Executive summary

This analysis compares the 5-year total cost of ownership (TCO) of two 24 V DC circuit protection schemes in a representative 50-channel industrial cabinet: conventional gG fuses vs. electronic fuses (eFuses) with LED signalling. The scenario assumes 6 fault events per year, a line downtime cost of €500/hour and technician labour at €65/hour. Result: the eFuse pays back its initial cost in 28 months and delivers a net saving of €7,994.50 over the 5-year horizon compared with the conventional fuse.

If you are new to this technology, we recommend starting with our introduction: what an electronic fuse (eFuse) is and why it is replacing conventional fuses in industrial control panels.

1. Definition of the analysis scenario

The analysis is based on an industrial installation representative of typical projects in the Spanish market: a production line with a control cabinet feeding 50 independent 24 V DC circuits (sensors, actuators, valves, small motors and drives). The scenario parameters are detailed below:

2. TCO of the conventional fuse

2.1 Initial investment costs

The material cost of protecting 50 channels with conventional fuses includes fuse holders, fuses of different ratings and the initial spare-parts stock:

2.2 Annual operating costs

Each conventional fuse fault event in this scenario involves three types of cost: diagnosis (locating the blown fuse), line downtime and fuse replacement. The average diagnosis time in a 50-circuit cabinet without fault signalling is 45 minutes.

3. TCO of the electronic fuse (eFuse)

3.1 Initial investment costs

Protecting 50 channels with eFuses requires 13 four-channel modules (12 full modules + 1 for the remaining 2 channels). A competitive module from the European market is used as the price reference (mid-to-high range, with per-channel LED signalling and adjustable current from 1 to 10 A):

3.2 Annual operating costs

With the eFuse installed, the diagnosis process changes radically. The red LED of the faulty channel is visible on the front of the module without opening the cabinet. In installations with SCADA, the digital alarm signal indicates the exact channel in the supervision system. The average diagnosis time drops to 8 minutes. Reset is manual (push-button) or automatic depending on configuration; this scenario assumes manual mode for greater operator control.

4. Comparison and return analysis

The eFuse pays back its additional investment of €2,488 (€3,100 − €612) in 28 months thanks to annual savings of €2,096.50 in diagnosis and downtime costs. From month 29 onwards, every euro invested in the eFuse generates €3.20 in return. The 5-year ROI is 221%.

5. Sensitivity of the result: when does the eFuse NOT pay off?

The analysis above assumes 6 fault events per year and a downtime cost of €500/hour. It is important to understand how the conclusion changes with different parameters:

The rule of thumb is as follows: if an installation with 50 circuits at 24 V DC suffers fewer than 2 fault events per year and the downtime cost is below €200/hour, the conventional fuse may be economically preferable over a 5-year horizon. In all other typical industrial scenarios, the eFuse is the more cost-effective option.

6. Methodology and limitations of the analysis

This analysis is based on a representative industrial scenario, not on a specific real installation. The unit prices of the eFuse modules are indicative and vary by manufacturer, purchase volume and channel agreement. The operating cost parameters (downtime, labour) are estimates based on Spanish industrial sector references for 2025–2026.

• Diagnosis costs assume a single technician working without additional remote diagnostic tools. Installing SCADA or an additional telemetry system would reduce diagnosis time with conventional fuses, changing the differential.
• The analysis does not include the benefits of selective protection (preventing a fault in one channel from affecting adjacent channels), which in high-criticality installations can represent significant additional value.
• Line downtime costs have the greatest influence on the final result. Each company should apply its own downtime cost to obtain an accurate estimate of its specific payback.