Using the EDS190P within a permanently installed EDS system

The EDS190P can also be used in a permanently installed EDS system (EDS460/490 resp. EDS461/ 491). In extended IT systems with a number of sub-distributions, often only the main distributions are monitored by a permanently installed EDS system. When the main distribution where the insu- lation fault exists is recognised, the search will be continued from that point using the EDS190P. For this purpose, the EDS190P uses the test current pulse of the permanently installed EDS system (IRDH575, PGH47...). The PGH18... is not required for this application. The scope of delivery of the EDS3090 and EDS3091 systems does not include a PGH18.... Insulation fault location can only be car- ried out in energised IT systems. Also observe the operating instructions of the permanently installed EDS system.

Example: The insulation monitoring device has signalled an insulation fault below its response value and has started the permanently installed EDS system. The main distribution affected by an insula- tion fault has been recognised. Continue insulation fault location as follows:

1. Set the EDS system mode to permanent insulation fault location: – IRDH575: Set "EDS on"

– PGH471: Press the "Start/Stop" button

2. Connect a suitable measuring clamp to the EDS190P. 3. Switch on the EDS190P by pressing the On/Off button. 4. Make the following settings:

–Select function IΔs (EDS mode) with the button –Set the maximum sensitivity:

50 mA for main circuits for EDS460/490 for the measuring clamps PSA3020, PSA3052, PSA3165 and the measuring current transformers W/WR…, WS…

5 mA for control circuits for EDS461/491 for the measuring clamps PSA3320, PSA3352 and measuring current transformers W…8000, WS…8000

– Select the measuring clamp or the measuring current transformer to be used with the but- ton.

– Set the supply system of the system to be checked in the menu 2.3 (setting IΔs).

– Select yes in menu 2.3 (setting IΔs) if frequency converters are connected to the sub-distri- butions to be tested.

5. When using measuring clamps, please note:

– Do not connect the core of the measuring clamp to system voltages above the nominal insulation voltage.

For operating currents < 10 A, it is also possible to enclose one conductor only. For currents > 10 A, this may produce the effect that the measuring clamp can no longer be opened. This danger is particularly present in DC systems. If this behav- iour occurs, under no circumstances use force, since this would destroy the meas- uring clamp. Instead, you must disconnect the respective system. After this has been done, the measuring clamp can be opened without the application of force.

Operation

– Keep the contact surfaces of the measuring clamp clean.

– The measuring clamp should not be used in the immediate vicinity of devices which gener- ate magnetic fields, such as transformers or throttles, nor in the vicinity of adjacent conduc- tors with high operating currents.

– Do not disconnect the measuring clamp from the EDS190P when live conductors are enclosed by the measuring clamp. Otherwise the measuring clamp may be destroyed! – Inside the measuring clamp, you should aim for the maximum possible symmetry of the

conductors. Due to excessively high load current, the measuring clamp can reach a satura- tion state that may cause an alarm message IΔn >10A.

– Keep the measuring clamp steady during the measurement!

– Make sure that you do not exert any pressure on the measuring clamp arms.

– Enclose the green-yellow conductor with the measuring clamp between the IRDH575 resp. PGH47... and earth. When the EDS190P does not react, the insulation fault is too high and cannot be found. Recognised test current pulses are indicated by the symbol . 6. Start insulation fault location in the sub-distribution of the IT system recognised to be faulty.

Enclose all system conductors, but not the PE conductor, with the measuring clamp. For each measurement, wait for one test cycle (approx. 30 seconds). An alarm message on the EDS190P display signals an insulation fault downstream of the measuring clamp. It is recommended to carry out fault location with the buzzer activated.

The EDS190P can display the following messages during insulation fault location: – No CT connected:

Measuring clamp or measuring current transformer not connected or defective. – Fault:

Measuring clamp is not held steady. A residual current flows through the measuring clamp affecting the EDS measurement.

A magnetic field exist in the vicinity of the measuring clamp which disturbs the EDS meas- urement.

In these cases, the insulation fault cannot be located in the respective sub-distributions resp. at the location of measurement.

– Idn >10A / >1A:

A residual current of > 10 A resp. >1A flows through the measuring clamp. In this case, the insulation fault cannot be located in the respective sub-distribution. Residual currents of this size occurring in an IT system can be caused by high system leakage capacitances or by multiple insulation faults. Therefore, it is possible that this alarm message also signals an insulation fault in this sub-distribution.

– >>>>:

Measurement is running, this display shows the progress of the measurement. This process will be completed after approximately 30 seconds.

– Next measurement:

No insulation fault found in this sub-distribution. The measuring clamp or the measuring current transformer can be moved to the next sub-distribution.

– Alarm ...mA:

An insulation fault has been detected in this sub-distribution. Measurement should be con- tinued along this conductor.

7. Measure along the conductor with the EDS190P until the fault is found. Penetrate radially into the sub-distributions as you do this. The fault location is found when the test current through the measuring clamp generated by the IRDH575 resp. PGH47... at least exceeds the preset response value of the EDS190P.

Operation