Tettex MIDAS 2881, Operating Instructions Manual

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Safety 7
Non-test related persons who are working in proximity to the area where testing is performed must be
informed. Consistent visual and verbal signals should be agreed and followed.
Perform only one job at a time on any equipment. The situation in which two crews are doing different
tasks with the same equipment at the same time is an open invitation for confusion, trouble, and
danger to the personnel.
People with heart pacemakers should not be in the vicinity of this system during operation.
3.3 Safety Features
Beside an Emergency Stop switch the MIDAS is equipped with an external Safety Switch (spring-
release type or a 'dead man' type). The Safety Switch should be controlled by the second test crew
member (safety observer). Without the Safety Switch the instrument can not be activated.
Prior to making the first measurements, the Safety Switch operator should verify the correct
operations of the switch.
It is recommended that the Safety Switch be the last switch closed. It must remain open until all
personnel are safely in the clear. If unauthorized personnel should enter the area, or if some other
undesirable situation should develop, the Safety Switch operator should release the switch
immediately, and then notify the MIDAS operator.
The Safety Switch should be used at all times. Never short circuit it and do not use fixed mechanical
locking devices for depressing the switch button. The switch button must be manually operated at all
times.
For visual warning of high voltage presence a warning lamp bar is located on the top rear side of the
instrument. Optional a strobe light is delivered which can be mounted on the device under test.
The MIDAS is equipped with a HV GND connection surveillance. The high voltage can only be
switched on when the earth circuit is properly connected. The instrument indicate the status
“Grounded” or “Open” by LED and by software.
A separate green/yellow earth cable is provided for the purpose of safety grounding the instrument.
The earth cable should be connected to the Earthing Screw on the back of the MIDAS at one end and
to the station grounding system at the other end.
The green / yellow safety ground cable should be the FIRST lead to be connected to the set.
3.4 Safety Precautions
All tests must be performed with the device under test completely de-energized and isolated from its
power systems. The equipment, its tank or housing must be disconnected from all buses and properly
earthed, so that all induced voltages or trapped charges are neutralized. Only when the measurement
procedure is actually being performed the grounds should be temporarily removed.
The MIDAS must be solidly earthed with the same ground as the device under test. When the MIDAS
is permanently housed in a vehicle, the MIDAS ground should be bounded to the vehicle chassis,
which in turn is grounded.
Exposed terminals of equipment should not normally be allowed to 'float'. They should be grounded
directly or through the low voltage leads (INPUT V) of the MIDAS, unless otherwise specified.
Testing of high voltage equipment involves energizing the equipment through the MIDAS. This can
produce dangerous levels of voltage and current. Care must be taken to avoid contact with the
equipment being tested, its associated bushings and conductors, and with the MIDAS cables.
Especially the high voltage test cable should not be held during energization of the MIDAS. Flashover
of the test specimen or the MIDAS can generate transient voltages of sufficient magnitude to puncture
the insulating jacket of the high voltage test cable.