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Communications wiring may be 2-wire or 4-wire but must use shielded cable with low capacitance. Wire lengths up to 

2000 meters can generally be used without the need for termination resistors. Figures 4, 5a and 5b show typical RS-

485 arrangements with a RS-485/RS-232 converter and a host PC connected to a LAN.

Pulsing Fault Location

For fault location the DSP system is equipped with pulse modulation for the ground current to locate the fault more 

readily. Pulse current is provided at the DSP-DPS (+) and (-) terminals, which may be directly connected to the pulse 

Relay in the DSP-OHMNI-PM. It is important to observe the polarity of the connection. This 12V wiring need not be 

shielded but should be 14 or 16 AWG switchboard wire for durability.

Figure 6: Home Screen

This is the home screen, which is the NORMAL starting screen after RESET is pressed. Various messages may 

modify this screen following an event such a phase fault, loss of fuse, or during pulsing to provide some diagnostic 

information. If the following screen appears and the local alarm sounds, then the DDR2 resistor is likely not energized 

or connected.

Figure 7: Alarm Screen

Summary of Contents for DSP-OHMNI

Page 1: ...C EG30EM Instruction Manual V2 June 2020 DSP OHMNI ...

Page 2: ...tomer service and technical leadership We build on this foundation by investing in developing new products in electrical safety education including EFC scholarship program by actively participating in the IEEE community programs on technical and electrical safety standard and working with local universities at discovering new technologies We remain unrelenting in our goal of improving electrical s...

Page 3: ...odule Status Addresses Table 15 Feeder Module Priority Addresses Table 16 System Function Registers FIGURES Figure 1a Typical One Line Installation Unit Substation Figure 1b DSP DCM Wiring Figure 1c System Module DSP DSM Wiring Figure 1d Power Supply DSP DPS Wiring Figure 2 Preferred Feeder Module DSP DFM Wiring Figure 3 Alternative Sensor Wiring Figure 4 Typical 4 wire Communications Connection F...

Page 4: ...2 NGR Status Good Resistor Figure 33 NGR Fault Figure 34 DSP DRM Not Connected Figure 35 Arc Detection Module Status Page when no DSP ADM is Present Figure 36 Arc Detection Module Status Page with DSP ADM Present and No Alarms Active Figure 37 Arc Detection Module Status Page With DSP ADM Present and Flash Alarm Shown on Channel Figure 38 DIN Rail Mounted Modules Figure 39 DSP DM Display Module wi...

Page 5: ...ity of service e g petro chemical grain handling In this case in addition to fault indication the DSP OHMNI can be programmed to trip the breakers associated with the fault with or without adjustable time delay up to 99 hours The alarm level is normally set at 50 default of the system maximum ground current however with the DSP OHMNI system other alarm levels between 10 and 90 may be set as desire...

Page 6: ...ault 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 provide 5V 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...

Page 7: ...e of these units are shorted normally by a tie breaker contact following an outage of one of the power sources The main breaker on the outage side will open and the tie breaker will close through key interlock or other controls allowing power to be supplied from the live side to the dead side to main tain service and priority allocations to both DSP systems These modules should be installed at the...

Page 8: ... also voltage VNG that is proportional to the neutral resistor voltage i e total leakage fault current of the system The OHMNI PM is connected between ground and the neutral star point of the transformer on wye systems On delta systems an artificial neutral device I Gard type DDAI is required to provide a neutral star point Both OHMNI PM and DDAI devices are selected for appropriate current let th...

Page 9: ...ircuit feeder TxA or Rx yA Toroidal Current Sensor 1 feeder module DSP ADM Arc Detection Module 1 required for arc detection application DSP CA Cable adapter module 1 required for Main Tie Main applications DSP CAS Cable adapter module switch 1 required for Main Tie Main applications Table 4 Standard Ribbon Cables Length Function Catalogue Number 5cm 2 in Module to Module connection RC 3 30cm 12 i...

