DEIF GPU-3 Gas Generator Protection Unit

Protection for gas-engine generator sets

The DEIF GPU-3 Gas is the gas-engine version of the Generator Protection Unit. It is a compact microprocessor-based unit with all the galvanically separated 3-phase measuring circuits needed to protect a synchronous or asynchronous generator, and the data sheet describes it as intended for land-based applications. It fits PLC-controlled plants, interfacing through binary and analogue I/O or serial communication. Where the marine GPU-3 is class approved, DEIF states only that the GPU-3 Gas is UL/cUL listed.

Technical specifications

Engine control and synchronisation

With the engine control and protection option the unit controls the start and stop sequence and can serve as a backup engine protection unit with its own power supply and processor, so engine shutdown channels still work if the main processor fails. On gas sets the engine interface card provides a combined run coil or gas valve output. Synchronisation is an option; once the breaker closes the regulation is switched off and the unit carries out protection only.

The display is separate and can be installed on the main unit or in the switchboard door with the 3 m display cable included; up to two extra displays can be added within 200 m. A cyclic self-test at start-up reports faults in clear text and on a status relay. M-Logic, the micro-PLC tool in the free PC utility software, assigns functions to inputs and outputs.

Options and ordering

The data sheet lists options A (mains protection), C (add-on generator protection), D1, E and F analogue outputs, G2 synchronisation, H serial and engine communication, L display gasket, M engine control or I/O extension, N Ethernet, Q1 class 0.5 accuracy and Y display layouts. Accessories include display cables of 1, 3 and 6 m, AOP-1 (2912411070) and AOP-2 (2912411060) operator panels, and an additional display (2912890030). The worked example is 2912120220-01 GPU-3 Gas 01 with M4, Y1 and H2.

How the DEIF GPU-3 Gas works

The GPU-3 Gas measures the three-phase voltage and current of a generator through galvanically separated inputs. It compares the readings with the protection set points, such as over-current, reverse power, over-voltage and frequency limits. When a value passes its limit for the set time, the unit trips the breaker or raises an alarm through its relay outputs. With the engine control option it also runs the start and stop sequence of a gas engine, with a run coil or gas valve output on the engine interface card.

Where the DEIF GPU-3 Gas is used

• Gas-engine generator sets
• Land-based power plants
• PLC-controlled plants
• Synchronous and asynchronous generators
• Backup engine protection

Selection checklist for the DEIF GPU-3 Gas

• Measuring voltage of 100 to 690 V AC
• Current input of 1 or 5 A
• Auxiliary supply of 12 or 24 V DC
• Engine interface card and options
• Relay and analogue outputs
• Display on the unit or in the panel door
• Synchronisation option
• UL/cUL listing needs

Installation, commissioning and maintenance notes for the GPU-3 Gas

Mount the base unit in the panel, which is rated IP20, and fit the display where the operator can see it. Wire the current transformers with care, because open secondary circuits are dangerous. Connect the 12 or 24 V DC supply and the relay outputs. Enter the set points from the plant study and test each protection before the set is released for service.

Requesting a quotation for the DEIF GPU-3 Gas

Please send the generator data, the voltage and current ratings, the options and the quantity. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

GPU-3 Gas measuring ranges

The voltage range is 100 to 690 V AC with a tolerance of plus or minus 20 percent. The frequency range is 30 to 70 Hz. The current input withstands 20 times In for 10 s.

GPU-3 Gas outputs

Relay outputs are rated 5 A at 250 V AC or 30 V DC. Analogue outputs are 0(4) to 20 mA and plus or minus 25 mA.

GPU-3 Gas environment

The operating temperature is minus 25 to 70 degrees C. The display is IP40, or IP54 with a gasket. The base unit weighs 1.6 kg.

GPU-3 Gas listing

The data sheet cites UL/cUL listing to UL508 and recognition to UL2200. The document is 4921240399I, 16 pages.

Protection records for the GPU-3 Gas

Keep the set point list, the test dates and the software version in the plant file.

Choosing the right GPU-3 Gas setup

Choose the options from the engine type, the interface needs and whether the unit will synchronise.

Documents and quotation

The attached file is the DEIF GPU-3 Gas data sheet 4921240399I (EN). Send the model and variant or option letters, the quantity, the engine make and ECU protocol and the project standard for a quotation. See Diesel Generator Spare Parts for related DEIF controllers and generator control products.