What makes marine testing different
A ship's electrical plant is an isolated grid with no utility behind it, so paralleling, load sharing and load-acceptance capability all have to be verified item by item before delivery. Class surveys normally require main generators to run continuously at rated power and 0.8 lagging power factor, with voltage and frequency checks on load acceptance and rejection.
The emergency generator additionally has to demonstrate auto-start time, automatic changeover and sustained running at the specified load. These tests are run alongside at the quay, which calls for transportable load equipment with stepped control.
The role of an R+L load bank
Marine load banks are usually resistive plus inductive, because motor loads dominate on board and the plant power factor sits around 0.8. Only with reactive load applied does the excitation system and AVR operate at its design point, and only then are voltage regulation and transient recovery measurements meaningful.
Environment and construction
Salt-fog corrosion, hull vibration and limited installation space add requirements: corrosion-protected enclosures and resistor elements, vibration-resistant terminations, and airflow arrangements that suit deck or engine-room exhaust conditions. LANDI marine R+L load banks are built to these conditions and can be dimensioned to the yard's own drawings and interfaces.