8
Operating Instructions
General operation
The MIT515, MIT525, MIT1025, MIT1525 Insulation resistance
testers (IRTs) are primarily controlled by two rotary switches
and a TEST button used to start and stop a test (see section
entitled, ‘Instrument Control and Indicators’). The central rotary
switch includes an ‘OFF’ position; the instrument switches on
by rotating the switch either clockwise or anticlockwise from
this position. A range of test voltages for insulation resistance
tests up to 5 kV for MIT515/MIT525,10 kV for MIT1025 and 15
kV for MIT1525 are available, including a user selectable
voltage range which can be set between 40V or 100 V and
5000 V, 10000 V or 15000 V depending on model. The
‘lockable’ test voltage range can be adjusted in the settings
function.
The settings function is indicated by a spanner symbol and
facilitates lock voltage, low resistance alarm, temperature,
time/date adjustment. A light blue coloured section of the
rotary switch denotes memory functions; open records,
download via USB and delete records. A dedicated save
button is provided on the MIT525, MIT1025 and MIT1525
models and all models have a backlight button.
A second rotary switch controls the insulation test mode
providing for the following tests:
•
All models have basic insulation resistance IR, timed
insulation resistance IR(t), Dielectric Absorption Ratio
(DAR) and Polarisation Index (PI) tests.
•
MIT525, MIT1025, MIT1525 have additional tests;
Dielectric Discharge (DD), Step Voltage (SV) and ramp
test.
A cluster of directional buttons and an OK button are used in
settings and memory functions. The up/down arrows also
enable the test voltage to be adjusted during a test. Prior to
the start of an IR or IR(t) test, holding down the left arrow
button with a voltage level selected on the central rotary switch
will activate burn mode. Burn mode is deactivated if the
voltage range or mode is changed or by pressing the right
arrow/breakdown button.
Instrument controls are simple to operate. The central rotary
switch incorporates the OFF position. The left hand rotary
switch selects insulation test type (test mode switch). The
TEST button starts and stops a test.
Four arrow buttons and OK facilitate adjustment and selection
of settings, voltages and modes. Breakdown/burn modes are
set using the left and right arrow buttons. Backlight and save
functions are dedicated buttons. All models have backlight and
the MIT525, MIT1025 and MIT1525 have the Save button.
