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Standard DSP-OHMNI Components:
- DDR2 voltage alarm unit
- OHMNI-PM or OHMNI-PM-RM resistor
- (DSP-DSYS)
- DSP-TDM (Touch Display Monitor)
- DSP-DPS Power Supply Module
- DSP-DSM Sytem Module
- DSP-DCM Communication Module
DSP-OHMNI Optional Modules (35 mm Din Rail):
- DSP-DRM Resistor Monitoring
- DSP-DFM Feeder Module
- DSP-ADM Arc Detection Module
- DSP-CA Cable Adaptor
- DSP-CAS Cable Adaptor with on/off switch
Standard DSP-OHMNI components
The DDR2 is a voltage alarm unit used for line-to-ground-voltage measurements of three phase power systems. The
DDR2 alarm unit may be used on wye connected resistance grounded systems or delta connected systems using an
artificial neutral with a neutral grounding resistor.
The OHMNI-PM is a neutral grounding resistor used to limit the ground fault current to a safe level (typically 5A or
10A) for an indefinite time. The resistor is available for 480V & 600V systems and can be equipped with optional
resistance monitoring components (sensing resistor & ZSCS) becoming an OHMNI-PM-RM. Both models includes
an integrated pulsing module to modulate the current in the fault circuit which can be detected by a portable clamp-on
current probe (TS-SENSOR) connected to an ordinary ammeter (DMM) meter.
The DSP-TDM is a panel-mounted display designed for flush mounting in a door. The DSP-TDM display indicates
faulted phase, total system leakage current, feeder branch current level and provides other information such as prior-
ity settings and resistor setting etc. It is used to set-up the system and provides manual control of the pulse location
system. The DSP-DM also provides MODBUS RTU communications through a RS-485 network and MODBUS TCP
communications through a Ethernet network to external information systems. The module includes a real-time clock
to signal the event time and date of each event captured (up to 1000 events). Events captured are loss of DDR-2
phase(s), bus fault, feeder fault, feeder trip and NGR fault for both trip-on-first-fault, and trip-on-second- fault setups.
The DSP-TDM date stamps the events according to the time and date set up on the system set-up.
The DSP-DPS is a 35mm Din Rail mountable power supply module used to p5V, +12V and -12V regulated
power to all of the modules and also provides 10A, 240 VAC resistive Form C alarm relay contacts to operate a horn
or other means of alarm to alert the operator . The DSP-DPS operates on a wide range of AC input voltage supplies
from 100V to 240V AC without selection of any jumpers or switches and can also operate on a wide range of DC input
voltage supplies from 125V to 250V DC.
The DSP-DSM is a 35mm Din Rail mountable system module used to monitor the systems line-to-ground voltages
through the DDR2 voltage alarm unit. It determines if there is voltage unbalance in the system and the level of ground
fault current in the grounding resistor by measuring the voltage displacement of the neutral from ground, without any
connection to the neutral grounding resistor. It also signals phase indication to the DSP-TDM Display.
Optional DSP-OHMNI modules (35mm Din Rail mountable)
The DSP-DRM is the resistor monitoring module used to monitor the integrity of the neutral grounding resistor (NGR)
for change of resistance and/or open circuit condition. This module must be installed following the system module
(DSP-DSM) in the 35mm Din Rail line-up of the DSP-OHMNI system. The DSP-DRM uses external I-Gard zero se-
quence current sensors and a NGRS sensing resistor which provide voltage and current measurements of the neutral
grounding resistor to the (DSP-DSM). The DSP-DRM uses the same alarm system as the rest of the DSP-OHMNI
system.
The DSP-DFM is the feeder module which can be included in the DSP system to measure the fault current level in the
branch circuits that are protected. This module uses standard I-Gard zero sequence current sensors Type TxA or Rx-
yA. It is equipped with a Form C 10A output relay that can be used for breaker control. The DSP-DFM detects two fault
levels. Firstly, it detects the single fault, which creates a system alarm condition, and secondly through a priority level
system, it provides breaker
Summary of Contents for DSP-OHMNI
Page 1: ...C EG30EM Instruction Manual V2 June 2020 DSP OHMNI ...
Page 11: ...9 Figure 1b DSP DCM Wiring Figure 1c System Module DSP DSM Wiring ...
Page 12: ...10 Figure 1d Power Supply DSP DPS Wiring Figure 2 Preferred Feeder Module DSP DFM Wiring ...
Page 45: ...43 Figure 41 DSP DPS System Module Connection ...
Page 46: ...44 Figure 43 DSP DLM Logging Module Connections Figure 44 DSP TDM Display Module Connections ...
Page 47: ...45 Figure 45 Typical DSP DRM Installation Connections ...
Page 50: ...www i gard com Phone 905 673 1553 Toll Free 1 888 737 4787 Fax 905 673 8472 sales i gard com ...