Cut Sheet

Descriptive bulletin | FT Flexitest family 13
Test plugs used in conjunction with Flexitest switches enable
easy measurement, calibration, verification and maintenance of
relays, meters and instruments.
5.1. In-Service Series Test Plug
The “In-Service” Series Test Plug with a maximum of 10 posi-
tions is designed to match the pole configurations of specific
styles of FT Flexitest devices (either FT-1, FT-1F, FT-1X switches
or FT case relays).
This test plug is typically used to connect devices measuring the
currents and voltages being applied to the switchboard relays,
meters and instruments without interrupting or short-circuiting
the circuit. Only current test switches with a current test jack
must be opened before inserting the Series test plug. Connec-
tions to the test plug must be made before inserting the test
plug into a Flexitest switch or relay.
Not every switch or relay pole configuration is suitable to accept
an In-Service Series Test Plug. For available styles, see table
1, FT-1 switch selection guide 1VAC397062-SG. You may also
refer to your ABB representative or ABB FT-1 configurator at
www.ft1switch.com.
WARNING
When using an In-Service Series Test Plug for current measure-
ments, connections from the test plug to the measuring instru-
ments must be made before inserting the test plug in place.
5.2. Individual Current Circuit Test Plug
This plug consists of two conducting strips separated by an
insulating strip. The ammeter is connected to these strips by
terminal screws and leads carried out through holes in the back
of the insulated handle. (See figures 2 and 4 on page 14).
The standard test plug inserts into the current test jack with the
red part of the handle facing up allowing the alignment nipple
and tab to guide the connector into the test jack.
5.3. SafePlug with open CT protection
The SafePlug is an individual current circuit test plug with open
current transformer (CT) protection provides a safe, simple,
fast, and reliable method to test and service installed equipment
while reducing risks due to operator error, incorrect equipment
settings, or deviation from correct test procedures.Its design
prevents shock hazards, outages, and erroneous meter read-
ings all associated with open CTs.
If a CT opens during operation, the test plug shorts the CT to
protect the operator, typically within 100 microseconds or less
(6/1000th of a cycle). At the same time a red LED provides
visual indication of the fault.
5. Test plugs
Figure 6. SafePlug with open CT protection
! Warning
Complete CT secondary circuit connections from the Individu-
al Current Circuit Test Plug to the measuring instrument must
be made before inserting the Test Plug in place.