Page 10: ...es should be run from each sensor X1 and X2 as indicated to prevent cross coupling between modules If existing wiring does not allow this connection because of common connection at X2 as has been common in some installations then the G terminals of the DSP DFM mod ules should be connected as shown in Figure 3 Ribbon cables are available in different lengths as shown in Table 4 For other lengths co...

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 13: ...ctor shielded cable for this purpose The DSP CA S does the same thing except that it includes an electronic switch to make or break the connections when the tie breakers are closed or open The two modules are DIN rail mounted similar to the other DSP modules in 70mm wide housing See information on DSP CA S in manual C 415EM for typical wiring Figure 3 Alternative Sensor Wiring Figure 4 Typical 4 w...

Page 14: ...gh a stan dard RS 485 to RS 232 converter to a PC with supporting software Note the user must supply software to read the registers of the DSP OHMNI system The alarm contacts are available at the DSP DPS as a Form C type and should be connected to operate a horn or other means to alert an operator to the fact that a fault has occurred on the HRG system The contacts are rated at 10A 240V AC resisti...

Page 15: ...current is provided at the DSP DPS and terminals which may be directly connected to the pulse Relay in the DSP OHMNI PM It is important to observe the polarity of the connection This 12V wiring need not be shielded but should be 14 or 16 AWG switchboard wire for durability Figure 6 Home Screen This is the home screen which is the NORMAL starting screen after RESET is pressed Various messages may m...

Page 16: ...ettings screen This page gives access to make changes to system settings Some settings sub pages require Administrative permis sion to access There are two modes of operation Administrative and User To have access to all the settings it is necessary to log in the Admin mode To change between modes just choose the mode on the drop box on the title or When enter on the Admin mode a password will be ...

Page 17: ...s possible to set a Password Hint to help to remember the password in the future Communication To change the communication settings enter Admin mode and from the HOME screen press Settings then press Communication Settings On this screen you have the options to configure both MODBUS RTU and TCP Figure 9 Password Settings Page Figure 10 Communications Set up MODBUS TCP ...

Page 18: ...y one device is used then it will typically be set to 01 which is the default value ensure that no other device has the same I D setting on the MODBUS network or data will not be valid In order to change the number select the field and enter the desired number Then press Save Device ID NGR Alarm Settings To change the NGR Alarm Setttings enter in the Admin mode and from the HOME screen press Setti...

Page 19: ...at it is always on and it is desired to suppress the CHECK DDR2 FUSES alarm that would normally exist when the bus is de energized Normally on the occurrence of an alarm when the MUTE button is pressed the DSP DPS general alarm relay Form C contact on terminals 27 29 31 is reset and the local annunciator is muted This is the operation when the MUTE ALARM setting is ENABLED The default setting for ...

Page 20: ...T FLT TRIP type selection This permits the TRIP and priority of previously set modules to be changed while retaining the same I D number There will likely be duplicate I D numbers prior to the first setup and these will be overwritten by the set up procedure Note If a duplicate I D number has been selected the ACCEPTED result could still be obtained with the result that there will be two or more m...

Page 21: ... 15 Note It is possible to exceed the range of 00 15 and enter priority numbers above 15 but the priority will not be increased and will roll over after 15 to become 00 again To avoid confusion the priorities should be kept within the range 00 to 15 only The DELAY numbers range from 00 to 99 representing the delay for first fault tripping in minutes or hours with 00 representing instantaneous TRIP...

Page 22: ... Page The pulse set up screen allows the pulsing mode for fault location to be changed for different frequencies and mode of operation This screen will show the present PULSE settings The pulse feature resides in the DSP DPS See sec tion 7 for more details Inverted Mode The output from the DSP DPS module is connected to a solid state relay Normally non inverted operation the output ...

Page 23: ...d the Inverted Mode OFF would be selected Pulsing would then change the current to a higher level from 5A to 10A alternating when a 100 fault exists 2 Pulse Down Current Pulsing downwards means to reduce current for example from IGmax 5A to IGmax 2 5A In this case the pulse resistor will be normally ON and thus the Inverted Mode ON mode would have to be selected This means that the solid state rel...

