. This adds unnecessary wear and tear to the motor and can lead to premature failure. Use this handy Pulley Size Data Sheet to check the exact pulley you need for your particular exhaust fan.

3. Set the belt tension correctly. If your belt tension is set correctly, you should be able to twist the belt with your thumb and forefinger a ½ turn – and feel resistance. Also, check the belt for visible cracks. If you see cracks inside the belt, it’s time to replace it.

4. Inspect the fan itself. Turn the prop of the fan with your hand to ensure it turns smoothly. This quick test is a good indicator to ensure the bearings of your exhaust fan are in good working order. You should also clean the fan props of feather and litter dust to help eliminate turbulence and restricted openings. Studies estimate that you can experience an up to 40% loss in air flow with the first 1/8-inch of accumulated dust and dirt on fans.

5. Measure the motor current and voltage. This last step is the most important – and perhaps the one that’s most often overlooked. Simply put, the only way to know if your replacement fan motor is setup correctly is by measuring the current and voltage. This is your opportunity to prevent problems – before they occur.

To take this measurement, we recommend that you use some sort of clamp-on amp meter similar to this one, which can be purchased through Amazon. This particular amp meter is relatively inexpensive, and we have used it with success. You won’t be disappointed, and it’s well worth the purchase. Once you have an amp meter, set it on the 20A range to measure current. When you measure the voltage, set it on the V range.

If the motor has been installed correctly, the running amps should be the same or below the amps listed on the nameplate. In the example of our 1.5hp fan motor, the rated amps is 5.89.

1.5hp fan motor label

Make Amp Readings Easier Than Ever.

If you want to make things easier for future fan motor installations, you might consider creating a 2-foot test cord. To do so, use a male plug at one end and a female plug on the other end. Use only the type of flat cord as you see in the image, where you can see the three conductors clearly. If you take a sharp knife and slit the cable to separate the hot wire from the ground wire – long enough to allow you to clamp your amp meter jaws around the separated wire, then you’ll be able to read the current without needing to measure it at the motor connection box. It’s simple, and it’s safe!

cord for installing fan motorsThe cable you would need is a 14/3 SPT-3, black, 105°C,15A, 300v, thermoplastic flat cable. The plugs are NEMA 6-15,15A-250v. The male plug is 5666-X and the female plug is 5669-X. You can expect to spend $20 for both of them.

Have Questions? We’re Always Here To Help.

If you experience multiple fan motor failures, there’s a very good chance that there’s an underlying electrical issue that could be causing it. Whatever the case, we’re here to help minimize headaches and maximize the life of your fan motors.

If you have questions, call 864-402-4682 or contact us today.