The Cause of Mysterious Machine Shutdowns
A tenant at an industrial park was experiencing recurring voltage-related problems. The machines were shutting down mainly in the early morning with low-voltage fault alarms, while the tenant’s site was located several kilometres from the electrical supply point.
Continuous measurement installed at the supply point revealed that the voltage dropped to around 223 V at approximately 5 a.m. every day.
The problem could therefore be clearly identified and linked to the reported machine faults.
After the transformer tap setting was adjusted, the voltage-related problems disappeared.
The starting point
There had been a long-running disagreement between the operator of an industrial park and one of its tenants, located approximately 2.5 km from the supply point, about the cause of recurring electrical problems.
The tenant’s machines would periodically shut down, mainly in the early morning, with:
low-voltage fault alarms.
Because the problem occurred only intermittently, a one-time on-site measurement made it difficult to establish whether the supply voltage was actually responsible.
The key question was:
Does the voltage really drop at the same time as the machines report the fault?
What did we measure?
During the investigation, OMS24 Zrt. continuously monitored the voltage on the 0.4 kV side of the industrial park’s transformer station.
Continuous measurement was essential because the problem occurred only during a relatively short and specific period.
The data revealed a remarkably consistent pattern:
every day at around 5 a.m., the voltage dropped to approximately 223 V.
This coincided with the times when the tenant reported machine faults.
What did the measurement reveal?
Early-morning voltage drop and machine faults identified – OMS24 Zrt.
The most important part of the chart is the early-morning period.
The voltage was not continuously low.
During the day, the system could operate normally, meaning that a conventional daytime site inspection might easily have suggested that everything was in order.
The measurement profile, however, showed the same recurring pattern:
at around 5 a.m., the voltage dropped and then recovered later.
This explained why the machines reported low-voltage faults specifically during those early-morning hours.
What was causing the problem?
The measurements confirmed that the machine faults experienced by the tenant were associated with a genuine voltage drop.
The relatively low voltage measured at the supply point, combined with the additional voltage drop along the approximately 2.5 km electrical network, likely resulted in a voltage level at the tenant’s point of use that the machines could no longer tolerate.
The problem was therefore not a random machine failure.
Nor was the poor supply quality simply a matter of perception.
The measurement data clearly linked the machine faults to the recurring early-morning voltage drop.
This was particularly important because from that point onwards, the discussion no longer had to rely on assumptions.
There was measurable evidence.
What did we change?
To resolve the problem, the transformer tap setting was adjusted to increase the outgoing voltage level.
This brought the supply voltage into a more suitable operating range and eliminated the early-morning condition that had previously caused the machines to trip on low voltage.
There was no need to replace the tenant’s machines.
There was no need to continue a lengthy trial-and-error troubleshooting process.
The measurement showed exactly where corrective action was needed.
The result
After the transformer tap setting was adjusted:
the tenant’s voltage complaints ceased;
the low-voltage machine faults were eliminated;
more stable operation was restored.
In this case, the value of measurement was not expressed in saved kilowatt-hours.
Its value was that a recurring and difficult-to-identify operational fault became measurable, traceable and verifiable.
What does this case show?
Energy measurement is not only about determining how much electricity a piece of equipment consumes.
A suitable measurement system can also monitor other electrical parameters, including current, voltage and power.
This is particularly valuable for faults that occur:
only at certain times of day;
only for short periods;
or only under specific network conditions.
What we do not measure is easy to argue about. What we measure can become the basis for a technical decision.
Do you have recurring electrical faults whose cause remains unclear?
Continuous measurement can reveal intermittent network problems that may never appear during a conventional one-time site inspection.