An hour meter (horímetro) records how long a machine has actually run, and that figure is the most direct basis for deciding when a pump, compressor, generator or motor needs service. The meter only produces the number. The value comes from what happens next: a service interval tied to the reading, a work order raised when it is reached, and a record that shows what was done. In our view, the best results come from keeping the reading, the schedule and the work order in one system, which is what FullyOps is built for.
TL;DR
- An hour meter accumulates the time a machine is powered or running. It works like the odometer of the machine, which is why it suits wear that depends on use rather than on the calendar.
- Choose by supply voltage and type (AC or DC), display, accuracy, protection rating and counting principle. Vibration-activated models need no wiring.
- Connect it to the circuit that drives the load, after the contactor, and match the frequency to your grid: a 50 Hz meter on a 60 Hz supply over-counts by 20%.
- Engine hours are not productive hours, and a meter does not measure condition. Combine hours-based intervals with inspections.
- Hours only pay off when each reading triggers a scheduled work order and lands in the asset history.
Índice
- What an hour meter measures
- Why hours beat the calendar for maintenance planning
- How to choose an hour meter
- Installing the hour meter so it records reliably
- Turning readings into service intervals
- Managing hours across many assets
- Our perspective
- Bring your hours into one maintenance workflow
- PREGUNTAS FRECUENTES
- Fuentes
What an hour meter measures
An hour meter counts elapsed operating time. Honeywell describes it as a device that records elapsed time, normally in hours and tenths, mainly for maintaining motors, fans, blowers and similar machines. Weschler lists the typical uses: tracking utilisation, scheduled maintenance, warranties and rentals.
There are two principles to understand:
- Electromechanical (analogue): it advances while it receives voltage and stops when the machine switches off. According to Alpes Automação, the reading stays on the display with no programming and no battery.
- Digital: it measures the time during which an input is active. Weschler notes that electronic models usually have an LCD and non-volatile memory, while electromechanical ones use a clockwork movement and a simple two-wire connection.
In practice, the meter counts the time during which there is voltage across its terminals. CELSA explains that this is why it is wired in parallel with the motor, pump, compressor or contactor that controls operation.
Why hours beat the calendar for maintenance planning
Most maintenance plans use operating hours as the reference for inspections, component replacements and periodic overhauls. The reasoning is simple. A compressor that runs 20 hours a day wears differently from an identical unit that runs 20 hours a week. A calendar-based plan services both at the same interval, so one is serviced too early and the other too late.
Honeywell recommends using real running time rather than calendar days or distance alone, because it correlates better with operating life and reduces uncertainty about when maintenance is due. Industry vendors apply the same logic to connected equipment: DoPapel reported in 2026 that Tecnau’s monitoring platform uses operating hours, cycles and other usage data to anticipate preventive interventions.
What an hour meter does not tell you
Two points keep the reading honest.
First, engine hours are not the same as productive hours. TECNNIC distinguishes effective working time from idle time, and notes that separating the two improves operational interpretation and planning. A generator that idles for six hours has accumulated wear, but not the same wear as six hours under load.
Second, a meter does not measure condition. The EN 13306 maintenance terminology standard, in the summary published by the Standards Institute of Slovenia, separates predetermined maintenance, based on intervals or units of use, from condition-based maintenance. An hour meter supports the first. For critical assets, pair it with inspections and condition checks, and record both in the same asset history.
How to choose an hour meter
The right model depends on the machine, the supply and where the meter will sit. eibabo.pt recommends weighing the type of installation, voltage range, form of indication, accuracy, protection rating, connection and counting principle. Here is how that translates for a maintenance team.
| Criterion | What to check | Typical consequence |
|---|---|---|
| Supply | Voltage (for example 230 V AC or 24 V DC), AC or DC, frequency | A mismatch gives wrong counts or damages the unit |
| Display | Digital when the reading must be visible and easy to export; mechanical for classic applications and durability | Affects how technicians read and record hours |
| Counting principle | Voltage-based or vibration-based | Decides whether you need a wired connection |
| Protection rating | Sealed construction for outdoor, dusty or wet locations | Reliability on mobile and outdoor plant |
| Range and resolution | Maximum hours and decimal resolution | Fleet-wide comparison and long asset lives |
Digital, analogue and vibration-activated models
eibabo.pt distinguishes digital counters, suited when a clearly visible reading is needed, from mechanical ones, often chosen for classic applications and durability.
