FANUC robot preventive maintenance: what it includes, how often, and what to do when the cell stops overnight

Say it’s the third shift, 3:40 a.m. The cell stops and the teach pendant shows SRVO-062 BZAL. According to the FANUC R-30iB controller manual (B-83195EN/08, February 2016), that alarm means the battery backing up the absolute position has run dry, and the recovery includes replacing it and mastering again. Before that night there was a warning: SRVO-065 BLAL, low voltage. FANUC robot preventive maintenance exists so you deal with that warning during the day. On the M-410iB/140H they are 4 D-cell batteries, and FANUC America estimates them at about US$10 (December 3, 2020).

What FANUC robot preventive maintenance includes

We use the M-410iB/140H manual, for a palletizing robot, as our reference (B-83164EN/04, March 2017). The M-20iB manual (B-83754EN/03, September 2018) uses the same scale with differences by axis, and the MaintainX procedures for the M-410iC/185 repeat the 11,520 and 15,360 hours. FANUC asks you to meet whichever comes first, time or hours. Use the Appendix A table in your own model’s manual.

The 3-shift column is a Target Robotics calculation with assumptions: 24 hours, 6 days and 50 weeks give 144 hours per week and 7,200 per year, with the robot running that entire time. The 1-year lines are also done once at 3 months, the first time only.

How often, if your robot runs 3 shifts?

The table assumes up to 3,840 hours of use per year. Above that, FANUC asks you to shorten it in proportion: at 7,680 hours, double the frequency. At 7,200 hours, the frequency goes up 1.9 times (Target Robotics calculation), and the 3-year grease change arrives at 80 weeks. At 3 shifts, the calendar printed in the manual runs too long.

The batteries come with a discrepancy you should know about. The table puts them at 1.5 years and the text in the same section says every year; the M-20iB manual repeats that difference, and FANUC America talks about an annual change (2020). At 3 shifts, with the same proportion of hours, the 1.5 years come to 40 weeks and the annual change to about 27. Go with the shorter interval, and also replace them as soon as the low-voltage alarm appears. They get swapped with the controller on and the emergency stop pressed. The controller battery, on the main board, goes every 4 years; it holds the memory with programs and system variables, and FANUC recommends backing up before replacing it (B-83195EN/08).

Grease is the heaviest job. On the M-410iB/140H it means 10.3 kg of VIGOGREASE RE0 across the reducers, J4 gearbox and wrist, plus 20 ml of Alvania S2 at each of the 2 points on the J2/J3 bearing (B-83164EN/04). The manual calls for opening the outlet before injecting, using a hand pump or air at no more than 0.15 MPa, and running the robot for 20 minutes at 50% to release pressure, 40 for the wrist. Hot grease can burst out, so wear a face shield and heat-resistant gloves.

Two more signs. If very little old grease comes out, suspect a damaged seal. And if your robot has a cooling fan for a high duty cycle, the grease interval drops by half. In a guide for welding robots, FANUC America adds that dark grease suggests heat or contamination (2019, updated 2026).

How many labor hours does each robot take per year?

Appendix A of the same manual assigns time to each task: 0.1 hours to change batteries, 0.8 hours for J1 grease, 2 hours to retighten the main bolts, 4 hours to replace the mechanical unit cable. Added up by frequency, they come to about 8.6 hours per year at 3,840 hours of use and about 16 hours at 7,200.

That is a Target Robotics calculation with assumptions. It counts only the time in the table and leaves out travel, daily checks, mastering after a cable change, gripper, conveyors and downtime. For contrast, the Target Robotics annual contract allows about 20 hours per year per robot (Target’s leadership, 2026). If you are offered a preventive plan with few hours for a robot on 3 shifts, ask which lines are left out.

What do I do if the robot stops in the middle of the night?

People first. Nobody enters the cell with the robot energized: for maintenance, FANUC calls for shutting down and locking out, and if work with power on is needed, emergency stop pressed, a visible notice and a clear escape route (B-83164EN/04). NOM-004-STPS-1999 requires energy lockout before and during maintenance, with tags and padlocks (section 7.2.2, DOF, the official gazette, 1999). Palletizing cell safety requirements has more detail.

Then the data. Take a photo of the alarm screen and note what the robot was doing and which layer it was on.

The alarms come from B-83195EN/08 (2016) and B-83164EN/04 (2017). The “who acts” column is Target Robotics’ judgment: adjust it to your safety program and to the training each person has. Jumpering the door signal to keep producing is ruled out; the controller manual calls it very dangerous.

If you are going to call service, have on hand what FANUC America asks for: the robot’s F# or serial number, symptoms, error codes, diagnostic LEDs, parts in stock and the arrival time you need (checked November 3, 2026). After replacing a part, the manual calls for a test with personnel outside the fence.

What should be ready before 3 a.m.

• Controller backup on a memory card or USB, stored outside the cabinet, plus the mastering data. FANUC asks for periodic backups (B-83164EN/04).
• Spare batteries with their part number: A98L-0031-0005 on the M-410iB/140H.
• Brake release unit, A05B-2450-J350 for 100 to 115 V or J351 for 200 to 240 V. FANUC asks that it be available and within reach from installation onward, to move axes without power in an emergency, such as a trapped person. It is used as the controller manual describes, and moving the robot this way can require mastering afterward (SRVO-038).
• Fuses and spare parts recommended by FANUC. The manual warns of fire risk with other fuses.
• Someone trained on every shift. Target Academy includes a one-week course with the machine, in its own lab, in groups of 6. For maintenance teams it also teaches the R-30iB controller and R-2000 mechanical teardown courses, and for programmers, the basic and advanced ones.

Everything on this list gets bought and tested during the day. If the robot is used, also review what to check on a used robotic palletizer.

What to get in writing in a maintenance contract

The Target Robotics annual 24/7 maintenance contract includes preventive and corrective maintenance, training and spare parts, with more than US$100,000 in robot spare parts (corporate presentation, 2026). FANUC America offers preventive maintenance and service contracts in Mexico (checked November 3, 2026). Whoever your supplier is, us included, ask for this in the contract:

• Remote and on-site response time, by severity and with your city written in.
• Who answers at 3:40 a.m. and in what language.
• Which interval table they use and how they adjust it to your operating hours.
• Which spare parts they have in Mexico and how long those take to arrive.
• How they hand you the record. Section 7.2.3 of NOM-004 requires a dated record of preventive and corrective maintenance, kept for at least 12 months, and the guide from the STPS, Mexico’s federal labor ministry (December 2022), repeats it.

For budgeting, the public references come from vendors in the United States: Automation Distribution, undated, talks about 3 to 5% per year of the system price for cobots, and Standard Bots, in its 2026 guide, about US$3,000 to US$7,000 per year. At 3 to 5%, a US$100,000 cell comes to US$3,000 to US$5,000 (Target Robotics calculation). Add it in the payback calculator with Mexican wages.

Start with one sheet per robot: how many hours it has, when the batteries were changed and where its latest backup is. If you do not know which manual applies to you, the spec sheet and controller for your model tell you which one to ask for.