8400100.qxp 3/20/2006 3:20 PM Page 150 Flat Pack Series 270i Isolator Diagram Isolated Transmitters PLC / DCS + + + 270i Field 4-20mA 4-20mA OUT IN OUT Device R – – – L 250T Isolator Diagram PLC / DCS + + + + Field 250T 4-20mA 4-20mA IN OUT Device – – – – 24V DC R L 4-20mA Source 270i Isolators For more information about the 250T Transmitter, refer to Page 144. DC Current Input n Special Features n Performance The 270i accepts a process current input and provides an isolated 4 to 20mA process current n Excellent accuracy and stability ensure reliable n Input output signal. Power is received from the input measurements in harsh industrial environments. Input Range signal current. 4 to 20mA input. Power is derived from the input sig- n 1500V AC peak isolation (250V AC or 354V nal loop. Input current should be limited to less than These isolators use transformer isolation to DC continuous) prevents ground loops. 50mA to prevent damage to the isolator. In the event effectively break the electrical path between the of an open output circuit, the input loop voltage drop n RFI and EMI resistance minimize the effects of is limited to 20V, nominal. Isolator has reverse polarity transmitted signal and the receiving device. This environmental noise. protection. eliminates ground loops, reduces noise, and Zero and span helps protect against transients for more n Calibration is independent of the load to Zero and span trim adjustments utilize 22-turn poten- accurate and reliable measurements. eliminate load compensation adjustments tiometers accessible from front of the unit. This product is also extremely easy to install. n Zero and span adjustment enable precise Input voltage drop The voltage drop is a function of the input current and All units are factory calibrated for loads up calibration. load resistance and is calculated as follows: to 600 ohms to eliminate any need for load n Compact, 1-inch wide housing uses less space Input Voltage Drop = 5.4V DC + (0.0216A x RLOAD trim adjustments. for easier installation in control panels. Example (RLOAD = 250 ohms): Input Voltage Drop = Input Range n Input current sense resistor simplifies field 5.4V DC + (0.0216A x 250 ohms) = 10.8V DC. n 4 to 20mA DC diagnostics Current sense resistor A built-in 10 ohm (±0.1%) resistor can monitor input Output Range current to the isolator. Wiring to the isolator's input n 4 to 20mA DC terminals determines if this resistor is included in the current loop. Use of this resistor provides a test signal Power Requirement of 40 to 200mV, representing 4 to 20mA. n 12 to 50V DC @ 20mA (loop-powered), Continued on the next page. power is derived from the input signal current. Loop-burden: 10.8V@250 ohm output load. Approvals CSA: C22.2 No. 142 Class I; Division 1; Groups A, B, C, D Class I; Division 2; Groups A, B, C, D Class II; Division 1; Groups E, F, G Tel: 248-295-0880 Fax: 248-624-9234 e-mail: sales@acromag.com www.acromag.com 150 Flat Pack Flat Pack 8400100.qxp 3/20/2006 3:20 PM Page 151 Isolated Transmitters Performance (continued) n Ordering Information Select one option from each column. Example: 270i-20MA-DIN-NCR n Output Output Range Base Input Mounting Approval 4-20mA DC output. A. For RLOAD from 50 to 600 ohms, connect RLOAD 270i -20MA -DIN -N4 -NCR between Output (+) and Output (-) terminals. -ST -N12 -DT1 B. For RLOAD from 0 to 50 ohms, connect RLOAD -SM -XP - between Output (S) and Output (-) terminals. For optimum performance at low values of RLOAD, the iso- lator has a built-in pad resistor of 50 ohms. Input Options Ordering Notes 1. Input Voltage Drop (input sense resistor not used): VDROP = 5.4V DC + (0.0216A x (RLOAD + 50 ohms)) -20MA: 4.0 to 20.0mA DC * Unit requires factory calibration. Append “-C” to end of model number. Specify ranges on order. 2. Input Voltage Drop (input sense resistor used) Mounting Options VDROP = 5.6V DC + (0.0216A x (RLOAD + 50 ohms)) † Units are shipped separately from any optional Mountings enclosures (i.e. units are not installed in any external Accuracy -DIN: DIN rail G or T mount housing). ±0.1% of output span. Error includes the combined -ST: SNAPTRACK mount effects of isolator repeatability, hysteresis, terminal †† Units shipped installed in external enclosure. point linearity and adjustment resolution. -SM: Surface-mount Accessories Load resistance effect External housings Power supplies Less than ±-0.1% of output span as load resistance is -N4: NEMA 4, water-tight, holds two See Power Supplies on Page 199. changed over entire range. Allows use of isolator, within -N12: NEMA 12, oil-tight, holds two resistance load range, without the need to recalibrate DIN RAIL 3.0 -XP: Explosion-proof NEMA 4, holds one the isolator for a particular load. DIN RAIL 16.7 DIN rail strip, Type T, 3 inches (75mm) or Output ripple Approval Options 16.7 inches (425mm) Less than ±0.1% of the maximum output span. -NCR: No certification/approval required. 20RM-16-DIN Bandwidth -. 19" rack-mount kit with DIN rail. -3dB at 3Hz, typical. † Holds sixteen 270i isolators. -DT1 : CSA approval, Div. 2 hazardous locations: Response time Class I; Div. 2; Groups A, B, C, D. For a step input, the output reaches 98% of output †† span in 180mS, typical. -EP1 : CSA approval, Explosion-proof for hazardous locations: Class I; Groups B, C, D Class II; Groups E, n Environmental F, G. NOTE: Only available with explosion-proof Ambient temperature range housing (-XP). Operating: -13 to 185°F (-25 to 85°C). Storage: -40 to 185°F (-40 to 85°C). Ambient temperature effect Less than ±0.006% of output span per °F (±0.01% per °C) over the ambient temperature range for refer- ence test conditions. This specification includes the combined effects of zero and span over temperature. Isolation The input and output circuits are isolated from each other for common-mode voltages up to 250V AC, or 354V DC off ground, on a continuous basis (will with- stand 1500V AC dielectric strength test for one minute without breakdown). Noise rejection Common mode: 110dB at 60Hz, typical. RFI resistance Less than ±0.5%, of output span effect. EMI resistance Less than ±0.25% of output span effect. Surge withstand capability (SWC) Input/Output terminations rated per ANSI/IEEE C37.90- 1978. Unit is tested to a standardized test waveform that is representative of surges (high frequency transient electrical interference), observed in actual installations. Tel: 248-295-0880 Fax: 248-624-9234 e-mail: sales@acromag.com www.acromag.com 151