The M-5329 LTC Backup Control provides the extra protection that can save your customers from the hazards and inconvenience of excessively high or low voltage on any phase. Defective LTC tapchanger controls can cause either too high or too low a voltage along the line, possibly damaging customers’ motors, computers or televisions. Even when the control is operating properly, customers close to the transformer may receive dangerously high voltage as the line drop compensator attempts to maintain a constant voltage under heavy load at a central point on the distribution line. The Beckwith Electric M-5329 LTC Backup Control can be installed as a solution to both of these problems.

The M-5329 will prevent a defective LTC tapchanger control from running the voltage outside the upper and lower voltage limits and, in addition, will prevent the line drop compensator from raising the voltage too high under full load or overload conditions. Setting the voltage bands on the M-5329 slightly wider than the transformer control limits will assure that a failed control will not result in a runaway LTC transformer. Under full or overload conditions, the M-5329 automatically takes over as an upper voltage limit control, not affected by load current, to prevent damage to equipment close to the transformer. While the Block Raise contact prevents a raise operation, a Lower contact forces the tapchanger down if the primary voltage should subsequently rise.

• Provides all components that must be added to an LTC Transformer for paralleling, using the circulating current method
• Prevents a defective LTC tapchanger control from running the voltage outside the upper or lower limits
• Prevents the line drop compensator from raising the voltage too high under full or overload conditions
• Monitors all three-phases and blocks LTC tapchanger operation if any phase is outside the setpoints
• Fully transient protected and operates within ±1% voltage accuracy over a temperature range of -40° to +80° C