How to Check if an Automatic Door Motor is Bad

Automatic doors are a convenient and efficient way to allow people to move in and out of a building. However, over time, the motor that powers the automatic door can start to wear down and eventually fail. If your automatic door is not functioning properly, the motor may be the culprit. Here's how to check if your DC motor is bad:

Step 1: Disconnect the Power

The first step to checking if your automatic door motor is bad is to disconnect the power. This is essential for safety reasons and to avoid any potential damage to the motor or voltmeter. Make sure the power to the motor is turned off and that the door is in the closed position before proceeding.

Step 2: Identify the Motor

Once the power is disconnected, identify the motor. Look for any visible damage to the motor housing, encoder, or motor wires.

Step 3: Check for Power

The first test to perform is to check for power to the motor. Using a voltmeter, set it to DC voltage and touch the positive probe to the positive terminal on the motor and the negative probe to the negative terminal on the motor. If the voltmeter reads a voltage, then the motor is receiving power and the problem may lie elsewhere.

Step 4: Check for Short To Ground

Next, set the voltmeter to ohms or resistance. Check for ground by touching the negative probe of the voltmeter to the motor's metal frame. Touch the positive probe of the voltmeter to the positive terminal of the motor. If the voltmeter reads 0 ohms, then the motor is a direct short. If there is any continuity at all the motor is bad. If there is infinite ohms present, then that indicates the motor is okay. Repeat this test for the negative terminal of the motor.

Step 5: Check for Resistance

The final test to perform is to check for resistance in the motor. This will help determine if the motor is bad and needs to be replaced. To perform this test, touch the positive probe of the voltmeter to the positive terminal on the motor and the negative probe to the negative terminal on the motor. The voltmeter should read a resistance value in ohms. Refer to the following ohm ranges below for your specific automatic door. If the resistance is outside of this range, then the motor is bad and needs to be replaced.



Besam Swing Doors
Swingmaster 300: 13 ohms
MP: 1.5-2.2 ohms
SW100: 1.5-5 ohms
SW200i: 1.5-5 ohms
Swingmaster 900: 1.8 ohms

Besam Sliding Doors
Power-Glide A Series: 15 ohms
Power Glide B Series: 11 ohms
Power-Glide 4000 C Series: 1.5-2.2 ohms
Power-Glide D Series (CUD9 Control Type): 4.9-5.7 ohms
Unislide: 1.5-5.5 ohms
SL500: 2.5-5 ohms

Dorma Swing Doors
ED700 (Old Style Control Type): 65-88 ohms
ED700 (Green or Yellow Control Type): 16-30 ohms
ED400 (White or Blue Control Type): 16-30 ohms
Dorma ED800: 1.5 ohms

Dorma Sliding Doors
ESA 1: 2.5-6.5 ohms
ESA 2: 1.2-5.3 ohms

Doromatic Swing Doors
Astroswing: 30 ohms
Benchmark: 3.5-10 ohms
Junior Swing: 54-60 ohms

Doromatic Sliding Doors
Astroslide 1: 13.3-16.5 ohms
Astroslide 2: 13.3-16.5 ohms
96K: 1.2-5 ohms

Horton Swing Doors
EasyAccess 7100 Series (4160 or 4190 Control Type): 15-21 ohms
EasyAccess 7100 Series (7160-3 Control Type): 28 ohms
HD-Swing 4100 Series (4160 or 4190 Control Type): 15-21 ohms

Horton Sliding Doors
Horton 2000 Linear Drive (2160-2 Control Type): 15-21 ohms
Horton 2000 Linear Drive (2150-1 and Up Control Type): 15-21 ohms
Horton 2003 ProSlide (2150-2 and Up Control Type): 15-21 ohms
Horton 2001 HD-Slide (2150-2 and Up Control Type): 15-21 ohms

Horton Sliding Windows
Horton 8100 (8160-3 Control Type): 27 ohms

Keane Monroe Swing Doors
3000 (K Control Type): 14.3-17.2 ohms
3500: 15 ohms
3800 (L Control Type): 16.9-18.1 ohms

Nabco Gyro Tech Swing Doors
GT 400: 26 ohms
GT 300/400/500 (Gemeni Control Type): 29 ohms

Nabco Gyro Tech Sliding Doors
GT 1100: 20.2-21.8 ohms
GT 1175 (All U Controls Except U30): 18.4-26 ohms

Stanley Swing Doors
Stanley Magic Access: 28 ohms
Stanley Magic Force (MP Control type): 10-16 ohms
Stanley Magic Force (521 Control type): 10-16 ohms
Stanley Magic Swing (MP Control type): 10-16 ohms
Stanley Magic Swing (521 Control type): 10-16 ohms

Stanley Sliding Doors
Stanley Dura-Glide (Model J Control Type): 10-16 ohms
Stanley Dura-Glide (521 Control Type): 10-16 ohms

Tormax Swing Doors
1101 / 1202 (TDS Control Type): 2 ohms
1101 / 1202 (Smart Drive Control Type): 2 ohms

Tormax Sliding Doors
9000 Series (TCP51LC Control Type): 2 ohms
9000 Series (TCP51 Control Type): 2 ohms

Conclusion

Checking if an automatic door motor is bad is a straightforward process that can be done using a voltmeter. By performing tests for power, short to ground, and resistance, you can determine if the motor is the issue and needs to be replaced. Keep in mind that if you are not comfortable performing these tests, it is best to seek the assistance of a professional to avoid any potential damage or injury. At Automatic Door and Hardware, we are your leading source for automatic door repair and replacement parts. If you are in need of a new DC motor for your automatic door, we offer a wide range of options to suit your needs. Contact us today to learn more about our products and services!

Automatic doors and automatic door replacement parts are available at www.autodoorandhardware.com.