OMNITERM LPI & LPD Loop Powered Isolators DATASHEET. Model C2063B LPI (single) & C2462A LPD (dual) 4-20mA Loop Powered Isolators.

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1 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Features Isolate any instrument current loop to 0ac Powered by the current loop no power supply required Lowest volt drop < Volts at 0 ma (,V Typical) Load independent no field calibration ever required High kohm load capability High 0.% Accuracy High.mm per channel packing density everse polarity and overload protection Unique internal clamp can protect against open circuit. Internal 0 ohm resistor for V input to PLC s etc. Easy D rail or surface mounting DATASHEET The OMNITEM and LPD are loop powered isolating current repeaters specifically designed to isolate instrument current loops from circulating ground currents that can cause system inaccuracies, or at worst, instrument failure. Insert in any 0mA current loop to isolate the instruments in the loop. The current applied to the input is repeated on the isolated output, and the load present on the output is reflected back to the input. No separate power source is required. Forming part of OMNIFLEX s extensive OMNITEM range of signal conditioning and signal isolation products, the OMNITEM and LPD are designed to be D rail or surface mounted. The Omniterm is a single loop isolator in a.mm wide D rail mount housing with extensive additional connection features, while the LPD is a dual loop isolator that fits two separate channels into the same.mm width for high density applications. These secondgeneration products utilise advanced electronic techniques to achieve high accuracy with minimum loop losses and zero field calibration. Applications Because of the faithful nature in which the output impedance is reflected back to the input, an open circuit on the output will cause an open circuit on the input. In cases where this is undesirable, an internal clamp is provided in the model which, when connected, ensures that the current loop is not broken if the load is disconnected, such as unplugging the input terminations of a PLC or TU. In many applications there is a need to convert the 0mA into Volts for an TU, PLC or DCS etc. This is normally inconvenient because the precision resistor needs to be sourced, mounted and wired independently without causing loop errors. To overcome this obstacle, the version also includes a precision 0ohm resistor that can be connected into the circuit to convert the output into V within the module. The and LPD operate over 00mA range, allowing fault current levels to be repeated. Mechanical Details Isolate instruments in the same current loop Prevent ground loops and eliminate loop errors Isolate TU s, PLC s, SCADA I/O from the field loop. Isolate twowire transmitter loops from local Volts Isolate grounded chart recorders from the field loop. 0 Isolate grounded control valves from the transmitter Can be used with twowire or fourwire transmitters Isolate and convert two wire field devices to V Datasheet DSC0B0 sheet of

2 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Connection Diagram Connect to for V on 8 Connect to for V on Clamp 0mA input Output Clamp 0mA output Operating Current ange Absolute maximum current range voltage Maximum volt drop in loop Terminal Configuration of Omniterm (Model C0B) [NB: Note terminal numbering is out of order to be backward compatible with the model C0] 0mA input Max. equivalent insertion loop resistance Output Output current Min. load impedance (externally connected) Max. load resistance (without open circuit clamp connected) Performance 8 LPD 0mA input 0mA output 0mA output Terminal Configuration of Omniterm LPD (Model CA) 0mA 00mA V maximum volts at 0mA 0Ω at 0mA Matches input current 00Ω or Volts kω at 0 ma for Volts Supply Accuracy at 0 C and 0Ω load < 0uA between and 0mA Effect of load impedance Effect of Temperature esponse time 090% of 0mA into 0Ω < 0.%/00Ω 0,0%/00Ω typical < 00ppm/ C 0ms typical Open Circuit Clamp (when connected on only) Maximum voltage across input when output open circuit Maximum working load impedance allowed with clamp connected. <8 volts Internal 0Ω esistor when connected ( only) esistance 0Ω ± 0.% esistance change with temperature 0ppm/ C Specifications Temperature Storage Operating Isolation Isolation Test Voltage Weight 0 to 0 C 0 to 0 C 0rms to Output Model C0B LPD Model CA Unpacked g approx. 0g approx. Packed 0g approx. 8g approx. Compliance to Standards Safety EN 090:99 Emissions EN0 & EN008:99 Gp I, Cl A Immunity ESD IEC 000:99, level Immunity F Fields IEC 000:99, level Immunity Fast Transients Housing IEC 000:99 kv input/output lines Width.mm (.8 ) Height Depth (from panel) Material Terminals Ordering Information Model LPD mm(.9 ) 0mm(. ) ABS Flammability Class HB as per UL9 Screwclamp.0mm wire size max. Order Code C0B CA Datasheet DSC0B0 sheet of

3 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application Examples Application : Using the to isolate a powered 0mA transmitter output from a resistive load Powered 0mA Output 0mA 8 0mA 0mA L This is the basic circuit for inserting a Loop Powered Isolator () into a current loop. The can simply be cut into any existing current loop to isolate the current transmitter from the load. NOTE: The side of the is always connected to the side of the loop supplying the loop power. The will consume less than Volts of the available loop voltage. This is equivalent to inserting less 0 ohms of additional resistance into the current loop. To determine the maximum loop resistance that you can tolerate in your cabling, apply the following formula: = T L 0 is the maximum resistance in the loop without causing measurement error. T is the maximum load resistance that the current transmitter can drive. L is the total resistance of all loads in the loop (excluding the ) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

