I-GARD SENTINEL HIGH RESISTANCE GROUNDING CHOSEN BY CELANESE

Celanese Nanjing Integrated Chemical Complex, wholly owned by Celanese, is located at the Nanjing Chemical Industrial Park, north of the Yangtze River. The Nanjing Complex is Celanese's largest integrated complex in the world. Construction of the complex began in 2004. In September 2007, Celanese officially announced the opening of the complex.

High standards were held during the construction of the Nanjing Integrated Complex. Taking into account the high frequency of phase to ground fault in the rotating equipment, power continuity is a major concern in the design. In light of this, High Resistance Grounded systems were chosen to provide continuous power supply. When the system is high resistance grounded, the ground fault current is limited to such a low value that the on the occurrence of a single phase to ground fault.

I-GARD Sentinel High Resistance Grounding systems (Sentinel) were chosen for this project after market research and comparison. Sentinel is a compact turn-key product. We installed Sentinel HRG systems for all five production units. There are 13 sets of Sentinel HRG installed at the Nanjing plant. The system voltage is 380 VAC.

One unique feature of Sentinel is that it offers a selective second ground fault trip. This feature provides priority to different feeders so that power continuity of the more important feeder is maximized.
Another benefit that Sentinel offers is fast ground fault location. On the occurrence of a single ground fault, Sentinel gives an alarm and pulsing signal. With a flexible zero sequence current sensor, we can locate the ground fault very easily.

After two and a half years operation, we believe that the investment in the HRG systems pays back. Otherwise, the cost of power loss and production loss would have far outweighed the investment in HRG systems. 

“We think the Sentinel High Resistance Grounding system is a good match for our application and benefits us in providing power and production continuity. We are very satisfied with the many features of the I-GARD HRG systems, and look forward to even greater simplification of the fault location process.”