Offshore Rig

Whether it's drilling for oil, moving freight containers, or simply spending time with family on a cruise, life continues at sea. Electric drives and motors are used everywhere from the cranes loading and unloading cargo to the propulsion systems that drive vessels. Below are several examples of common drive applications where Bonitron DC Bus Management solutions can be utilized.


  • Barges
  • Cruise Ships
  • Drilling Rigs
  • Ferries
  • Fishing/Factory
  • Military
  • Shipyards
  • Supply ships
  • Tankers


  • Cargo Ramps
  • Centrifuges
  • Conveyors
  • Cranes
  • Deck Lids
  • Drilling Rigs
  • Fans/HVAC
  • Propulsion
  • Pumps
  • Winches
Ship Equipment Locations

Dozens of cranes and winches are used throughout various marine applications. Typical winch motors are from 15 HP to 75 HP. Some have multiple motor and drives on one bus. DC voltage rises when a load is lowered (Drive holding back to prevent free fall). The rising in voltage can cause drive faults or require a drive to slow process to compensate

Bonitron Overvoltage Solutions are the ideal add-on to prevent overvoltage faults and control crane/winch braking.

For more information on AC accessories for crane applications, visit Cranes & Winches.

Motoring vs Overhauling Crane

Centrifuges are common in the marine industry, as they seperate solids and liquids or remove undesireable liquids from useful liquids. Examples include processing wastewater or separating water from fuel or hydrolic fluid.

Some problems with centrifuges are the long times required to coast to a stop. Braking the centrifuge generates excess power, which can cause a drive overvoltage fault.

Bonitron Overvoltage Solutions are the ideal add-on to prevent overvoltage faults and shorten centrifuge stopping time.


Whether your onshore or offshore, Drawworks and Top Drive/Rotary Table drilling rigs drill holes into the earth in order to extract petroleum. Most of these rigs utilize variable speed drives to control the raising and lowering of the travelling block (done via drawworks), as well as the spinning of the drill bit (done via top drive or rotary table).

Time is money in the oil industry. The faster the drawworks lowers the drill string back into the borehole after adding an extension, the better. The drill string is dropped and then stopped rapidly before hitting the bottom. This rapid deceleration requires drive overvoltage protection, commonly in the form of a Braking Transistor and Resistor.

A Top Drive or Rotary Table spins the drill string. Drill strings can be thousands of feet in length, so it is common for one end of the string to be spinning faster or slower than the other end (just as if you were to spin on end of a shoe string). Overvoltage protection on the top drive or rotary table is necessary in these cases to control torque on the drill string.

M3452 Braking Transistor

Braking Transistor

  • M3452 or M3575T
  • Up to 1600A per unit (Master/Slave Capable)
  • Local and remote status monitoring
  • System can be reconfigured on-the-fly
M3775R Braking Resistor

Resistive Load Banks

  • M3775R
  • Ratings up to MegaWatts
  • Galvanized steel enclosure
  • NEMA-3R and stainless steel options
Top Drive

Diesel-electric propulsion is used on tugboats, offshore/platform vessels, and workboats for dynamic position. Electric motors and drives have a faster response time, allowing for quick changes in direction. The quick stops and changes in direction cause voltage spikes that can cause drive trips.

Bonitron Overvoltage Solutions prevent overvoltage faults and shorten centrifuge stopping time.

Systems with multiple motor and drives will also benefit from the Bonitron Common Bus Solutions. These modules simplify the install by reducing the components and wiring needed to complete the system.

Ship Mechanical Schematic
Ship Cooling

Ships house many types of pumps, including mud pumps and process cooling pumps.

Smaller pumps can utilize Bonitron Uninterruptible Power for Drives to eliminate nuisance drive trips which can be frequent on ship power grids.

Marine Pump
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