An automatic transfer switch is essential in an emergency power supply system. When a power failure is detected, the automatic transfer system activates the standby power source and acts as a bridge between equipment and power supplies. These devices prevent power surges that can damage appliances and ensure that power is safely transferred from the primary supply to the backup generator.
When the regular power source is restored, these steps are reversed by the device. If this device is not working properly because of improper electrical panel installation, it is recommended to avail of a repair from Roosevelt Electrical Services. Regardless, this article shows why your automatic transfer switch is not working properly:
- Tripped circuit breaker
As mentioned, power surges within the building can trip the circuit breaker that powers the automatic transfer switch. Unfortunately, the automatic transfer switch cannot operate the emergency supply power system if there is no power supply. This is the most common problem for your ATS and should always be one of the first things to look into during a breakdown.
- Faulty electrical wires
A two-wire system typically powers automatic transfer switch controllers. When the cables are damaged, incorrectly installed, or too old, they cannot connect properly. A faulty connection may also cause irreversible and severe damage to the switch, generator, and emergency energy system. Routine maintenance and checks will aid in identifying any damaged or broken wires, allowing for replacement before the unit is required.
- Defective controller
When an outage occurs, a defective automatic transfer switch controller may send wrong signals to the generators. The system may fail to initiate a power switch or may initiate a change when one is not required. If there is a suspected failure, not all controllers must be replaced. Your controller unit may be repairable and reprogrammable, so call a trusted electrician to do regular testing for your controller.
- Transient voltage
A transient voltage is defined as a voltage spike, dip, or fluctuation that occurs with the charge. Safeguards may be installed to suppress these rapid shifts, but these issues are relatively common. These voltage flows can cause damage to the automatic transfer switch’s sensitive parts, resulting in lesser efficiency. Damage to the control board can cause further defects to the rest of the unit as the charge flows into the automatic transfer switch. Ensure that the transient voltage surge protector is operational in your unit at all times or during routine checks.
- Failed transfers
An open disconnected breaker can result in failed transfers between the automatic transfer switch and the generator. Unregulated voltage levels can also cause this issue in your electrical system. These problems can be resolved by resetting the service disconnect breaker. If there is a storm in your area, waiting for the storm to pass by or waiting for the voltage to return to an acceptable level is advisable. However, if one of these situations arises, a skilled technician is still recommended to inspect the unit as soon as possible.
How Do You Fix An Automatic Transfer Switch?
Not everyone experiences the same issue with their automatic transfer switch. However, that does not mean one should ignore when the automatic transfer switch is not performing correctly. It is still recommended to troubleshoot the automatic transfer switch to ensure that the building has power in times of emergency.
Although it may be complicated to figure out the right fix for your ATS issue, there are step-by-step guidelines to follow depending on the issue you’re experiencing with your automatic transfer switch. You may want to read this article to know how to troubleshoot your automatic transfer switch issues without professional help.
1. The generator does not start during a power outage
- It is as simple as removing the two wires coming from the generator’s controller and shorting the two wires together to troubleshoot this type of problem. This event will start and run the generator. If the generator fails to start and run, the issue is with the generator. If the generator fires up, the issue is with the automatic transfer switch.
2. The generator won’t stop running even if the power is back on
- If the generator will not stop running, the first step is to check the automatic transfer switch to see if it recognizes purchased power as acceptable. See the control panel of your automatic transfer switch.
- Check the phase-to-phase voltage if the utility power is not recognized as acceptable. It must be within 5% plus or minus of the nominal value. In the United States, nominal voltages are 208 volts, 240 volts, and 480 volts. The automatic transfer switch has a control board failure if the utility voltage is within 5% of the nominal value. Lightning strikes cause these transient surges. Wait for the storm to pass if this is the issue.
- Remove the two wires that connect the generator controller to the automatic transfer switch if it recognizes and supplies purchased power to the load as indicated on the control panel. If the generator stops, the automatic transfer switch controller is faulty; if it does not stop, the problem is with the generator.
3. The automatic transfer switch will not transfer to generator power
- Look at the control panel of the automatic transfer switch to see if the generator’s power is acceptable.
- Check the phase-to-phase voltage at the Automatic Transfer Switch TS unit’s emergency lugs if the automatic transfer switch does not recognize the generator’s power as acceptable. This voltage must be within 5% of its maximum and minimum values. If this is satisfactory, check the frequency with a digital voltmeter rather than the one on the generator. If the generator’s frequency is not plus or minus 3.0 hertz, the automatic transfer switch will not recognize the generator power as acceptable and will not switch the load to it.
Do you still need help figuring out the solution to your defective automatic transfer switch? You may consult our professional electricians at Roosevelt Electrical Services or learn more about your ATS issue by reading our other articles.