32
Figure 33: NGR Fault
If a DSP-DRM is not connected, the following message will be reported:
Pressing ENTER will terminate the set-up and self-test and the HOME screen will be returned. If the DSP is left in the
set-up mode, it will not gather information on the system, however feeder protection will still be effective. If the DSP is
left accidentally in the set-up mode it will reset automatically after a period of approximately 1 hour.
Maintenance and Testing
Due to the solid state design and the use of sealed components, it is not necessary to service the DSP other than oc-
casionally dusting with a damp cloth or vacuum cleaner during regular switchboard maintenance. To test the DSP, it will
normally be sufficient to use the SELF-TEST procedure. Testing the system in the field involves placing a ground fault
on one of the lines. This should only be performed with the permission of the owner and by qualified individuals using
proper techniques, to ensure safety to plant, equipment and personnel.
DANGER
Hazard of Electrical Shock, Burn or Explosion!
All installation, servicing and testing referred to in this manual must be performed by qualified
personnel. All power should be disconnected prior to removing covers or enclosures and where live conductors may
otherwise be exposed.
Failure to observe these precautions may result in death or severe personal injury and damage to equipment. Before
placing an intentional ground fault on the power system, check that a fault does not already exist. Any test ground fault
equipment must be rated for full system voltage and be fused for protection.
A complete test of the system can be accomplished with the connection of a resistive fault between one of the three
lines and ground at a location downstream of one of the feeder current sensors. This simple test will identify the integ-
rity of sensor, feeder module circuits, connections, communications, system module operation, DDR2 resistor OHM-
NI-PM resistor and pulsing without causing a trip to occur on any of the breakers. The only thing it will not test is the
priority of the double-fault trip process. For this, two such resistors would be required, with resistor value low enough
to provide more than the 100A trip current required for the selective second ground fault tripping.
DANGER
Never use a piece of wire to create a test fault. It is possible that the protection may not be operational due to mis-
wiring or other problems and cannot clear the fault current resulting in a serious arcing situation which may severely
damage the equipment and cause injury or death.
Figure 34: DSP-DRM Not Connected
The health of the NGR is monitored. If the NGR becomes open or shorted this is an NGR FAULT. Such a fault is an-
nunciated as shown in Figure 33 below.
Содержание DSP-OHMNI
Страница 1: ...C EG30EM Instruction Manual V2 June 2020 DSP OHMNI ...
Страница 11: ...9 Figure 1b DSP DCM Wiring Figure 1c System Module DSP DSM Wiring ...
Страница 12: ...10 Figure 1d Power Supply DSP DPS Wiring Figure 2 Preferred Feeder Module DSP DFM Wiring ...
Страница 45: ...43 Figure 41 DSP DPS System Module Connection ...
Страница 46: ...44 Figure 43 DSP DLM Logging Module Connections Figure 44 DSP TDM Display Module Connections ...
Страница 47: ...45 Figure 45 Typical DSP DRM Installation Connections ...
Страница 50: ...www i gard com Phone 905 673 1553 Toll Free 1 888 737 4787 Fax 905 673 8472 sales i gard com ...