Tettex MIDAS 2881, Руководство по эксплуатации

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8 Safety
8
It is strongly recommended that the test crew make a visual check to ensure that the equipment
terminals are isolated from the power system. If there is real possibility that the device under test fails
precautions such as barriers or entrance restrictions must be taken against harm in the event of
violent failure.
Proper clearance between the test equipment and the device under test must be ensured during the
presence of high voltage. Barriers and safety tapes can be established around the test area to prevent
unintentional entry into the live area. It must also be guaranteed that extraneous objects like ladders,
buckets, etc. can not enter the test area.
After the MIDAS is properly grounded, the remaining test leads and the High Voltage Test Cable are
plugged into their receptacles.
Do not connect test leads to the equipment terminals until after
the leads are connected to the MIDAS.
The proper procedures for connecting the MIDAS leads to the device under test is described in detail
in chapter "Accessories and Options" The safety observer should supervise this procedure at all
times.
The MIDAS operates from a single-phase power source. It has a three wire power cord and requires
a two-pole, three terminal, live, neutral and ground type connector. Do not bypass the grounding
connection. Any interruption of the grounding connection can create electric shock hazard.
The
power input connection should be the last step in setting up the instrument.
After the tests are completed, all test leads should be disconnected first from the device under
test and earthed before they are disconnected from the instrument.
The green / yellow safety ground cable should be the LAST lead to be disconnected from the
set.
Do not disconnect the voltage cables from unless the MIDAS Voltage is set to HV OFF, and the
Safety Switch is released. Attempts to disconnect leads while the MIDAS is energized may
result in a serious and possibly lethal electrical shock.
3.5 Summary
Note: Many accidents that happen around high voltage equipment involve personnel who are familiar,
and perhaps too familiar, with high voltage equipment. Staying alert and ever watchful requires
constant training and awareness of the inherent hazards. The greatest hazard is the possibility of
getting on a live circuit. To avoid this requires constant vigilance - for oneself and for one's fellow
workers.
In addition to the obvious dangers, personnel should be alert to recognize subtle dangers as well. For
example, during transformer excitation-current tests, the floating terminals may have significant
voltages induced in them by simple transformer action. Therefore,
all terminals of a device under
test, unless grounded, should be considered to be live while the test is in progress.
When potential transformers or any transformers are interconnected, voltage can be back-fed through
the secondary windings to produce high voltage on the primary although the primary is seemingly
isolated from the power system. This entail a second important rule -
all terminals of a device under
test should be completely isolated.
Finally it should be noted that the MIDAS is relatively heavy. We recommend that at least two people
are used to slide the MIDAS and three to lift it. Special care must be taken in lifting or sliding the
Instrument into or from a vehicle so as not to incur bodily injury.
Remember - Safety, FIRST, LAST, ALWAYS !