Littelfuse CT SelecTiOn Guide User Manual
Ct selection guide, Accessories, Current transformers (cts)
Accessories
© May 2012 Littelfuse Protection Relays & Controls
www.littelfuse.com/relayct
current Transformers (cTs)
cT SelecTiOn Guide
*Phase CTs should be selected with a primary rating of 100-300% of rated current to maintain specified accuracy. CTs with a 1-A or 5-A secondary are accepted.
†Trip levels are model specific, see ordering information..
‡Select a CT with a primary rating approximately equal to the system’s rated current. CTs with 5-A secondary current are accepted.
PrOducT
GrOund-faulT cT
GrOund-faulT TriP leVel
(or insulation level)
SE-601
No CTs required
1-20 mA
PGR-3100
No CTs required
Indication only
PGR-3200
No CTs required
Warnings at 30 kΩ & 50 kΩ,
Alarm at 10 kΩ
SE-502
No CTs required
5 ± 0.9 mA
SE-701/SE-703
CT-200 Series
10-198 A
EFCT Series
50 mA-4.95 A
SE-CS30 Series
300 mA-29.7 A
SE-704
SE-CS30 Series
10 mA-5 A
EL731
EFCT Series
30-5,000 mA AC and DC
SE-105/SE-107
CT200 Series
0.5-4 A
SE-134C/SE-135
SE-CS10 Series
0.5-12.5 A
SE-145
SE-CS10 Series
0.5-12.5 A
SE-CS40 Series
2.0-50 A
SE-330
CT200 Series
12-200 A
EFCT Series
100 mA-5 A
SE-CS30 Series
600 mA-30 A
SE-325
CT200 Series
0.5-4 A
PGR-6150
No phase CTs required <25 A,
Optional SE-CS30 Series Ground-Fault CT
0.4-150 A
MPU-32*
CT200 Series
10-200 A
EFCT Series
50 mA-5 A
SE-CS30 Series
300 mA-30 A
MPS*
CT200
10-200 A
EFCT Series (5-A Primary)
50 mA-5 A
SE-CS30 Series (30-A Primary)
300 mA-30 A
MPU-32-X69X-PMA16
Existing CTs can be used or same as MPU-32.
MPS-469X-PMA24
Existing CTs can be used or same as MPS.
PGR-6800
No CTs required <91 A
N/A
†
FPU-32*
CT200 Series
10-200 A
EFCT Series
50 mA-5 A
SE-CS30 Series
300 mA-30 A
FPS*
CT200
10-200 A
EFCT Series (5-A Primary)
50 mA-5 A
SE-CS30 Series (30-A Primary)
300 mA-30 A
AF1000
‡
CTs are optional
N/A
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