500, 1500, 1000, and 1000:5 from X1 to 2, and 2 to 3 and so on. Other ratios are derivable from those. ANSI/NEMA/IEEE assumed, don't know if IEC is the same.
Interesting. I never looked at how turns ratios add up on CTs. I went to a document I found in my old files and found the datat below. With this info, you can figure the turns ratio between any two terminals. e.g., on a 600:5, the ratio for tapping beween X2 and X4 is (50+250):5 or 300:5.
600:5
X1:X2 20 turns x 5 = 100:5
X2:X3 10 turns x 5 = 50:5
X3:X4 50 turns x 5 = 250:5
X4:X5 40 turns x 5 = 200:5
1200:5
X1:X2 40 turns x 5 = 200:5
X2:X3 20 turns x 5 = 100:5
X3:X4 100 turns x 5 = 500:5
X4:X5 80 turns x 5 = 400:5
2000:5
X1:X2 80 turns x 5 = 400:5
X2:X3 160 turns x 5 = 800:5
X3:X4 60 turns x 5 = 300:5
X4:X5 100 turns x 5 = 500:5
3000:5
X1:X2 200 turns x 5 = 1000:5
X2:X3 240 turns x 5 = 1200:5
X3:X4 60 turns x 5 = 300:5
X4:X5 100 turns x 5 = 500:5
4000:5
X1:X2 100 turns x 5 = 500:5
X2:X3 300 turns x 5 = 1500:5
X3:X4 200 turns x 5 = 1000:5
X4:X5 200 turns x 5 = 1000:5
5000:
X1:X2 300 turns x 5 = 1500:5
X2:X3 100 turns x 5 = 500:5
X3:X4 400 turns x 5 = 2000:5
X4:X5 200 turns x 5 = 1000:5
I'll have to disagree with stevenal. On circuit breakers and transformers I've seen in the USA, the polarity marks of bushing CTs have been away from the device. I don't know if there is a standard for this.