Basler Electric DECS-150 Digital Excitation Control System

A potted, low-cost digital excitation controller for rotary excited generators

The Basler Electric DECS-150 is a high-powered, low-cost and environmentally rugged controller for the output of rotary excited synchronous generators. Basler positions it for machines that run in parallel with other generators or with the utility, and names distributed generation, cogeneration and peak shaving as ideal uses.

Compared with the larger DECS-250 it trades field current for size and price: the PWM stage is rated 10 Adc continuous at 55 C, the case is a potted 1.79 kg unit, and the design tolerates up to 40 percent total harmonic distortion from six-thyristor loads while holding 0.5 percent accuracy.

DECS-150 control functions and protection

• Voltage regulation accuracy 0.25 percent; 0.5 percent up to 40 percent THD
• 63 Vdc and 125 Vdc PWM output at 10 Adc; 7 A PWM stage gives high field forcing
• Var/PF control, voltage matching and manual mode (field current regulation)
• Overexcitation, underexcitation and stator current limiting; exciter diode monitor (EDM)
• Loss of sensing and transfer to manual; external autotracking over CAN
• Load sharing over Ethernet; Modbus TCP; auto-tuning with two PID stability groups
• Rugged potted design; IP54 rating when the rear-mounted USB option is selected

DECS-150 technical specifications

Power and output

Inputs, outputs and communication

Environment and mechanical

DECS-150 or a larger controller?

The deciding figure is field current. If the exciter field of your alternator needs more than 10 Adc continuous, or you need integrated generator protection such as 27/59, 81O/U or 32R, step up to the DECS-250 listed in the datasheet. Confirm the field resistance against the table above: 9 ohm minimum on the 63 Vdc output and 18 ohm on the 125 Vdc output. The style chart in the datasheet sets USB location and power input, so quote us the complete style code of the unit being replaced.

Installation and commissioning notes

Setup is by PC through the BESTCOMSPlus software, which is included, with customisable BESTlogicPlus logic. Power can be taken from a shunt connection or a PMG running between 50 and 500 Hz. For redundancy, the CAN port supports external autotracking to a second unit. If the DECS-150 replaces an older regulator, check sensing voltage ranges and CT secondaries (1 A or 5 A) before energising.

Typical DECS-150 applications

The potted construction targets harsh sites: engine-driven sets in remote oil and gas camps, cogeneration units and peak-shaving sets exposed to heat and vibration. The datasheet lists a salt fog test to IEC 60068-2-11, which is relevant to coastal Gulf installations, though the product is still intended for panel or terminal-box mounting rather than direct outdoor exposure.

Selection and care notes

The DECS-150 must be matched to the generator field data, so collect the exciter field voltage and current, the rated generator voltage and frequency and the sensing transformer ratios before ordering. Commissioning with the free configuration software lets the settings be saved and compared later, and the limiters and protection functions should be set from the machine data sheet. Wiring of the field output and the sensing inputs must follow the diagrams in the manual.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the machine or system it will control and any accessories or software needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification before a purchase is confirmed. Ratings, functions and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related Basler Electric items

Basler lists the ICRM-7 and ICRM-15 inrush current relays for PWM regulators powered from an independent source, the MVC manual voltage controller, the DECS-250, the DGC-2020, DGC-2020ES and DGC-2020HD genset controllers, BE1-FLEX and ES Series protection relays.

Frequently asked questions

What field current can the DECS-150 deliver?

10 Adc continuous at or below 55 C and 7 A at 70 C, on 63 Vdc or 125 Vdc PWM outputs.

How accurate is the voltage regulation?

0.25 percent, and 0.5 percent with up to 40 percent total harmonic distortion from six-thyristor loads.

Does it support paralleling?

Yes. It offers load sharing over Ethernet, var/PF control and a 1 A or 5 A paralleling CT input.

Can I use a PMG as power source?

Yes. The power input accepts a 50/60 Hz shunt connection or a PMG operating at 50 to 500 Hz.

Is Seven Star LLC a Basler Electric distributor?

No. Seven Star LLC is an independent supplier in Muscat, Oman, sourcing genuine Basler Electric products for GCC customers on request.

Documents and quotation

Download the DECS-150 product bulletin (SZT-13, 01-24) from this page and read it alongside the manual when you verify the model code. Our quotation form takes the exact model, options and quantity, and Seven Star LLC, an independent Muscat supplier serving the GCC, replies with availability for Basler Electric equipment. No prices are listed; confirm all ratings, options and approvals against current manufacturer documents before ordering. Related pages: Diesel Generator Spare Parts, Basler Electric.