Introduction
For manufacturers operating automated production lines, CNC machining centers, conveyors, and heavy-duty industrial machinery, reliable lubrication is essential to maintaining equipment performance and minimizing unplanned downtime. However, manually managing multiple lubrication points becomes increasingly difficult as equipment complexity, operating hours, and production speeds increase.
A PLC control centralized lubrication system provides a more coordinated approach. By connecting the lubrication pump to the machine's programmable logic controller (PLC), lubrication cycles can be synchronized with equipment operation, while pressure, lubricant level, and circulation signals can be monitored to identify potential problems.
At
BAOTN, we provide centralized lubrication solutions covering both grease and oil lubrication. This article explains how to design a PLC-controlled lubrication system for industrial applications and how to select the appropriate pump according to lubricant type, pipeline configuration, lubrication demand, and control requirements.
Before selecting a lubrication pump, engineers should evaluate the number of lubrication points, required lubricant volume, pipeline layout, working pressure, and control signal requirements. These factors determine whether a volumetric oil lubrication system or a progressive grease lubrication system is more suitable.
This guide also introduces practical BAOTN pump options and explains how to integrate lubrication equipment with an existing PLC control system.
When Does an Industrial Machine Need PLC-Controlled Centralized Lubrication?
PLC-controlled lubrication is particularly valuable when a machine has multiple lubrication points, operates continuously, or needs to coordinate lubrication with its production cycle.
Typical applications include:
CNC machining centers: Guide rails, ball screws, and bearings require scheduled lubrication to maintain positioning accuracy and reduce friction.
Automated production lines: Multiple mechanical units operate simultaneously, making centralized lubrication more practical than individual manual maintenance.
Industrial conveyors: Bearings, transmission components, and other moving parts need consistent lubrication during extended operating periods.
Heavy-duty machinery: High mechanical loads and demanding operating conditions require reliable lubricant delivery and effective pressure monitoring.
For example, in a CNC machining center, the PLC can trigger the lubrication pump according to preset intervals or machine operating conditions. The pump then supplies lubricant to guide rails, ball screws, and other designated lubrication points through the distribution network.
This coordinated control helps ensure that lubrication is performed according to the machine's operating schedule. Optional level or pressure monitoring signals can also be connected to the machine control system to alert operators when abnormal conditions occur.
In these applications, the PLC can initiate lubrication according to preset time intervals or machine operating conditions. It can also receive feedback signals from the lubrication system, helping operators identify low lubricant levels, abnormal pressure, or incomplete lubrication cycles.
The result is a lubrication process that works as part of the overall machine automation system rather than as an independent maintenance task.
How to Design a PLC Control Centralized Lubrication System
A practical system design should begin with the lubrication requirements of the equipment, not simply the selection of a pump.
Step 1: Identify Lubrication Points and Lubricant Requirements
First, identify all components requiring lubrication, including bearings, guide rails, sliding surfaces, and transmission mechanisms.
Determine the required lubricant type, quantity, frequency, and operating conditions for each point.
For applications using lubricating oil, a volumetric oil lubrication system can deliver measured quantities through compatible distributors. For applications requiring grease, a progressive lubrication system can distribute grease through progressive distributors to multiple lubrication points.
Oil and grease systems should not be treated as interchangeable. Their delivery characteristics, distributor configurations, and operating pressure requirements must match the actual application.
The distribution method should also be considered during system design. A volumetric oil lubrication system uses metering distributors to deliver a predetermined quantity of oil to each lubrication point. A progressive grease lubrication system uses progressive distributors to deliver grease sequentially through connected outlet sections.
The distributor type must match the lubrication pump and the required lubricant characteristics. Selecting an incompatible distributor may result in insufficient lubricant delivery or unstable system operation.
Step 2: Select the Appropriate Pump and Distribution Structure
The pump must provide sufficient delivery capacity and working pressure for the entire lubrication network.
BTA-C2: Designed for small and medium-sized machinery, supporting up to 50 lubrication points and a main oil pipeline length of approximately 25 meters. It is suitable for CNC machines and machining equipment.
BTB-C2: Equipped with an induction motor, this model is designed for machinery requiring longer main oil pipelines and larger oil supply volumes.
BTD-C2: Also equipped with an induction motor, BTD-C2 provides another option for industrial equipment with extended pipeline layouts and higher oil supply requirements.
The final selection should be based on the required oil delivery volume, pipeline resistance, distributor configuration, and working pressure.
GEN-1: An electric progressive grease pump suitable for centralized lubrication systems in machine tools, CNC equipment, conveyors, plastics, and textile machinery. Its lubrication cycle can be controlled by the host PLC or an independent controller.
GEO-1: Designed for CNC lathes and machine tools, providing progressive grease delivery with PLC or independent controller operation. Its grease cartridge configuration also makes lubricant replacement more convenient.
GET: A high-pressure progressive lubrication pump designed for industrial applications requiring flexible lubricant delivery and pressure configurations. It supports N68 or higher-viscosity lubricating oil and NLGI 000–2 grease, depending on the selected configuration. Available displacement options include 2.0, 2.8, and 4.0 mL/min, with nominal pressure options of 16, 25, and 35 MPa. The pump supports host PLC or independent controller operation and can be configured with circulation detection and additional monitoring options.
The GET series also supports N68 lubricating oil and NLGI 000–2 grease, offering flexibility for applications with different lubricant requirements.
Step 3: Configure PLC Control and Feedback Signals
After selecting the pump, define how it will communicate with the machine's control system.
A typical control sequence includes:
The PLC receives a machine-running signal.
The PLC starts the lubrication pump according to the preset lubrication interval.
