What should the first response be for a System Operator facing heavy loading and low voltage?

The first response for a System Operator facing heavy loading and low voltage should be to put capacitors in service. This action helps support the system voltage by providing reactive power, which is especially crucial during periods of heavy loading when voltage levels tend to drop. By adding capacitors, the operator can alleviate the low voltage condition and stabilize the system, allowing it to operate more efficiently.

Capacitors increase the overall reactive power flow in the system, counteracting the effects of loading, which can cause voltage to sag. Maintaining voltage levels is essential for the reliable operation of electrical systems, as low voltage can lead to equipment malfunctions and increased risk of outages.

In contrast, taking lines out of service can further exacerbate the low voltage problem by reducing the capacity available to meet demand. Putting reactors in service can also be detrimental in this scenario because reactors absorb reactive power, and may worsen the voltage conditions rather than improve them. Lowering loads could be an operational response, but it is not always feasible or the most efficient way to respond to heavy loading and low voltage situations. Thus, putting capacitors in service stands out as the most effective initial action.