INSTALLATION
2-9
Check that the equipment has been installed in accordance with the instructions provided
(e.g. that ventilation is adequate, supply isolators are accessible, supply wiring is adequate and
properly routed).
The condition of the mains supply lead and supply connector(s).
Check that the mains supply switch isolates the instrument from the supply.
The correct rating and type of supply fuses.
Security and condition of covers and handles.
Check the supply indicator functions (if fitted).
Check the presence and condition of all warning labels and markings and supplied safety
information.
Check the wiring in re-wireable plugs and appliance connectors.
If any defect is noted this should be rectified before proceeding with the following
electrical tests.
2. Earth bonding tests
Earth bonding tests should be carried out using a 25 A (12 V maximum open circuit
voltage) DC source. Tests should be limited to a maximum duration of 5 seconds and have a
pass limit of 0.1
Ω
after allowing for the resistance of the supply lead. Exceeding the test
duration can cause damage to the equipment. The tests should be carried out between the supply
earth and exposed case metalwork, no attempt should be made to perform the tests on functional
earths (e.g. signal carrying connector shells or screen connections) as this will result in damage
to the equipment.
3. Insulation tests
A 500 V DC test should be applied between the protective earth connection and
combined live and neutral supply connections with the equipment supply switch in the ‘on’
position. It is advisable to make the live/neutral link on the appliance tester or its connector to
avoid the possibility of returning the equipment to the user with the live and neutral poles linked
with an ad-hoc strap. The test voltage should be applied for 5 seconds before taking the
measurement.
Aeroflex employs reinforced insulation in the construction of its products and hence a
minimum pass limit of 7 M
Ω
should be achieved during this test.
Where a DC power adapter is provided with the equipment, the adapter must pass the
7 M
Ω
test limit.
We do not recommend dielectric flash testing during routine safety tests. Most portable
appliance testers use AC for the dielectric strength test which can cause damage to the supply
input filter capacitors.
4. Rectification
It is recommended that the results of the above tests are recorded and checked during
each repeat test. Significant differences between the previous readings and measured values
should be investigated.
If any failure is detected during the above visual inspection or tests, the equipment should
be disabled and the fault should be rectified by an experienced Service Engineer who is familiar
with the hazards involved in carrying out such repairs.
Safety critical components should only be replaced with equivalent parts, using
techniques and procedures recommended by Aeroflex.
The above information is provided for guidance only. Aeroflex designs and constructs its
products in accordance with International Safety Standards such that in normal use they represent
