PR Series: 
Protective current transformers are required to operate over a range of current many times the circuit rating and is frequently subjected to conditions greatly exceeding those which it would be subjected to as a measuring current transformer. When a current transformer is used to energize a protective relay, it must maintain its characteristic ratio up to some multiple of its rated current. This multiple, may be 5, 10, 20 or some even higher value and is know as the "Accuracy Limit Factor"(ALF). Therefore, the selection of Protective Current Transformers in relation to accuracy class and ALF require a close examination of relay characteristic and circuit conditions which includes the relay burden and the pilot wire lead burden. 

Dimensions (mm):

Spec.	60/5A	100/5A	150/5A	200/5A	250/5A	300/5A	400/5A	500/5A	600/5A
OD	100	100	100	100	96	96	96	100	100
ID	34	34	34	34	34	34	34	60	65
HT	148	98	68	58	68	68	68	48	58

CI: 50P5 15VA

Spec.	100 /5A	150 /5A	200 /5A	250 /5A	300 /5A	400 /5A	500 /5A	600 /5A	800 /5A	1000 /5A	1200 /5A	1600 /5A	2000 /5A	2500 /5A	3000 /5A	3500 /5A	4000 /5A	5000 /5A
OD	100	100	100	96	96	96	102	110	120	120	123	123	123	178	178	182	182	184
ID	34	34	34	45	45	45	62	68	62	85	82	82	125	125	125	120	120	118
HT	180	130	110	110	110	90	110	88	22	68	60	68	40	40	40	35	35	38

CI: 10P10

Spec.	100 /5A	150 /5A	200 /5A	300 /5A	400 /5A	500 /5A	600 /5A	800 /5A	1000 /5A	1200 /5A	1600 /5A	2000 /5A	2500 /5A	3000 /5A
OD	100	100	100	96	96	102	110	120	120	123	123	178	178	178
ID	34	34	34	45	60	60	68	62	85	82	82	125	125	125
HT	168	108	88	108	108	88	88	22	58	60	50	38	38	38