4 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the to isolate a field mounted 0mA twowire transmitter from a PLC, TU or DCS Loop Powered Twowire Transmitter 0mA V 0mA 0mA L 8 This is the basic circuit for isolating a fieldmounted twowire transmitter from the control circuitry using an. The can simply be cut into any existing twowire current loop to isolate the transmitter from the panel power supply. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the twowire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, For multiple loops where space is a concern, use the LPD dual module. (See Application, 8 and 9) The will consume less than Volts of the available loop voltage. This is equivalent to inserting less 0 ohms of additional resistance into the current loop. To determine the maximum loop resistance that you can tolerate in your cabling, apply the following formula: ( VS min T = min) L V.0 0 is the maximum resistance in the loop without causing measurement error (in Ohms). V Smin is the minimum voltage of the power supply used to drive the loop (in Volts). V Tmin is the minimum voltage required by the twowire transmitter for operation (in Volts). L is the total resistance of all loads in the loop (excluding the ) (in Ohms) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

5 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the s internal resistor with a wire transmitter to provide V to a PLC/TU/DCS Loop Powered Twowire Transmitter 0mA V V V 8 There are many cases when using 0mA inputs to your PLC or TU or DCS is inconvenient. For example:. Your analogue input does not support 0mA, and mounting an external resistor is inconvenient.. Your analogue input has plug in terminals, and you do not want to lose power to your field transmitter or disrupt the loop if the terminal block is unplugged. In these cases you can use the internal resistor on the side of the to conveniently convert your 0mA signal into a V signal. For the most accurate result, ensure that the reference of the (terminal 8), and the reference of your analogue input are referenced to the same point. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the twowire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, The will consume less than Volts of the available loop voltage. This is equivalent to inserting less 0 ohms of additional resistance into the current loop. To determine the maximum loop resistance that you can tolerate in your cabling in this application, apply the following formula: ( VS min V min ) 00.0 = T is the maximum resistance in the loop without causing measurement error (in Ohms). V Smin is the minimum voltage of the power supply used to drive the loop (in Volts). V Tmin is the minimum voltage required by the twowire transmitter for operation (in Volts). A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

6 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the s internal resistor with a wire transmitter to provide V to a PLC/TU/DCS 8 V V 0mA There are many cases when using 0mA inputs to your PLC or TU or DCS is inconvenient. For example:. Your analogue input does not support 0mA, and mounting an external resistor to convert the signal to V is inconvenient.. Your analogue input has plug in terminals, and you do not want to lose power to your field transmitter or disrupt the loop if the terminals are unplugged. In these cases you can use the internal resistor on the side of the to conveniently convert your 0mA signal into a V signal. For the most accurate result, ensure that the reference to the (terminal ), and the reference of your analogue input are referenced to the same point. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the fourwire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, The will consume less than 8 Volts of the available loop voltage. This is equivalent to inserting less than 00 ohms of resistance into the current loop. To determine the maximum loop resistance that you can tolerate in your cabling in this application, apply the following formula: = T 00 is the maximum resistance in the loop without causing measurement error (in Ohms). T is the maximum load resistance that the current transmitter can drive (in Ohms). A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

7 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the s internal clamp with a wire transmitter to protect the loop against open circuit. Loop Powered Twowire Transmitter 0mA V 0mA 0mA L 8 There are cases, when using 0mA inputs to your PLC, TU or DCS, where it is important that the current loop is not disrupted when the analogue input to your PLC or TU or DCS is unplugged or disconnected. In these cases you can use the internal clamp of the to protect the loop from open circuit if your PLC or TU or DCS input is unplugged or disconnected. This is simply achieved by connecting the input clamp terminal to your reference. If the analogue input to your PLC or TU or DCS is disconnected, the current will be diverted to through the clamp, saving the current loop from disconnection. The voltage across the will be clamped to.8volts in this condition only slightly higher than the normal operating voltage of Volts. This higher clamp voltage should be used when calculating maximum allowable loop resistance. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the twowire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop with the clamp in operation, apply the following formula: ( VS min V min ) 00.0 = T is the maximum resistance in the loop without causing measurement error (in Ohms). V Smin is the minimum voltage of the power supply used to drive the loop (in Volts). V Tmin is the minimum voltage required by the twowire transmitter for operation (in Volts). A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

