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Precision Digital PD686 3½ Digit NEMA 4x Loop-Powered Meters

3½ Digit NEMA 4x Loop-Powered Meters
PD686

The only tools needed for calibration are a calibrated current source and a screwdriver.

Calibration Connections - To access the input terminals it is necessary to remove the enclosure cover and the Display PCB. This is done by loosening the four screws on the enclosure cover and removing the cover. Completely loosen the left screw that holds the Display PCB to the enclosure and loosen the right screw about four turns so the Display PCB remains attached to the enclosure. Rotate the Display PCB 90° to gain access to the Input Signal PCB. Next, connect a calibrated current source.

Decimal Point Selection - The decimal point jumper array is located in the lower right corner of the Display PCB next to the display. It is labeled DP1, DP2, DP3. Place a jumper over both pins of DP1 for a display of 199.9, DP2 for 19.99, or DP3 for 1.999.

Calibration - LO and HI calibration controls are located to the left of the display. Apply a signal equal to 4 mA and adjust the LO control to display the desired reading. Apply a signal between 16 and 20 mA and adjust the HI control to display the desired reading. Complete the calibration procedure by making any minor adjustments to the LO and HI controls.

Installation - Installation of the meter involves removing the Display PCB from its enclosure and connecting a 1/2″ conduit fitting to the hole provided. Refer to PD686 FM Approved & CSA Certified Loop-Powered Meter Intrinsic Safety Barrier Connections diagrams (LIM686-2) for further details. Wall mounting holes are located in each corner of the enclosure.

Loop Connections - Disconnect power to the loop and install the meter as illustrated in Figure 2 and the PD686 FM Approved & CSA Certified Loop-Powered Meter Intrinsic Safety Barrier Connections diagrams (LIM686-2) supplied with the instrument. Replace the enclosure cover.

Removing Display PCB From the Loop - The Display PCB and Input Signal PCB are connected together with one black and one red wire. The wires are soldered to the Display PCB and connected to a screw terminal connector on the Input Signal PCB. To remove Display PCB:
  1. Loosen the four screws on the enclosure cover and remove the cover from the enclosure base.
  2. Completely loosen the left-side screw holding the Display PCB to the enclosure and loosen the right-side screw four turns so the Display PCB remains secure to the enclosure.
  3. Rotate the Display PCB 90° to gain access to the Input Signal PCB.
  4. Install Loop Jumper over both pins to bypass Display PCB and allow the signal to flow through the Loop Jumper. The display turns off when jumper is installed.
  5. Disconnect the black and red signal wires from the screw terminal connector.
  6. Loosen completely the right-side screw and lift Display PCB from enclosure. Care should be taken to prevent static electricity from damaging the electronic circuitry.
  7. Restore enclosure cover to the base to prevent contamination of components.

Restoring Display PCB to the Loop
  1. Remove enclosure cover as described above in step 1.
  2. Secure Display PCB to enclosure using right-side screw; do not tighten screw to allow rotation of Display PCB while accessing Input Signal PCB.
  3. Connect red wire to S+ terminal and black wire to S- terminal.
  4. Remove Loop Jumper to allow the signal to flow through Display PCB (save push-on jumper by placing over one pin only).
  5. Tighten screws holding Display PCB and install enclosure cover.

• 1 V Drop
• 1 High Display
• Operates From -40 to 85°C

Select a link under the "item" tab below to order.

Cat #Descriptions½” Conduit Hole Location
PD686FM Approved & CSA CertifiedBottom
PD686-XFM Approved & CSA CertifiedRear
PD686-YFM Approved & CSA CertifiedTop
PD686-ZFM Approved & CSA CertifiedNone
Input: 4-20 mA @ 30 VDC maximum
Display: 1.0" (25.4 mm) LCD, 3½ digits; 1999
Accuracy: ±0.1% FS ±1 count
Decimal Point: FM Approved & CSA Certified as intrinsically safe with entity, for use in Class I, II, III, Division 1, Groups A, B, C, D, E, F, & G; T-code = T4; hazardous locations. Non-incendive for use in Class I, II, III, Division 2, Groups A, B, C, D, F, & G.
Entity Parameters: Vmax= 30 V, Imax = 175 mA, Ci = 0 μF, Li = 0 μH, Pi = 1.3 W
FM Approved: Intrinsically Safe, Class I Zone 0
Decimal Point: User selectable
Calibration: Two-step; non-interacting zero and span
Calibration Range: 4 mA input: -1000 to +1000;
20 mA input: between 20 and 2000 counts > 4 mA display
Display Update Rate: 2.5/second
Maximum Input Current: 30 mA
Maximum Voltage Drop: 1 V @ 20 mA
Operating Temperature: PD686: -40 to 85°C for Canadian installations -40 to 40°C.
Storage Temperature: -40 to 85°C
Relative Humidity: 0 to 90% non-condensing
Enclosure: Impact-resistant glass filled polycarbonate body, color: gray; impact-resistant clear polycarbonate cover; NEMA 4X, IP67
Connections: Removable screw terminals accept 12 to 26 AWG
Conduit Hole: One ½" conduit hole provided; refer to Ordering. Information to specify conduit hole location; request models with rear conduit hole (-X) for panel mounting applications.
Weight: 12 oz (340 g)
Warranty: 2 years parts & labor


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