More and more monitoring-system integrators, switchgear manufacturers and utility groups are sourcing partial discharge sensors on an OEM/ODM basis: the sensor is supplied under their brand, configured to their specification, and integrated into their platform. The quality of that arrangement depends almost entirely on how the supplier is qualified in the first place. This article is a practical checklist for evaluating a PD sensor manufacturer before signing the agreement.
1. Measurement capability and calibration
PD sensors are measurement devices, and the first question is whether the supplier can prove the numbers they quote:
- Are the frequency ranges (for example 300-1500 MHz for UHF, 0.5-30 MHz for HFCT) stated with the conditions under which they were measured?
- Is there a calibration procedure, and is a certificate available with each delivery?
- Does the supplier have the test equipment to verify sensitivity and linearity, or are the figures taken from design calculations?
2. Technology coverage
A single-technology supplier locks the buyer into that technology. A partner that manufactures the full family – TEV, UHF, ultrasonic, HFCT and combined sensors – makes it possible to source the whole sensor layer from one qualified partner and to change technology as project needs change. Check which technologies are manufactured in-house versus re-labelled from another factory.
3. Customisation depth
OEM/ODM only makes sense if the supplier can actually customise:
- Private labelling and packaging
- Custom cable lengths, connectors and housings
- Firmware changes and interface protocol adjustments (Modbus, RS485, LoRa)
- Integration with the buyer’s monitoring platform, or a documented open interface
Ask for examples of previous OEM projects and the typical lead time for a configuration change.
4. Field experience and references
PD monitoring is a field discipline, and the supplier’s experience shows in the details:
- Installation guidance – where sensors should and should not be placed
- Noise handling – how the design suppresses the interference that makes PD systems unusable
- Project references in utilities and industry, and the ability to provide case studies
5. Documentation and compliance
The documentation set should be complete enough to survive the relationship:
- Datasheets with stated measurement conditions
- Installation and commissioning manuals
- Declarations and certifications applicable to the target market
- Long-term availability commitment for the product and its spares
6. Support and lifecycle
PD sensors are installed for the life of the substation, which is longer than most product cycles:
- Is the supplier able to support the product for the expected service life?
- What happens if a sensor fails in year five – replacement policy and turnaround?
- Is there training for the buyer’s installation and commissioning teams?
Applying the checklist
Score each section against the supplier’s evidence, not their claims. A supplier that provides calibrated sensors, a documented customisation process, field references and a realistic support commitment is a partner; one that only offers the lowest price per unit is a transaction, and the cost of a failed monitoring system will be far larger than the saving.
About HUWOR as an OEM/ODM partner
Zhuhai Huawang Technology Co., Ltd. manufactures the full range of partial discharge sensors – TEV, UHF, ultrasonic, HFCT and combined types – plus handheld detectors, SF6 leak detectors, IoT gateways and monitoring systems, and supports OEM/ODM supply including private labelling, custom firmware and platform integration. Contact the HUWOR sales team for a qualification pack.