8 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the s internal clamp with a wire transmitter to protect the loop against open circuit. 8 0mA 0mA 0mA L When using 0mA inputs to your PLC, TU or DCS, there are cases where it is important that the current loop is not disrupted when the analogue input to your PLC or TU or DCS is unplugged or disconnected. In these cases you can use the internal clamp of the to protect the loop from open circuit if your PLC or TU or DCS input is unplugged or disconnected. In fourwire current transmitter applications this is simply achieved by connecting the output clamp terminal to the current output terminal of the. If the analogue input to your PLC or TU or DCS is disconnected, the current will be diverted through the clamp, saving the current loop from disconnection. The voltage across the will be clamped to.8volts in this condition slightly higher than the normal operating voltage of Volts. This higher clamp voltage should be used when calculating maximum allowable loop resistance. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the fourwire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop with the clamp in operation, apply the following formula: = T 00 is the maximum resistance in the loop without causing measurement error (in Ohms). T is the maximum load resistance that the current transmitter can drive (in Ohms). A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet 8 of

9 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application : Using the LPD to isolate multiple 0mA Outputs from a PLC or DCS TU/ PLC/ DCS 8 0mA 0mA LPD 0mA 0mA 0mA s L L 0mA input In this application, the LPD can be inserted directly into the 0mA output loops between the transmitter and the load. Each LPD circuit will consume less than Volts from the loop. For loop resistance calculation purposes this is equivalent to inserting an additional resistance of 0 ohms into the current loop. NOTE: The side of the LPD is always connected to the side of the loop supplying the loop power, and so in this application, the Transmitter outputs are connected to the side of the LPD. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop, apply the following formula: = T L 0 is the maximum resistance in the loop without causing measurement error (in ohms). T is the maximum load resistance that the current transmitter can drive (in ohms). L is the total resistance of all loads in the loop (excluding the ) (in Ohms) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet 9 of

10 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application 8: Using the LPD to isolate multiple 0mA inputs to a PLC or TU (with passive inputs) Vdc 0mA 0mA 8 LPD 0mA 0mA 0mA Passive inputs L TU/ PLC L In this application, the LPD can be inserted directly into the 0mA input loops between the field mounted twowire transmitter and the PLC or TU input. Each LPD circuit will consume less than Volts from the loop. For loop resistance calculation purposes this is equivalent to inserting an additional resistance of 0 ohms into the current loop. NOTE: The side of the LPD is always connected to the side of the loop supplying the loop power, and so in this application, the twowire transmitters are connected to the side of the LPD. Because of the mm wire size capability of the LPD terminals, the LPD can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop, apply the following formula: ( VS min T = min) L V.0 0 is the maximum resistance in the loop without causing measurement error (in Ohms). V Smin is the minimum voltage of the power supply used to drive the loop (in Volts). V Tmin is the minimum voltage required by the twowire transmitter for operation (in Volts). L is the resistance of the PLC/TU input (in Ohms) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet 0 of

11 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application 9: Using the LPD to isolate multiple 0mA inputs to a DCS with active (twowire tx) inputs. 0mA Twowire inputs Looppowered Twowire Transmitters 0mA 0mA 8 LPD 0mA 0mA V L L DCS In this application, the LPD can be inserted directly into the 0mA input loops between the field mounted twowire transmitter and the DCS input. Each LPD circuit will consume less than Volts from the loop. For loop resistance calculation purposes this is equivalent to inserting an additional resistance of 0 ohms into the current loop. NOTE: The side of the LPD is always connected to the side of the loop supplying the loop power, and so in this application, the twowire transmitters are connected to the side of the LPD. Because of the mm wire size capability of the LPD terminals, the LPD can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop, apply the following formula: ( VS min T = min) L V.0 0 is the maximum resistance in the loop without causing measurement error (in Ohms). V Smin is the minimum voltage of the power supply used to drive the loop (in Volts). V Tmin is the minimum voltage required by the twowire transmitter for operation (in Volts). L is the resistance of the PLC/TU input (in Ohms) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of

12 Model C0B (single) & CA LPD (dual) 0mA Loop Powered Isolators Application 0: Dealing with zero loop resistance when using the. Powered 0mA Output 0mA 8 0mA 0mA L < 00ohms The is optimised to minimise the effective inserted loop impedance, but does require a minimum of 00 ohms of load impedance, (or volts) on the output to maintain operation. In some applications, when using fourwire transmitters, the load being driven is lower than this minimum value, and additional load needs to be inserted into the output loop to bring the minimum load up to the required 00 ohms. One solution for this is to use the internal 0 ohm resistor to provide this additional resistance. When connected as shown in the diagram above, the internal resistor is used in series with the current loop to provide an additional 0 ohms of loop resistance. This brings the back into specification without the need for any additional resistors. NOTE: The side of the is always connected to the side of the loop supplying the loop power, so in this application the fourwire transmitter is connected to the terminals of the. Because of the mm wire size capability of the terminals, the can also act as the field interface terminals, To determine the maximum loop resistance of your cabling that you can tolerate in your loop with the clamp in operation, apply the following formula: = T L 00 is the maximum resistance in the loop without causing measurement error (in Ohms). T is the maximum load resistance that the current transmitter can drive (in Ohms). L is the resistance of the connected load (in Ohms) A sensible value to use for this safety factor would be 00 ohms (equal to Volts at 0mA). Datasheet DSC0B0 sheet of