GE Kelman DGA 900 Plus - 9 CARD OPTION #4: BUSHING & PD MONITOR; 9.1 Installation Layout

MA-041 – DGA 900 Plus - Installation & Commissioning Manual - Rev 1.1 4-Mar-22 Page 33 of 99
9 CARD OPTION #4: BUSHING & PD MONITOR
The Bushing & PD card:
▪ measures the condition of transformer bushings (through changes in Capacitance
and Power Factor) for one or two sets of three bushings in a single three-phase
transformer, or three single-phase transformers.
▪ detects any Partial Discharges (PD) activity in the transformer main tank (measured
as high frequency pulses).
This option uses the following adaptors and sensors:
▪ Three Bushing Adaptors (Primary input) connected to the tapping point of the
bushings being monitored.
▪ (Optional) Three Bushing Adaptors (Secondary input) connected to the tapping point
of a second set of bushings being monitored.
▪ Three High Frequency Current Transformer (HFCT) sensors at the transformer(s)
neutral (if applicable).
▪ Three magnetically-mounted temperature sensors (MMTS) mounted on the
transformer tank(s) to measure the transformer top oil temperature (if applicable).
All commissioning details are found in Section 10.4. Refer to the ‘MA-040 – DGA 900 Plus
– Operator Guide’ for all other operational details relating to the software interface for
configuration, bushing settings, data readings and alarms.
Note: A complete list of parts and tools required for the Bushing & PD monitor
installation is given in Appendix A.
9.1 Installation Layout
WARNING: Do not attempt to install the product unless the transformer is
de-energised and switched off.
WARNING: Ensure that the HV and LV bushings are grounded before
installation of the product.
The product should not be mounted where it may interfere with the
transformer cooling system or maintenance activities.
Contact GE Technical Support before mounting the product directly on the
transformer.
See Section 7 of the standard MA-024 DGA 900 Installation Manual for further guidance
on mounting and location advice.
Figure 9-1 illustrates the general installation layout of a DGA 900 Plus with the required
connections for a single transformer.