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LP420
LOOP POWERED
DISPLAY

FEATURES
bulletProvides 3 1/2 Digit Liquid Crystal (LCD) Readout Proportional to a Process Loop Current
bulletLoop Powered
bulletTrailing Dummy Zero (±19990)
bulletSwitch-Selectable Engineering Units/Loop Current Display
bulletExplosion-Proof Housing
bullet5 + 5 Year Warranty


DESCRIPTION

The LP420 Loop Powered Display provides digital indication of a 4/20 mA or 10/50 mA process loop signal. The display takes its operating power from the loop current and requires no other source of power.

Wide-ranging zero and span adjustments plus switch-selectable decimal point location and trailing zero allow the display to be calibrated in engineering units. An Engineering Units/Loop Current switch permits a quick check of the process signal without recalibration.

The LP420 is mounted in an explosion-proof housing and operates from -40° to 185°F (-40 to 85°C). The circuit boards are conformal coated for protection from humidity and contamination.

TYPICAL APPLICATIONS

Displaying process variables where line power is NOT available, and in hazardous (explosive) atmospheres.

MOUNTING

The LP420 is mounted in a Killark HK Series explosion-proof housing.

SPECIFICATIONS

INPUT RANGE
4/20 mA or 10/50 mA

INPUT VOLTAGE DROP
3.5V max 
  (equivalent to  175 ohms at 20 mA or
  70 ohms at 50 mA)

DISPLAY
Digit Size
  0.35 inch LCD, 3 1/2 digits, ± 1999

Switchable Decimal Points and Trailing Zero
  ±1.9.9.90

Control Range
  Zero
    ±1999
  Span
    min span 10/max span 3998
      (full scale minus zero)

Update
  3/sec

DISPLAY SWITCH
allows quick check of loop current
  (400/1999 or 100/500)
    Decimal point remains in Engineering
    Units position. 

ACCURACY
±(0.05% of reading plus 1 digit)

OPERATING TEMPERATURE 
 -40°F to 185°F 
 -40°C to 85°C 

TEMPERATURE STABILITY
±(0.01% of span plus 0.01% of display zero offset)/°C

POWER
 supplied by input current
  no separate power required

HOUSING
 explosion-proof (Killark HK series)

Housing is FM Approved and CSA Certified for the following locations:
  Class I, Divisions 1 and 2;
    Groups B, C, and D
  Class II, Divisions 1 and 2;
    Groups E, F, and G
  Class III, NEMA 3, 4, 7 and 9

International Approvals (IEC)

* HK series enclosures are designed to meet flameproof requirements as defined by CENELEC (EURONORM Standard 50018)

* BASEEFA Certified


TERMINAL CONNECTIONS
 Current +
Current -
Tie Points 		PIN +
PIN -
PIN Center Pins