Experimental Investigations of the Seismic Performance of a Base-Isolated Uninterruptible Power Supply (UPS) through Shaking Table Tests

Table 4

Fundamental frequencies at different locations of the UPS test specimens.

Specimens		Scaling factor (%)	Fundamental frequencies (Hz)
			UPS top		Control switch		Cooling system		Transformer
			X-dir.	Y-dir.	X-dir.	Y-dir.	X-dir.	Y-dir.	X-dir.	Y-dir.
Series A	1A-3A	Initial	9.08	17.38	9.05	13.83	9.08	17.40	8.98	16.60
	6A-8A	100	8.33	18.25	8.30	13.48	8.33	17.63	8.18	17.18
	10A-12A	200	8.10	16.28	8.05	13.25	8.08	16.25	7.93	16.23
Series B	1B-3B	Initial	4.21	3.41	4.15	3.41	4.24	3.41	4.13	3.39
	6B-8B	100	4.00	3.38	3.95	3.38	4.00	3.38	3.94	3.37
	10B-12B	200	3.53	3.12	3.61	3.11	3.53	3.12	3.41	3.11