Page 24: ...lock prevents pulsing from occurring when there is no fault on the system Press to toggle ON or OFF to com plete the pulse set up It is recommended to operate the DSP OHMNI system with the lock ON Clock Settings To setup the Pulsing Settings enter in the Admin mode and from the HOME screen press Settings USER SET TINGS Set Date and Time After pressing Ok you can see the current time and date the f...

Page 25: ...s a percentage of the maximum ground current of the system A reading of would represent a direct short to ground for the feeder while 0 represents no current leakage at all STATUS is also indicated which shows whether or not the feeder module is OK leakage below 50 Fault faulted leakage greater than 50 or Trip Tripped which may happen if a second fault caused current in the sensor to exceed 100A f...

Page 26: ...stalled with status NOT DETECTED Note to identify which DSP DFM is which if not sure the user can push the I D TEST button on each DSP DFM until the status indicator on the feeder screen shows Test in blue This will be the FM selected and the I D can be read on this screen Pulsing When a fault occurs it is possible to start and stop Pulsing from the Home Screen by pressing the Activate Pulsing but...

Page 27: ...o ON in the pulse set up In this case pulsing cannot be turned ON unless there is an actual fault on the system This can be easily changed in the set up configuration In User mode the commands Interlock and Inverted Mode are blocked Enter Admin mode to change this configura tion Faults can be located easily with the use of a flexcore sensor I Gard type TS SENSOR Following feeder fault iden tificat...

Page 28: ...n three ways 1 LED Indications DSP DSM system module red ALARM light DSP DFM fault indication is enabled to provide indication if fault is detected by feeder module the fault may not be detected by a feeder module For example if it is on the main bus it won t be detected 2 Alarms DSP DRM red light NGR FAULT lights Alarm relay Form C on DSP DPS will operate to energize customers alarm device horn e...

Page 29: ...rm that this is the faulted circuit In addition there will be an alarm Indication on the faulted feeder module which is indicated by a continuous red LED In the case of TRIP on first fault the LED indicator light on the DSP DFM feeder module will be flashing When the system is faulted it is necessary to determine the source of the fault In some cases this might be known a problem but if the fault ...

Page 30: ... DFM on its side with a fault One other case for this condition is that the feeder module that is faulted red light on is not set up with an I D as priority setting Events and Logging When a fault occurs sufficient to cause an alarm the event is recorded along with the fault current level and location so that it can be checked on the DSP TDM display module even if the fault has disappeared This ca...

Page 31: ...t least 0 5 seconds to be recorded completely particularly with regard to phase indication due to delays in the system module response Note The DSP TDM will not capture faults that occur while the DSP TDM is initializing When an event occurs and is cleared the screen will signal the presence of an event with a left arrow at the lower right hand end of the screen The following events are supported ...

Page 32: ...scribed above the appearance of the open circuit will cause the DSP DRM to switch from the measurement mode to the continu ity mode described above The continuity mode will recognize that the NGR circuit is open and indicate of an NGR failure within 3 5 to 10 seconds DSP DRM Installation See Figure 45 DSP DRM Connections The DSP DRM is designed to be used with an I Gard Type TxA Sensor and a NGRS ...

Page 33: ...NGR OK The LOW V indication may or may not be seen It depends on the voltage that is measured across the NGR grounding resistor Normally this voltage will be low or zero in the absence of a ground fault If sufficient NGR voltage develops then the DSP DRM will begin to moni tor the resistance value of the NGR and signal out of tolerance if necessary Measurement of the actual resistance of the NGR d...

Page 34: ... 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 resist...

Page 35: ...ne up The DSP ADM is designed to be used with SENSOR L1 point light sensors SENSOR F1 modified point sensor with fiber optic tail SENSOR iPS2 or 1PS4 pressure arc sensors The DSP ADM monitors the area to be protected for flashes of light and for air pressure waves caused by arc flashes When any of the sensors identifies such an incident the internal Form C contact transfers This signal is then use...

Page 36: ...amples are shown in the figures 55 below The DSP ADM status line shows the statuses for each of the seven channels When a channel is marked green its status is ok When a channel is marked red it indicates that an arc flash was detected for this channel If the channels are all grey then there is no DSP ADM installed in the DSP lineup Figure 35 Arc Detection Module status page when no DSP ADM is pre...

