Datakom DKG-309 Automatic Mains Failure Unit

A proven AMF unit for single or dual mutual-standby gensets

The DKG-309 is a comprehensive automatic mains failure (AMF) unit for single-genset standby or dual-genset mutual standby operation. It comes in two versions: MPU, which uses a magnetic pickup for speed, and CANBUS, which connects to ECU-controlled electronic engines over J1939 so that engine control, protection and instrumentation need no extra senders and ECU warnings are displayed in text. The DKG-309 is a straightforward panel-mount unit with plug-in connectors, and every program parameter can be changed from the front pushbuttons without an external programming unit. It is listed with other items from our diesel generator spare parts category.

Technical specifications

Conformity entries on the datasheet: EN 61010 (safety) and EN 61326 (EMC) as CE reference standards, and UL/CSA certificate 20110527-E314374 referencing UL 508 Edition 17, UL 2200 1st Edition, UL 840 Edition 3 and CSA C22.2 No. 14 Edition 10.

Operating modes, alarms and telemetry

The user manual describes five modes. STOP energises the mains contactor if the mains phase voltages are within limits and keeps the engine stopped. AUTO is the genset and mains automatic transfer mode: when any mains phase leaves its limits the mains contactor drops, the engine starts after the preheat timer, runs unloaded for the heating period and then closes the generator contactor once voltage and frequency are in limits. On mains return the engine keeps running for the mains waiting period, load goes back to mains, and the unit applies the cooldown before stopping the fuel solenoid. RUN keeps the set running in an emergency backup mode, and TEST transfers the load to the genset indefinitely.

Faults are divided into three priority levels: alarms (immediate genset contactor release and engine stop), load dumps (contactor release and stop after cooldown) and warnings. The manual lists protections for low oil pressure, high temperature, low fuel, low coolant level, rectifier fail, emergency stop, low and high speed, start fail, stop fail, overload, excess power, low and high genset voltage, battery voltage, charge failure, mains phase-order fail and ECU fail. The last 100 events are logged with time stamps and 18 measured parameters, and the RS-232 port supports Rainbow remote monitoring, MODBUS, and GSM or PSTN modems with SMS sending on fault.

Selection and installation notes

Order the MPU version for mechanical-governor engines that provide a magnetic pickup, and the CANBUS version for J1939 electronic engines; state the engine make and model when you request a quote. The unit accepts selectable oil-pressure sender types such as VDO 0-7 and 0-10 bar and DATCON ranges, and a programmable table for non-standard senders. Mount the unit in a 151 x 111 mm cut-out, connect a fused DC supply of 9-33 V-DC, and make sure the battery negative is grounded as shown in the typical connection drawing. Mutual standby needs two units and the I/O expansion port can add relay expansion modules (up to 22 relays, 16 volt-free, with two modules).

Other programmable features listed in the datasheet include a built-in daily, weekly and monthly exerciser, weekly operation schedule programs, multiple language support, a customer logo display capability, event logging with time stamp and measurements, and I/O expansion. The battery-backed real time clock keeps the schedule and the event times correct after a supply loss, and the plug-in connection system allows a replacement unit to be fitted without rewiring.

Selection and installation notes

A generator controller is selected from the start and transfer logic needed, the number of sets, the engine and alternator signals and the communication required. Check the battery supply range, wire the voltage and current inputs and the engine sensors as the manual shows, set the engine and protection parameters from the engine and alternator data and test the start, stop, transfer and every protection with the set running before handover. Keep a copy of the parameter file with the site documents.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories 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 and the site risk assessment before a purchase is confirmed. Ratings, standards 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.

Documents and quotation

Both the datasheet and the user manual (63 pages, version dated 23.08.2013) from Datakom are provided for download. Contact us with the engine model and version needed for a quotation.