To monitor a standby generator remotely, connect its controller (usually over Modbus) and a fuel level sensor to a gateway that reports over GSM or the site network to a monitoring platform. Track running status, mains and ATS state, run-hours, fuel level, battery voltage, output and alarms, and send alerts for failed starts, low fuel, sudden fuel drops and battery faults.
Why monitor generators remotely?
In South Africa, standby generators are often run hard for extended periods and then left idle for months. The failure that matters is the one you discover when the power goes: a flat battery, an empty tank or a controller alarm nobody saw. Remote monitoring shows the condition of every generator continuously and alerts someone before an outage exposes the problem.
What to measure
| Signal | Source | What it tells you |
|---|---|---|
| Running / stopped / fault | Controller | Whether it started and is healthy |
| Mains available / failed | Controller or ATS | When outages start and end |
| ATS position | ATS auxiliary contact | Whether the generator actually took the load |
| Run-hours and number of starts | Controller | Service planning |
| Fuel level (litres) | Fuel level sensor | Refuelling, consumption and loss |
| Battery voltage | Controller or analogue input | Starting reliability |
| Output V, A, kW | Controller or meter | Load and overload risk |
| Coolant temperature, oil pressure alarms | Controller | Engine protection events |
Connecting the generator
Most modern generator controllers — including widely used Deep Sea and ComAp models — provide data over Modbus RTU or Modbus TCP, either built in or through a communications module. A gateway reads the controller’s registers and sends them to the monitoring platform. On older sets without communications, the same picture can be built from digital inputs (running, fault, mains fail) and analogue inputs (battery voltage, fuel sensor).
Controller fuel readings are often a rough percentage from a float sender. A dedicated capacitive or ultrasonic fuel sensor, calibrated to the tank dimensions, gives actual litres — which makes consumption tracking and theft detection reliable.
Connectivity during outages
The moment you most need data — a mains failure — is also when site networks and routers may go down. Power the gateway from the generator’s battery supply or a small UPS, use GSM/LTE as the primary or backup link, and make sure the gateway buffers readings so the full outage is recorded even if the link drops.
Alerts that matter
- Mains failed but generator not running within the expected start time.
- Generator running but ATS not transferred — the load is still off.
- Low fuel with enough margin to arrange delivery.
- Sudden fuel drop while stopped — likely theft or a leak.
- Low battery voltage or charger failure.
- Service due by run-hours or calendar.
- Gateway offline — so silence is never mistaken for health.
Monitoring a fleet
For property portfolios, healthcare groups and multi-site businesses, all generators report into one platform with a fleet view: status, fuel and alarms per site, run-hours per month and fuel consumed per outage. Combined with energy monitoring, the same dashboard can show mains consumption and generator supply side by side.