
Magnelab Mini AC Current Transformer (CT) Connection Instructions
For use with HOBO®H22, U30, and RX3000 Series Data Loggers
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14255-C MAN-MINI-CT-x
Applies to these Magnelab CTs
Onset Part No. Rated Current Output Magnelab Part No.
T-MAG-0400-05 5 Amps 0-333mV AC representing 0 to 5 Amps AC SCT-0400-005
T-MAG-0400-20 20 Amps 0-333mV AC representing 0 to 20 Amps AC SCT-0400-020
T-MAG-0400-50 50 Amps 0-333mV AC representing 0 to 50 Amps AC SCT-0400-050
T-MAG-0400-75 75 Amps 0-333mV AC representing 0 to 75 Amps AC SCT-0400-075
DANGER!—HIGH VOLTAGE HAZARD
Installing CTs in an energized electrical enclosure or on any energized conductor can result in severe injury or death. These CTs
are for installation by qualified personnel only. To avoid electrical shock, do not perform any installation or servicing of these CTs
unless you are qualified to do so. Disconnect and lock-out all power sources during installation and servicing.
This document provides instructions on connecting the Magnelab CTs listed above to the
FlexSmart™TRMS Module used with either HOBO H22, U30, or RX3000 series data
loggers. It also lists configuration values used by HOBOware®software to configure the
logger for each CT.
Required
•Selected Magnelab CT
•HOBO H22, U30, or RX3000 series data logger
•FlexSmart TRMS Module, Onset Part No: S-FS-TRMSA (for H22 series only) or
S-FS-TRMSA-D (for H22, U30, or RX3000 series)
•HOBOware software, version 2.2.1 or higher (2.4.0 or higher for U30 series)
•HOBOlink (for RX3000 series)
Connecting the CT to the FlexSmart TRMS Module
HOBO H22 or U30 Series Data Logger
(H22-001 shown)
S-FS-TRMSA / S-FS-TRMSA-D*
FlexSmart TRMS Module T-MAG-0400-xx
Current Transformer
S1~
S1~
S2~
S2~
S-FS-TRMSA (or S-FS-TRMSA-D)
FlexSmart TRMS Module
Terminal Block
Wiring Diagram for Single CT
Black
White
See below for wire
capture procedure
From CT
S1~
S1~
S2~
S2~
S-FS-TRMSA (or S-FS-TRMSA-D)
FlexSmart TRMS Module
Terminal Block
Wiring Diagram for Two CTs
Black
White From CT
Black
White From CT
LOAD
LINE
3. Snap CT closed.
1. Open CT. Source Face
2. Place CT around the
individual wire carrying the
phase to be monitored.
*The S-FS-TRMSA-D has a modular connector for
connecting to a Smart Sensor port and thus is compatible
with both H22 and U30 series data loggers. The
S-FS-TRMSA is compatible with the H22 series only.
S-FS-TRMSA-D*
Magnelab Mini AC
Current Transformer
HOBO H22, U30, or RX3000 Series Data
Logger (H22-001 shown)
*The S-FS-TRMSA-D has a modular connector for connecting
to a smart sensor port and thus is compatible with H22, U20,
and RX3000 series loggers. The S-FS-TRMSA is compatible
with the H22 series only.