In tropical countries such as Vietnam, Indonesia, Malaysia, Thailand and the Philippines, switchgear operates in conditions that accelerate insulation ageing: high ambient temperature, high relative humidity, frequent condensation and, in coastal areas, salt-laden air. These conditions do not merely shorten equipment life – they actively drive the partial discharge (PD) mechanisms that lead to failures.
The mechanisms: how the tropics attack insulation
Temperature and heat concentration
Ambient temperatures of 30-40°C, combined with load heat inside switchgear, push insulation closer to its thermal limits. Higher temperature raises the probability of PD activity for a given stress level, and prolonged heat accelerates ageing of organic insulation materials.
Humidity and condensation
When warm humid air enters switchgear and meets cooler surfaces, condensation forms. Moisture on insulation surfaces promotes surface discharges and tracking, and can reduce the insulation strength of creepage paths. In unsealed or poorly sealed cubicles this is a year-round condition in tropical climates, not a seasonal one.
Salt and pollution
Near the coast, salt-laden air deposits on insulator surfaces and reduces their flashover strength, creating surface discharge activity that handheld surveys often pick up as persistent TEV signals.
What to monitor in a tropical environment
- TEV sensors – detect surface discharges on switchgear panels, the most common PD mechanism under humid conditions; mount on the cable compartment or busbar chamber.
- Ultrasonic sensors – pick up surface discharge and tracking as airborne ultrasound, useful in open-air and cable compartments.
- UHF sensors – for enclosed GIS and metal-clad switchgear where PD radiates as electromagnetic waves inside the compartment.
- HFCT – clamp-on sensors for PD on cables and cable terminations, where tropical moisture attacks termination insulation.
- Environmental parameters – temperature and humidity readings correlated with PD trends reveal whether activity rises with condensation events, helping crews time inspections.
Why online monitoring beats periodic surveys in the tropics
Condensation-driven PD can appear and disappear with weather and loading. A periodic survey may simply miss the worst hours. Continuous online monitoring records activity around the clock, so the correlation between humidity spikes and PD peaks becomes visible – and maintenance can be scheduled before tracking develops into a fault.
A monitoring configuration for tropical switchgear
A typical HUWOR deployment for a distribution substation in a tropical climate combines:
- TEV sensors on cable compartments of critical feeders
- Ultrasonic sensors in cable chambers where surface discharge is expected
- An IoT gateway collecting PD, temperature and humidity data
- The SCMP platform trending activity and raising alarms on rising trends
About HUWOR
Zhuhai Huawang Technology Co., Ltd. (HUWOR) is a Chinese national high-tech enterprise founded in 2010, specialising in PD monitoring, live-line detection instruments and online condition monitoring systems. The company supports utilities, EPC contractors and OEM/ODM partners across Southeast Asia. Contact the HUWOR sales team for sensor selection and deployment support in your country.