New DEC 3500 Controller from Kohler

Kohler’s newly designed Decision-Maker 3500 (DEC 3500) controller is equipped with paralleling and load-management software – allowing for automatic paralleling of two generators without the cost and extra footprint of switchgear.

“While load requirements have increased due to advanced electronics equipment, onboard space is still at a premium,” said Frank Formas of Kohler Power Systems. “Our new paralleling controller matches power capacity with load needs to eliminate under-loading and over-fueling, while conserving space, decreasing fuel costs and reducing equipment maintenance.”

The DEC 3500 offers a newly designed customer interface for easier data entry and retrieval. Advanced features include bus sensing, first on logic and synchronization. It can be operated in one of three paralleling modes: P-gen (Kohler-patented), droop, or V-bias/S-bias. In P-gen mode, just one communication wire enables paralleling, making repowering easier. With droop or V-bias/S-bias, the controller can parallel with existing load-share modules, which provides shipbuilders with multiple design options. Built-in load management software automatically monitors power needs, dropping the second generator when power is light and bringing it automatically online when load increases. This eliminates under-loading and over-fueling, the root cause of fuel-on-the-water issues. The controller also offers remote monitoring from anywhere on the vessel and features potted circuit boards and sealed connectors to protect against water and environmental corrosion.

Bus Sensing: One of the Dec 3500’s paralleling functions. The Dec 3500 controller’s software senses the load on the bus and makes split-second decisions regarding starting or stopping the second generator based on the load and on preset-set parameters.

First on logic. Another one of the Dec 3500’s paralleling functions. The Dec 3500 is capable of analyzing the condition of the PGEN-connected generators and decide which is able to start up and bring on line first.

The difference between paralleling types:
-PGEN: PGEN paralleling utilizes the embedded load share software within the Dec 3500 to manage the paralleling of the two generators.
-V-bias/S-bias: This type for paralleling uses Voltage Bias and Speed Bias inputs from an existing load share module in existing switchgear to manage this paralleling. Some repower applications require the use of existing switchgear. The Dec 3500 is flexible enough to parallel with existing switchgear if the need arises.
-Droop: paralleling supports “legacy” systems. Droop is uncommon today, but Dec 3500 supports droop paralleling as well as the others.

Kohler said it is the first to market with a entire line of Tier III-certified Marine generators in this power category.