Vibration-activated meters suit machines with no convenient electrical connection. The HCP-Technology VBZ1, for example, records the time the machine vibrates, has a range from 0.001 to 999,999.0 hours and a sealed construction for outdoor use. That makes this type practical for tractors, mobile plant and equipment where tapping into the supply is awkward.
A simple rule: use a voltage-based meter wherever there is a clean circuit that only energises when the machine does real work, and a vibration-based one where there is not.
Installing the hour meter so it records reliably
Most bad hour data comes from installation, not from the device. Follow this sequence.
- Pick the right circuit. Alpes Automação advises connecting the meter to the circuit that drives the motor or main load, after the contactor, and not to the general supply. If you connect to the general supply, the meter counts hours the machine is merely powered, not running.
- Match the electrical data. Confirm voltage, AC or DC and frequency against the meter’s label before wiring.
- Respect polarity on DC. CELSA states that polarity must be observed on direct current, while AC connections have no polarity.
- Check the frequency. Alpes Automação warns that a 50 Hz meter on a 60 Hz network counts 20% more, so the device frequency must match the installation. The mains in Portugal is 50 Hz, but imported machines and generators built for other markets are worth checking.
- Mount it where it can be read. The meter belongs on the equipment panel or wherever the operator and technician can see it easily. eibabo.pt notes that counters can be fitted in building installations, electrical panels or individual appliances.
- Record the starting value. Write down the initial reading, the date and the asset it belongs to. A replacement meter restarts at zero, so note the old value and the swap date, otherwise the asset history breaks.
Electrical work on panels should be done by a qualified electrician, in line with your site’s safety procedures.
Turning readings into service intervals
This is the step most teams do informally and where the hour meter either pays off or becomes decoration.
Set the interval from the manufacturer, then adjust
Start with the manufacturer’s service interval in hours for each task (oil and filter change, belt inspection, bearing lubrication, overhaul). Express each as “every N hours” and attach it to the asset, not to a person’s memory. After a few cycles, review failure and inspection findings and tighten or relax the interval accordingly.
Worked example
A site has three compressors with a 500-hour oil and filter service.
| Activo | Last service at | Reading now | Next due at | Hours remaining |
|---|---|---|---|---|
| Compressor A | 4,200 h | 4,620 h | 4,700 h | 80 h |
| Compressor B | 3,100 h | 3,150 h | 3,600 h | 450 h |
| Compressor C | 5,900 h | 6,420 h | 6,400 h | overdue by 20 h |
On a calendar plan, all three would be serviced on the same day. By hours, C is already overdue, A needs scheduling this week and B can wait. The same reading, expressed as hours remaining, also tells you how many days you have, once you know the daily running time of each machine. This is an illustration with invented figures, not a recommended interval.
Make every threshold generate a work order
The weak point is the handover from “the meter says 4,700” to “someone is assigned and the job is done”. A workable routine has four parts:
- a fixed reading frequency (per shift, weekly or at each visit);
- a threshold per task, with a warning margin before it is due;
- a work order created and assigned when the margin is reached;
- a closing entry with the reading at service, the parts used and the technician’s time.
Done on paper or spreadsheets, this depends on someone remembering to compare readings with thresholds across dozens of assets. Done in a maintenance platform, scheduling, assignment and history sit together. Our guides on the work order management process to reduce downtime and the five-stage work order workflow cover the routine in detail, and why tracking maintenance hours matters explains the cost side.
Keep hours and condition in the same record
Because hours do not show condition, log inspection findings next to the hours at which they were made. Over time you can see, for example, that bearings on a given pump show wear at 3,000 hours and not at 5,000, and move the interval. For standby equipment such as generators and pumps, which run few hours but must start on demand, generator runtime monitoring shows how runtime tracking connects with scheduled maintenance.
Managing hours across many assets
With five machines, a notebook works. With fifty, the problems are consistent:
- Different meter types and units. Some assets show hours and tenths, others only whole hours. Standardise how readings are written.
