An automatic transfer switch plays a fundamental role in the emergency supply power system. These devices facilitate a safe transfer of power from the primary or mains supply, to the backup generator. After sensing a power failure, the automatic transfer system invokes the standby power source and serves as an intermediary between equipment and power supplies. These steps are then reversed upon the return of the regular power source. Before changing between sources, the switch will verify that the supply is within the desired parameters and is stable.

While these devices ensure the safety and reliability of a backup power supply, some issues can prevent the device from working correctly. From our extensive experience, these are the most common problems that can present in an automatic transfer switch.

Tripped Circuit Breakers

Power surges within the facility can trip the circuit breaker that provides power to the automatic transfer switch. Without a supply of power, the automatic transfer switch is unable to operate or trigger the emergency supply power system. This malfunction is the most common problem and should always be one of the first considerations during a breakdown.

Transient Voltage

Transient voltage is a spike, dip or fluctuation of voltage that occurs along with the intended charge. While measures are installed to shield, filter or suppress these rapid shifts, these issues are still relatively common. Voltage transients may be triggered by a sudden release of energy previously-stored or induced by a heavy inductive load or lightning. These voltage flows can damage the sensitive components in the automatic transfer switch, causing malfunctions or lapses in functionality. As the charge flows into the automatic transfer switch, damage to the control board can also trigger further damage to the rest of the unit. The simplest way to protect your transfer switch from these hazards is to ensure the proper functioning of the transient voltage surge protector.

Damaged Wires

Automatic transfer switch controllers typically use a two-wire start system. When a power outage is identified, the relay that is held open by utility power closes. This closure forces the two wires together and causes the generator to start. When the cables are damaged, incorrectly connected or too aged, they are unable to connect correctly. Wires that are partially connected may provide an interrupted power supply, with frequent lapses in connection. Such a poor connection may also cause irreversible and severe damage to the switch, generator and entire emergency energy system. Routine maintenance and checks will help identify any damaged or broken wires, allowing for a replacement before the unit is required. This proactive approach will ensure your back-up supply is reliable and fully-functioning.

Bad Controller

A damaged automatic transfer switch controller may send inappropriate or unwarranted signals to the generators when an outage occurs. The system may fail to trigger a power shift or may trigger a change when it is not needed. Not all controllers require a replacement if there is a suspected failure. Many units may be repaired and reprogrammed. Regular testing and maintenance of your automatic transfer system will highlight any potential issues within the controller and ensure the appropriate repairs can be arranged before the unit is required for use.

Damaged Solenoids

A solenoid valve can be damaged by unfavourable pressure differences, manual overrides, damaged armature tube, residual coil power, missing components and damaged valve seats. Improper voltage over extended periods can also cause irreversible damage to the solenoid valve. When the plug is damaged, solenoids can cycle too fast and cause intense heat to build up. This overactivity can cause burns outs and failure in the automatic transfer switch, generator and entire emergency power supply system. Damaged solenoids can also fail after damage during maintenance or through the build-up of dirt and grime within the generators. The simplest way to avoid such problems is to maintain regular testing and servicing of the devices. By routinely cleaning out the contraption, you can prevent the accumulation of any foreign bodies or solid materials. This process will ensure the potential issues are recognised and rectified before the event of a power outage.

Failure to Transfer

Failed transfers between the automatic transfer switch and the generator can result from an open disconnected breaker or incorrect levels of voltage. These issues may be rectified by resetting the service disconnect breaker or waiting until the voltage returns to an acceptable level. If these situations do arise, it is essential that a skilled technician assesses the unit as soon as possible. This will help prevent any ongoing damage and reduce the likelihood of future disruptions and breakdowns.