Seaward Checkbox 17 Plus - Manual (Page 3)

Insulation Resistance Check
The terminals marked 1 M are designed for testing insulation testers at a
maximum of 500V DC. Connect the insulation tester to the 1 M insulation
test terminals and compare the reading obtained to the calibrated value
recorded on the CheckBox 17 Plus Certificate of Test.
Connecting to Mains Supply
The following tests require the CheckBox 17 Plus to be connected to a
suitable 230V 50Hz supply. If the RCD indicator continuously flashes,
verify the supply earth and check for reversed L/N connections.
AC Voltage Measurement
The red terminals marked AC V provide a test voltage, which is current
limited to protect the user. The current limiting resistance may produce
some variation in readings between instrument types depending upon
their input impedance and methods of measurement.
Caution: Do not touch or insert non-insulated items into the voltage
test point. Care should be exercised when using this test facility to
avoid risk of electrical shock.
Connect the test instrument to the CheckBox 17 Plus test terminals and
compare the voltage being displayed to the value indicated on the Check
Box 17 Plus Certificate of Test.
Note: A variation in the supply voltage to the CheckBox 17 Plus will result
in a variation in test voltage.
Phase Earth Loop Linearity Test
Connect the phase earth loop tester to the 13A socket on the front panel of
the CheckBox 17 Plus. Perform a loop test and note test reading. Press
the momentary action switch to the LOOP +5R position, repeat the loop
test and make a note of the reading. Compare the difference in the two
readings to the value indicated on the CheckBox 17 Plus Certificate of
Test.
RCD Test
Check Box 17 Plus provides a calibration facility for both the current
setting and time measurement of an RCD tester.
Connect the CheckBox 17 Plus to a suitable 230V 50Hz supply. Plug the
RCD test unit under test into the 13A socket on the front panel of the
Check Box. - verify the RCD indicator flashes briefly.
a) Select the 30mA test position on the test instrument and apply the
test current. The CheckBox 17 Plus should operate in a time detailed
on the CheckBox 17 Plus Certificate of Test and the RCD indicator
should flash briefly on detection.
The circuit will automatically reset after 10 seconds and re-apply
power to the test socket.
b) Select test current of 25mA or less and repeat the test. The instrument
should now indicate a failure to trip or an operating time over range
symbol (depending on instrument type). The RCD indicator should not
illuminate.
c) Select test current over 30mA (not less than 35mA) and repeat the test.
The instrument display should once again display a failure to trip or
over range indication. The RCD indicator lamp should now illuminate
during the test period to indicate a current flow in excess of 30mA.
Provided that the correct light and test sequence are obtained in tests
(a) to (c) the instruments 30mA test position is within 30mA ± 5mA.