User guide

M4000 Insulation Analyzer User Guide
72A-1230 Rev. F 1-23
July 22, 2005
M4000 Operation
1. Both safety switches must be used in order to activate the test setup. One is
to be controlled by the M4000 operator and the other by a second test crew
member, designated the safety supervisor. (This person may be either the
Operator’s Assistant or the Safety Observer.)
2. The Test Set Operator or the Safety Observer must be able to have an
unobstructed view of the terminals of the equipment under test, any points
of entry into the immediate test area, and of the workers in the area.
M4000 Safety Features
The M4000 Insulation Analyzer is equipped with a ground-relay scheme,
which prevents test voltage from being applied until the following preliminary
conditions have been established:
1. A #6 copper conductor is provided by Doble for the purpose of grounding
the M4000 Insulation Analyzer. The heavy-duty #6 conductor should be
connected to the GROUND RECEPTACLE of the M4000 Insulation
Analyzer at one end and to the station grounding system at the other end.
This should be the first step in setting up the M4000.
2. After the M4000 Insulation Analyzer is properly grounded, the remaining
test leads and the HV Test Cable are plugged into their receptacles. Do not
connect test leads to the apparatus terminals until after the leads are
connected to the M4000.
3. The power cord should be plugged into a 120V ac or 240V and grounded
receptacle. This should be the last step in setting up the M4000.
4. Two separate grounds are required to pick up the ground relay and operate
the M4000: one as described in item 1 above, and the other through the
third wire of the 120/240 volt supply cord. Care should be taken to ensure
that there is no direct contact between the two grounds. Short circuiting
the two grounds together may create a hazardous condition if the ground
connection is inadvertently interrupted.
5. The HV Test Cable used with the M4000 is a double-shielded cable in
which the high voltage is exposed only at the outboard pothead tip. The
HV Test Cable should not be handled while it is energized. If a flashover
occurs while testing, transient voltages higher than 10 kV can appear on
the cable and puncture the insulating jacket of the cable, creating a hazard
to personnel holding the cable. The cable may be suspended or tied off in
such a way as to avoid handling.