Automatic vs manual bearing lubrication: which to choose

The choice between manual and automatic bearing lubrication is often reduced to budget. It is more useful to look at point accessibility, machine criticality and what the system uses to decide "add grease": the calendar or the condition.

Three levels, not two

Approach	How it decides "when / how much"	Pros	Cons
Manual by calendar	A date in the procedure plus a grease gun	Cheap to start	Over- and under-greasing, human factor
Manual by condition	Friction/temperature measurement plus a grease gun	Precise dose, flexibility	Requires a route and discipline
Automatic by time (lubricator)	Timer / counter	Less manual labour	Still blind to condition
Automatic by condition	Ultrasound / algorithm → dose	24/7, no surplus strokes	Capital cost, integration

"Automatic" does not mean "smart". A lubricator that delivers a shot every N hours can steadily over-grease a quiet bearing.

When a manual programme is enough

Manual lubrication with a good point map is justified when:

• the points are accessible without risk or downtime;
• the fleet is large but criticality is moderate;
• you have trained lubricators and a logbook / CMMS;
• you are ready to move from calendar to condition.

The minimum quality bar for a manual route:

1. One grease brand per point (choosing a grease).
2. Clean greasing technique (instructions).
3. Stop on the drain / acoustics, not "one more stroke".
4. A history per point.

The tool for a precise manual dose is LUBExpert; for simple quality control, LUBEChecker.

When you need automation

Condition-based auto-lubrication makes sense when:

• the point is hard to reach or hazardous (height, ATEX, hot shop);
• the machine is critical and the route interval is longer than the grease degradation time;
• night and weekend shifts leave the route uncovered;
• failures have already occurred between planned greasings.

The logic in practice: fixed friction monitoring plus a controlled lubricator. In the SDT range that is LUBExpert ON-GUARD — see also ON-GUARD auto-lubrication and the pulp mill pump case.

The hybrid that works in practice

Most mature sites do not choose all-or-nothing:

• 80–90% of points — a manual route with acoustic control;
• the critical 10–20% — condition-based automation;
• calendar lubricators without feedback — only where the over-greasing risk is consciously accepted and checked by inspection.

For pumps and fans see pump and fan lubrication; for conveyors — idlers.

How to decide in one conversation

1. List lubrication-related failures over the last 12–24 months.
2. Map accessibility × criticality.
3. Pilot: one critical point on ON-GUARD, or 50 points on manual LUBExpert.
4. KPIs: grease consumption, number of overheats, unplanned bearing replacements.

KEG TRK will design the scheme for your fleet in Kazakhstan. Request.