Skip to main content


9 gas on-line OLTC DGA expandable with add-ons to a Transformer Monitoring System (TMS)

Patented Kelman DGA 900 TAPTRANS is designed specifically for transformers with an On-Load Tap Changer (OLTC), which is recognised as one of the most vulnerable parts of the transformer and which accounts for a large portion of unplanned outages. It offers discrete multigas on-line DGA and moisture monitoring, separating the main and selector tanks from the diverter tank to avoid any risk of contamination. Utilizing photo-acoustic spectroscopy (PAS) measurement technology it provides laboratory challenging levels of precision and repeatability. Full 9 gas oil sampling and analysis can be performed as often as every hour on a single tank and up to once every three hours on all three connected oil tanks. The Kelman DGA 900 TAPTRANS has also new Rapid Mode for measuring 4 critical gases and moisture of the oil in about 30 minutes.


Innovative design of new Kelman DGA 900 TAPTRANS enables add-ons like electromechanical monitoring of OLTC and monitoring transformer bushings on one integrated platform.

Tap changer diverter oil
Tap changer selector oil
Transformer main tank oil

Kelman DGA 900 TAPTRANS monitoring transformer main tank, diverter and selector of On-Load Tap Changer