⚠️ Disclaimer: These tasks are guidelines only. They do not include lockout/tagout (LOTO), energy isolation, or other safety requirements. Review and verify suitability for your specific equipment and application. Add all required safety procedures per your company's policies and regulatory requirements before use. You are responsible for the safe and appropriate execution of all maintenance activities.
Industrial counters are simple until they're not. They count parts, cycles, batches, events — and nobody thinks about them until a count is wrong, a batch is off, or a relay that was supposed to fire at 500 didn't. By then you're not just troubleshooting a counter. You're auditing everything downstream of it.
This checklist covers visual inspection, operational verification, electrical checks, mechanical inspection, and configuration integrity for industrial counters. It is built for maintenance technicians executing PMs and maintenance managers building or reviewing PM programs.
For broader context on maintaining the control systems these counters live inside, see electric motor and control system PM fundamentals.
How to Use This Checklist
Record findings with specifics, not checkmarks. "Display legible" tells you nothing six months from now. "Left digit dim — fading progressively over last three PMs" tells you replacement is due before the next PM cycle.
Trend your measurements. Supply voltage should be consistent. If it's drifting toward the low end of the manufacturer's spec each quarter, something upstream is changing. A single measurement is a data point. Three measurements over time are a pattern.
Know the difference between a real finding and a cleared checkbox. A bad finding looks like: "Reset tested — counter returned to 0 on manual reset but failed to reset via remote input — traced to loose terminal on reset input." A checkbox answer looks like: "Reset OK." One of those findings creates a work order. The other one disappears.
Visual Inspection
Field Checklist — Critical Tasks
| Task | Freq | Type |
|---|---|---|
| Inspect counter housing and mounting hardware for cracks, corrosion, or looseness. Tighten any loose fasteners. | Monthly | ALL |
| Inspect the display or dial face for legibility — confirm digits/characters are readable and not faded, cracked, or obscured. | Every PM | ALL |
| Clean the counter housing, display lens, and surrounding area of dust, oil, and debris using appropriate cleaner. Do not use solvents on plastic lenses. | Monthly | ALL |
| Verify counter enclosure seal and gasket integrity — confirm cover closes fully and there are no gaps allowing moisture or contamination ingress. | Quarterly | MEC |
Reference Checklist — Full Task Library
| Task | Freq | Type |
|---|---|---|
| Inspect counter housing, mounting bracket, and enclosure for mechanical damage, corrosion, cracks, or loose fasteners. Tighten or replace hardware as needed. | Monthly | ALL |
| Verify display or register readability — check for digit dropout, fading, cracking, or condensation behind the lens. | Every PM | ALL |
| Inspect enclosure gasket and door seal integrity. Confirm IP/NEMA rating is maintained — replace gasket if compressed flat or damaged. | Semi-Annually | MEC |
| Clean interior of enclosure if accessible — remove dust or debris from circuit board and terminals using compressed air or appropriate brush. Ensure power is off (LOTO). | Semi-Annually | ELE |
Operational Checks
Field Checklist — Critical Tasks
| Task | Freq | Type |
|---|---|---|
| Verify the counter resets correctly to zero (or preset value) when the reset function is activated. | Every PM | ALL |
| Confirm the counter increments accurately by manually triggering or simulating the input signal and comparing the count to expected value. | Every PM | ALL |
Reference Checklist — Full Task Library
| Task | Freq | Type |
|---|---|---|
| Verify counter reset function operates correctly — test both manual reset and any automated/remote reset inputs. | Every PM | ALL |
| Test counting accuracy by simulating or manually triggering a known number of input pulses and confirming the counter registers the exact count. Investigate any discrepancy. | Monthly | ALL |
| Test all output functions: relay contacts, transistor outputs, alarm outputs, and batch control signals. Confirm correct operation at each count threshold. | Quarterly | ELE |
| Document current count totals and compare to production records or equipment runtime logs to identify any discrepancies indicating counting errors. | Monthly | ALL |
Mechanical Inspection
Field Checklist — Critical Tasks
| Task | Freq | Type |
|---|---|---|
| Inspect the sensor or input device feeding the counter (proximity switch, encoder, limit switch) for alignment, damage, and secure mounting. | Monthly | MEC |
Reference Checklist — Full Task Library
| Task | Freq | Type |
|---|---|---|
| Inspect the input sensing device (proximity sensor, encoder, limit switch, photoelectric) for alignment, target gap (if applicable), secure mounting, and absence of contamination. | Monthly | MEC |
| Verify target or actuation flag condition — inspect for wear, damage, or positional drift that could cause missed or false counts. | Quarterly | MEC |
| Inspect and test any mechanical totalizer or electromechanical register (if present) for smooth operation and accurate advancement without slipping or jamming. | Semi-Annually | MEC |
Electrical Inspection
Field Checklist — Critical Tasks
| Task | Freq | Type |
|---|---|---|
| Check all input wiring, connectors, and cable entries for signs of damage, abrasion, or loose connections. Reseat any loose connectors. | Monthly | ELE |
| Check indicator lights, alarm outputs, or relay contacts associated with the counter for correct operation if applicable. | Quarterly | ELE |
Reference Checklist — Full Task Library
| Task | Freq | Type |
|---|---|---|
| Inspect all input signal wiring, terminal connections, and cable glands for tightness, insulation damage, and correct strain relief. | Monthly | ELE |
| Measure supply voltage at counter terminals and confirm it is within the manufacturer's specified operating range (typically ±10% of rated voltage). | Quarterly | ELE |
| Test input signal quality — verify signal amplitude, frequency, and duty cycle from the triggering device are within counter specifications. Use a multimeter or oscilloscope as appropriate. | Quarterly | ELE |
| Verify backup battery condition if counter uses battery-backed memory (check voltage or replace per manufacturer interval, typically 1–3 years). | Annually | ELE |
| Confirm counter is correctly labeled, documentation (wiring diagrams, settings record) is current, and any PLC or SCADA integration is performing as expected. | Annually | ELE |
| Review counter preset values, batch settings, and configuration parameters against documented standards. Correct any unauthorized or incorrect changes. | Semi-Annually | ELE |
Failure Modes This Checklist Targets
Display degradation. Digit dropout and display fading happen gradually and get normalized. By the time someone notices a count is being read wrong, the error has been compounding across shifts. Legibility checks catch this before it becomes a process problem.
Counting errors from input signal issues. A counter that's mechanically fine will still miscount if the signal feeding it is weak, noisy, or out of spec. Proximity sensor drift, encoder contamination, and loose connections produce intermittent inputs that register as missed counts or phantom pulses. Signal quality checks find this. Counting accuracy tests confirm it.
Reset failures. Manual reset works. Remote reset doesn't. Or both appear to work during PM but fail under load when the automated sequence fires. Testing both reset paths — and both manually and under the actual control signal — is what catches the failure before a batch runs to completion on bad data.
Configuration drift. Preset values get changed. Somebody adjusts a threshold and doesn't document it. A technician resets the counter after a fault and doesn't restore the correct preset. Without periodic configuration audits, those changes accumulate silently until a batch is short or a relay fires at the wrong count.
Enclosure compromise. Counters mounted near washdown zones, heat sources, or vibrating machinery take ongoing punishment the housing wasn't always designed for. Gasket degradation, loosened covers, and cracked housings let in moisture and contamination that destroy electronics and display assemblies from the inside — slowly, then all at once.
Battery-backed memory loss. Counters with battery-backed memory lose their totals and settings when the battery dies. It doesn't fail dramatically. The counter just comes back from a power interruption with no presets, no accumulated totals, and no warning that anything was lost.
