Catalogue
Controller CDU-12 for Chemical Dosing Unit

Purpose and field of application

The CDU-12 controller is designed to operate as part of the chemical dosing unit used for controlled injection of chemicals into the annulus of oil wells, and into the oil gathering pipeline.

THE CONTROLLER PERFORMS THE FOLLOWING FUNCTIONS:

• control of the plunger pump drive for chemicals dosing in the manual and automatic mode;
• chemicals flow rate control;
• cyclic operation of the chemical dosing unit at the required flow rate;
• automatic restart of the unit in case of power supply failure;
• light indication of the unit operation modes: “STOP”, “STANDBY”, “IN OPERATION”;
• tank level control, including calculation of the volume and weight of the chemical;
• chemical’s temperature control in the tank;
• chemical’s heating control in the tank;
• control of pressure in the discharge line (contact pressure gauge or pressure sensor);
• electrohydraulic pusher motor protection (motor current and power voltage control);
• discharge line temperature control;
• control of discharge line heating;
• control of the production well switchboard status;
• control of the chemical dosing unit operation from the production well switchboard;
• indication of unauthorized access to the chemical dosing unit;
• reporting the unit status to the dispatch system;
• chemicals flow rate control via RS-485 interface;
• unit operation control via RS-485 interface;
• transmission of current parameters and the event log to the telemetry control system via RS-485 interface;
• event logging (65536 records with adjustable period);
• copying the event log to a standard USB stick via the USBHost interface;
• recording the number of plunger pump strokes;
• recording daily and total chemicals consumption since the start of the system operation;
• recording the operating time of the unit.

CONTROLLER’S SPECIFICATIONS

PARAMETER		VALUE
Rated supply voltage, V		10 (50 Hz), 25 (50 Hz)
Maximum voltage deviation from average , %		-50... +50
Power consumption, W, max		40
Ranges of controlled parameter variations and measurement errors relative to the upper range limit:
current, A		0... 5 (±1.0%)
voltage, V		0... 380 (±1.0%)
chemical temperature, °C line temperature,°C		-50... +150 (±1.0%)
Ranges of analogue input variations and measurement errors relative to the upper range limit:
chemical level, mA line pressure, mA		4... 20 (±1.0%)
Discrete inputs		8
Relay outputs		7
Switching capacity
4 outputs	Voltage, V, max	250
	Current, A, max	6
3 outputs	Voltage, V, max	125
	Current, A, max	3
Interfaces		RS-232, RS-485 (2 pcs.), USB-Host
Weight, kg, max		2.0
Overall dimensions, mm, max		210x230x78
Climatic version		UXL2
Enclosure type		IP43, NEMA3, NEMA4