BEMAC UGS-21 | Automatic Generator Control Device

Description

Product Overview

The BEMAC UGS-21 is an integrated automatic generator control device designed for marine electrical power systems. It coordinates generator operation by monitoring bus and generator electrical conditions, controlling standby generator selection, and managing the synchronization process before a generator is connected to a common bus. Once generators operate in parallel, the controller supports automatic load sharing to distribute electrical demand between operating generator sets. These functions are important on vessels where power demand changes with propulsion equipment, pumps, compressors, cargo machinery, and other onboard electrical loads.

The UGS-21 combines generator automation with power management functions. BEMAC documentation identifies automatic synchronizing, automatic load sharing, bus power monitoring, standby generator selection, and generator operating-count control as core functions. It also supports large-motor start blocking logic, which can prevent selected high-capacity auxiliary equipment from starting when available generation capacity is insufficient. The electrical input information published for this model identifies 110 VAC secondary voltage measurement, 5 A AC generator-current measurement, and an auxiliary supply range of 18–32 VDC. These measurement inputs are normally associated with suitable instrument transformers and current transformers; primary generator or bus voltages must not be connected directly unless the equipment documentation explicitly permits it.

For maintenance and procurement teams, the BEMAC UGS-21 is relevant to existing marine generator control installations where the original power management architecture must be maintained. Replacement work requires more than matching the model designation. Verify the voltage-transformer ratios, current-transformer ratios, generator ratings, breaker control wiring, governor and AVR interfaces, synchronization settings, and load-sharing configuration. BEMAC also describes newer distributed generator automation products, including BE-P20, but these represent different system architectures rather than automatic substitutes for the UGS-21.

Product Introduction (Non-Templated)

When multiple generators feed a common shipboard bus, synchronization and load distribution directly affect power continuity. The UGS-21 combines generator monitoring, automatic synchronizing, load sharing, and generator-count management in an integrated control device.

Before replacing an installed unit, record the CT and PT ratios, breaker interface wiring, governor and AVR connections, and operating parameters. Incorrect measurement scaling or control settings can cause synchronization failures or unequal generator loading.

Key Technical Specifications

The 110 VAC, 5 A, and 18–32 VDC ratings are supported by equipment identification records. Exact I/O counts, output ratings, communication options, and environmental limits should be confirmed from the unit’s nameplate and BEMAC documentation.

UGS-21

Related Products

The following are related BEMAC generator automation components and systems. They are not confirmed direct replacements for the .

• BE-P20 – Distributed generator automatic control system with automatic synchronization, load sharing, bus monitoring, and power management.
• BG-GCS – Generator control system component used in BEMAC’s distributed generator automation architecture.
• BG-PLC – Programmable control component associated with BEMAC generator automation systems.
• BG-GW – Gateway component used in the BE-P20 system architecture.
• UST-201-D – BEMAC interface circuit board reference.
• UST-205-D-1308E – BEMAC control-system PCB reference.
• UST-206-D – BEMAC interface/control PCB family reference.

The BE-P20 and BG-series references belong to BEMAC’s broader generator automation portfolio. Confirm the system architecture and interface requirements before considering a migration or component substitution.

Frequently Asked Questions

Q1: What is the BEMAC used for?

The is an automatic generator control device used in marine power systems. It monitors generator and bus conditions, controls automatic synchronization, supports load sharing, and manages the number of generators operating according to electrical demand.

Q2: Does the support automatic synchronization?

Yes. Automatic synchronization is one of its documented core functions. The controller monitors electrical conditions and coordinates generator connection to the bus. Correct PT ratios, phase sequence, breaker timing, and generator control interfaces remain essential.

Q3: Can the manage generators of different capacities?

Its automatic load-sharing function is intended to distribute generator load. However, the precise load-sharing behavior for generators with different rated capacities depends on the configured system, governor interfaces, and generator parameters. Confirm the original engineering settings before changing generator combinations.

Q4: Can I hot-swap the while the generator system is operating?

Do not assume live replacement is permitted. The is involved in generator synchronization and power management. Follow the vessel’s approved electrical maintenance procedure, establish a safe operating configuration, and ensure that generator breaker control cannot be affected unexpectedly.

Q5: Can I use the with a 440 VAC generator bus?

The documented measurement input is 110 VAC secondary. A suitable voltage transformer may be required to scale the primary bus voltage to the controller’s specified input. Never connect a 440 VAC bus directly to a 110 VAC measurement input.

Q6: Does the support firmware v3.1?

A firmware version cannot be confirmed from the model designation alone. Check the installed controller revision, software documentation, and original system configuration. Do not assume that software for a newer BEMAC generator automation system is compatible with the .

Q7: What should I verify before purchasing a replacement ?

Check the nameplate, hardware revision, auxiliary supply, voltage and current input ratings, terminal arrangement, and physical dimensions. Also compare the CT/PT ratios, breaker wiring, governor and AVR interfaces, and saved control settings. For used equipment, request functional test documentation covering synchronization and load-sharing operations.

Procurement note: The is a generator automation controller, not a generic PLC I/O module. Its measurement scaling and breaker-control interfaces are critical to safe operation. Confirm the complete installed configuration before approving a replacement, particularly the 110 VAC voltage measurement and 5 A current measurement circuits.