- Missed readings. If technicians must walk to every panel, gaps appear. Collect readings during routine rounds and service visits, from the field, at the time of the job.
- Unclear responsibility. Decide who reads, who validates and who schedules. User roles and permissions help here: technicians enter readings, supervisors approve, managers see the totals.
- No view across the fleet. Managers need hours remaining by asset, overdue tasks and parts needed for the next services. See our guides on rastreo de activos y seguimiento de inventario para mantenimiento for the surrounding routines.
The parts side matters as much as the schedule. A 500-hour service that is due but has no filters in stock is still a delay, so linking upcoming services to inventory removes one common cause of overdue work.
Our perspective
Maintenance teams rarely fail because they lack a number. They fail because the number lives in one place, the schedule in another and the history in a third. An hour meter is a cheap, reliable source of truth about use, and it deserves a system that acts on it.
At FullyOps we combine asset lifecycle management, work order control, operational analytics and field data collection in a single platform built for industrial, facility and maintenance use. That means the asset, its preventive maintenance schedule, the work orders and the technicians’ records are in the same place, with plans for technicians, administrators and managers and integrations with other systems.
Our advice is to start small: choose your ten most critical assets, define one hours-based task for each, and run the full loop from reading to closed work order for a quarter. Then widen it. The routine matters more than the device.
Pedro
Bring your hours into one maintenance workflow
If your team already reads hour meters but still chases due dates by hand, FullyOps brings preventive maintenance scheduling, work order management, inventory and reporting into one cloud platform, with Basic, Professional and Advanced plans for different team sizes and roles. You can see the plans on the Sitio de FullyOps and explore how gestión de servicios de campo works across a team.
PREGUNTAS FRECUENTES
What is the difference between an analogue and a digital hour meter?
An analogue (electromechanical) meter advances while it receives voltage and holds its reading without a battery. A digital meter measures the time an input is active, usually shows it on an LCD and stores it in non-volatile memory. Choose by how the reading will be viewed and recorded, and by the supply and environment.
Where should I connect an hour meter?
Connect it to the circuit that drives the motor or main load, after the contactor, so that it only counts when the machine runs. Confirm voltage, AC or DC and frequency first, and respect polarity on DC. A qualified electrician should do the wiring.
Can I use an hour meter on a machine with no electrical connection?
Yes. A vibration-activated model records the time the machine vibrates and needs no wiring. Some versions are sealed for outdoor use and cover a very wide range of hours, which suits tractors and mobile plant.
Is an hour meter enough to plan all maintenance?
It is the right basis for interval-based tasks, but it does not measure condition. Record inspection findings next to the hours at which they were made, so intervals can be adjusted from real evidence.
Fuentes
- Specifying Hour Meters, Honeywell
- Horímetro analógico e industrial, Alpes Automação
- Hour Meters: Function, Connection 230 V / 24 V DC, Mounting, CELSA
- Elapsed Time Meters: Applications, Benefits, and Industrial Uses, Weschler
- Tecnau reforça aposta no Connect, DoPapel
- Telemetria embarcada, TECNNIC
- SIST EN 13306:2010 summary
- Contadores de horas de funcionamento, eibabo.pt
- Vibration hour meter VBZ1, HCP-Technology
- Generator monitoring best practices, PODTECH
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- Por qué registrar las horas de mantenimiento: reducir costos y aumentar la eficiencia
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- Por qué realizar un seguimiento de las horas de los técnicos: la guía del gerente de operaciones
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Mejore sus operaciones y maximice la eficiencia con FullyOps
- Para equipos de mantenimiento
- Garantice la fluidez de las operaciones con una gestión automatizada de las órdenes de trabajo, un seguimiento en tiempo real y una coordinación perfecta entre los equipos.
- Para proveedores de servicios
- Optimice la eficiencia del servicio de campo con una programación inteligente, planificación de recursos y herramientas móviles para la gestión sobre la marcha.
- Para gestores de activos
- Obtenga una visibilidad completa de los ciclos de vida de los activos, los programas de mantenimiento preventivo y el seguimiento del cumplimiento, todo en un mismo lugar.