The pump delivers oil or grease through the distribution network.
Pressure, cycle detection, or other available feedback signals are monitored.
If an abnormal condition occurs, the PLC generates an alarm or initiates a predefined response.
The PLC can use these feedback signals to generate alarms or execute predefined responses when abnormal conditions are detected.
The electrical contact type, normally open (NO) or normally closed (NC), as well as NPN or PNP output configuration, should be confirmed according to the specific pump model and PLC input requirements.
The specific feedback configuration depends on the pump model. For example, BAOTN's oil lubrication pumps can provide optional liquid-level and pressure-switch signals. The GET grease pump supports pulse-based circulation detection and optional pressure and low-level monitoring.
For progressive systems, cycle detection is particularly useful because it helps confirm distributor movement and identify interruptions in the lubrication cycle.
Importantly, pump control and system monitoring should be considered separately. A pump that supports PLC-controlled operation does not automatically provide every monitoring function. The required sensors, electrical contacts, and PLC input/output configuration should be confirmed during system design.
Understanding PLC Control and Feedback Signals
In a typical centralized lubrication system, the PLC and lubrication pump work together through control and feedback signals.
Pump Start/Stop Signal: The machine PLC sends a control command to start or stop the lubrication pump according to the preset lubrication cycle.
Low-Level Signal: A level switch monitors the lubricant level in the reservoir and sends a signal to the PLC when the lubricant is insufficient.
Pressure Signal: An optional pressure switch monitors whether the system reaches the required pressure condition.
Cycle Detection Signal: In progressive lubrication systems, a cycle detection switch sends pulse signals to help the PLC verify distributor operation.
The PLC can use these feedback signals to generate alarms or execute predefined responses when abnormal conditions are detected.
The electrical contact type, normally open (NO) or normally closed (NC), as well as NPN or PNP output configuration, should be confirmed according to the specific pump model and PLC input requirements.
Step 4: Protect the Lubrication Network
Reliable lubrication depends on more than pump performance.
Pipelines should be correctly sized and securely connected to prevent leakage and pressure loss. Distributors must match the selected lubrication system, while lubricant cleanliness and viscosity should be appropriate for the operating environment.
Pressure regulation and overload protection are also important, particularly in high-pressure grease applications. For example, the GET series incorporates a pressure regulating valve to maintain the configured working pressure and protect the system.
During installation, all pipelines should be properly cut, connected, and secured to prevent lubricant leakage and pressure loss. The internal passages of the pipes should remain clean to avoid contamination or blockage.
The distributor must be compatible with the selected lubrication system. For example, volumetric oil lubrication systems require compatible metering distributors, while progressive grease lubrication systems should use matching progressive distributors.
Before commissioning, check the pipeline connections, lubricant level, pump operation, pressure settings, and feedback signals. A complete test should confirm that lubricant reaches all designated lubrication points and that the PLC receives the expected monitoring signals.
How to Choose the Right PLC-Controlled Lubrication System
Choosing between an oil and grease lubrication system depends on the lubricant required by the machine components and the design of the lubrication network.
Choose a PLC-Controlled Oil Lubrication System When:
Machine components require lubricating oil rather than grease.
The system uses volumetric distributors to deliver measured oil quantities.
Multiple lubrication points require synchronized oil supply.
The application involves longer main oil pipelines or relatively high oil consumption.
BAOTN BTA-C2 is suitable for small and medium-sized machinery with up to 50 lubrication points and a main oil pipeline length of approximately 25 meters. BTB-C2 and BTD-C2 can be evaluated for applications requiring longer pipelines and larger oil supply volumes.
Choose a PLC-Controlled Grease Lubrication System When:
Machine components require grease lubrication.
Bearings, guide rails, and sliding components need periodic grease replenishment.
A progressive distributor network is suitable for the application.
The system requires pressure regulation and lubrication cycle monitoring.
BAOTN GEN-1 and GEO-1 are options for general industrial machinery and CNC applications. GET is suitable for applications requiring higher pressure ratings and flexible lubricant and outlet configurations.
Before making the final selection, engineers should confirm the lubricant type, number of lubrication points, required lubricant quantity, pipeline length, working pressure, distributor type, and PLC interface.
Why Choose BAOTN for PLC-Controlled Lubrication Solutions?
BAOTN specializes in electric lubrication pumps and centralized lubrication systems for industrial machinery and automation equipment.
Our product portfolio covers volumetric oil lubrication and progressive grease lubrication solutions, providing different configurations for CNC machines, machining centers, automated production lines, conveyors, and other industrial applications.
Oil and Grease Lubrication Solutions
BAOTN offers different pump models for oil and grease applications, helping customers select a lubrication solution based on their lubricant requirements and distribution system.
PLC-Compatible Control Options
Selected BAOTN lubrication pumps support control through the host machine PLC or an independent controller. Depending on the model, monitoring options such as liquid-level switches, pressure switches, and cycle detection devices can be configured.
Application-Based Product Selection
Rather than selecting a pump based only on its model or rated pressure, BAOTN recommends evaluating the complete lubrication system, including lubricant type, lubrication point quantity, delivery requirements, pipeline layout, and control interface.
Whether you are designing a new machine or upgrading an existing lubrication system, BAOTN can help you evaluate a suitable pump and distribution configuration.
Contact BAOTN for Your Lubrication System Requirements
To help us recommend a suitable solution, please provide:
Machine type and application
Lubricant type and viscosity or grease grade
Number of lubrication points
Required lubricant quantity per point
Main pipeline length and layout
Required working pressure
PLC control voltage and feedback signal requirements
Contact BAOTN to discuss your centralized lubrication system design and pump selection requirements.