Page 37: ... or vacuum cleaner during regular switchboard maintenance To test the DSP it will normally be sufficient to use the SELF TEST procedure as described in section 9 To test 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 an...

Page 38: ...r assis tance with installation set up or testing please call I Gard toll free at 1 888 737 4787 1 888 RESISTR There are no user serviceable parts in the DSP therefore all service should be referred to qualified factory representatives other than direct replacement of entire modules to I Gard Please visit the I Gard website at www i gard com for information regarding field service representatives ...

Page 39: ...ts If successful the DSP will return the message shown in table 9 below UNIT I D FUNTION OF BYTES Data 1 DATA 2 CRC 01 03 04 High Low High Low Low High Low 00 nn 00 nn nn nn nn Table 9 Returned Information Structure for Holding Register Request Register contents are shown in Tables 13 to 16 Note Register number is shown in decimal but must be sent in hexadecimal form in the request The only write ...

Page 40: ...spond to requests if the DSP DM is in the SETUP mode The feeder module currents IGf values are contained in the first 50 registers as follows The values range from 0x00 to 0xff although maximum for a first fault condition will be 0x64 or 100 Table 8 lists the register addresses in the MODBUS convention REGISTER NO CONTENTS FORMAT 40001 Feeder 1 I gf 0x00 nn 40002 Feeder 2 I gf 40003 Feeder 3 I gf ...

Page 41: ...r byte is a composite byte upper nibble is mode of operation while lower nibble of nn is pulse frequency 0 9 nn 0n normal interlock OFF 1n inverted interlock OFF 2n normal interlock ON 3n inverted interlock ON 40154 Pulse Status 0x000n n 0 pulsing OFF 1 pulsing ON 40155 Alarm Level 0x000n n 1 10 of NGR current maximum 2 20 3 30 4 40 5 50 6 60 7 70 8 80 9 90 40156 NGR Status 0x00nn nn 00 NGR OK vol...

Page 42: ...ms where P priority setting Priority Levels 0 15 16 settings Contact Ratings DSP DFM Trip Contacts Form C SPDT 10 amperes 240V AC resistive 8A 24V DC DSP DPS Alarm Contacts Form C SPDT 8 amperes 240V AC resistive 8A 24V DC DSP DPS Pulse Output DC Source 100 milliamperes 12V DC maximum Performance DSP DFM Maximum No of Modules 50 Pickup Accuracy 10 of system let through current Trip Level Accuracy ...

Page 43: ... 240V AC 0 35A 24V DC General Temperature Range Operating Temperature 0 C 50 C Standards CSA File Number LR65287 ULListed File Number E232710 CE Dimensions See Fig 37 Note I Gard reserves the right to change specifications of products without notice 10 OUTLINE DIMENSIONS Figure 38 shows typical dimensional details of the polymeric enclosures used for the modules All have the same cross section dim...

Page 44: ...SM 70mm 2 755 in DSP DPS 155mm 6 102 in DSP DRM 155mm 6 102 in DSP CAS 70mm 2 755 in DSP CA 70mm 2 755 in DSP ADM 155mm 6 102 in DSP DCM 70mm 6 102 in Figure 39 DSP DM Display Module with Cut Out Detail Figure 40 DSP DPS Power Supply Connections ...

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 48: ...Admin Mode How to Configure MODBUS TCP This series of videos provides step by step answers to commonly asked questions about IC2 operation Click on the video titles below to be redirected to each video on www i gard com or scan the QR code to be directed to the video on your smartphone ...

Page 49: ... and Export How to Configure MODBUS RTU How to Set Date and Time How to Set Password How to Activate Pulsing How to Configure Feeder Modules How to Read and Interpret System Status How to Change Operating Language How to Identify Feeder Modules ...

Page 50: ...www i gard com Phone 905 673 1553 Toll Free 1 888 737 4787 Fax 905 673 8472 sales i gard com ...

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