Precision Digital PD685-X, PD685-Y, PD685-Z User Manual

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MODEL PD685 3½ DIGIT NEMA 4X

LOOP-POWERED METER

MODEL PD685

Actual Size Digits

1 V Drop• 1" High Display• Operates From •

-40 to 85°C

SPECIFICATIONS

Except where noted all specifications apply to operation at +25°C.

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: 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: -40 to 85°C Storage Temperature: -40 to 85°C Relative Humidity: 0 to 90% non-condensing Enclosure: Impact-resistant plastic; body: gray ABS; cover: clear

polycarbonate; NEMA 4X, IP66/67

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

Disclaimer

The infor mation contained in thi s d ocument is sub ject to chang e w ithout notice. Preci sion Digital Corporation makes no representations or warranties with respect to the contents hereof, and

specically disclaims any implied war ranties of merchant ability or tness for a particular purpose.

ORDERING INFORMATION

PD685 NEMA 4X Loop-Powered Meter

Model Description

PD685 3½ Digit Loop-Powered Meter Bottom

PD685-X 3½ Digit Loop-Powered Meter Rear

PD685-Y 3½ Digit Loop-Powered Meter Top

PD685-Z 3½ Digit Loop-Powered Meter None

Accessories

Model Description

PDA6844

PDA6845 2" Pipe Mounting Kit (zinc plated steel)

PDA6845-SS 2" Pipe Mounting Kit (stainless steel)

Panel Mount Kit (does not provide NEMA 4X seal to panel)

Your Local Distributor is:

½" Conduit

Hole Location

Precision Digital corPoration

www.predig.com

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MODEL PD685 3½ DIGIT NEMA 4X LOOP-POWERED METER

SIDE VIEW

Mounting Holes Located Beneath Cover Screws

FRONT VIEW

A C

Figure 4

Dimensions and Mounting Information

LO CALIBRATION CONTROL

HI CALIBRATION CONTROL

BALANCE CONTROL (factory adjust only)

DISPLAY PCB COMPONENT SIDE (may be removed for bench calibration)

S-

S+ S-

S+

BLACK

RED

LOOP JUMPER

CALIBRATED

CURRENT SOURCE

INPUT SIGNAL PCB (mounted to base of enclosure)

DP1 DP2 DP3

Figure 1

Calibrator Connected to

Input Signal PCB

INPUT SIGNAL PCB

LOOP JUMPER

(remove when Display PCB is connected)

TRANSMITTER

POWER SUPPLY

4-20mA

S+ S+S- S-

Field wiring is made to the Input Signal PCB which is mounted to the base of the enclosure.

Figure 2

Control loop Connected

to Input Signal PCB

S+ S-

BLACKRED

DISPLAY PCB COMPONENT SIDE

CALIBRATED

CURRENT SOURCE

DP1 DP2 DP3

Figure 3

The Display PCB may be removed from the enclosure

for bench calibration. Loop Jumper must be installed

on Input Signal PCB to maintain loop,

refer to procedures below.

Calibrator Connected to Display PCB

Protect enclosure from exposure to chemical solvents and excessive ultraviolet (UV) light (e.g. sunlight).

NOTE: To prevent damage to electronic components caused by electrostatic discharge, a grounding strap should be worn when servicing the display.

Conduit Installation Instructions

1. Remove the Display PCB from the enclosure

2. Connect ½” conduit fittings to the hole in the enclosure

3. Connect conduit (with attached hubs*) to the enclosure * Use only conduit hubs that are designed to maintain NEMA 4X or IP ratings. Note: Please read PD686 Intrinsic Safety Barrier Connections for more information pertaining to conduit holes.

Mounting Instructions

1. Remove the enclosure cover from the base.

2. Insert mounting hardware into mounting holes in enclosure base (see Figure 4).

3. Secure the enclosure base to the mounting surface using the inserted hardware.

4. Re-attach the enclosure cover to the base.

SETUP

Only a calibrated current source and a screwdriver are needed for calibration.

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 as illustrated in Figure 1.

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 (see Figure 1). 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 conduit fitting. Use conduit and fittings (not included) suitable for the degree of ingress protection required. Mounting holes are located at each corner of the enclosure. Refer to Figure 4.

Loop Connections

Disconnect power to the loop and install the meter as illustrated in Figure 2. Replace the enclosure cover.

Precision Digital corPoration

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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. 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 will go off when the jumper is installed. Disconnect the black and red signal wires from the screw terminal connector.

6. Loosen completely the right-side screw and lift Display PCB from the 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 in step 1 in the preceding section.

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, as shown in Figure 1.

4. Remove Loop Jumper to allow the signal to flow through Display PCB (save pushon jumper by placing over one pin only).

5. Tighten screws holding Display PCB and install enclosure cover.

Servicing Display PCB Outside the Loop

Two modes of input signal allow the user to remove the Display PCB for service without interrupting the loop as indicated above and operate the Display PCB at another location. The loop remains connected to the Input Signal PCB while the Display PCB is absent for service. The user may operate the Display PCB at another location by connecting a signal to the S+ and S- wires on the Display PCB as illustrated in Figure 3.

A: 3.15" (80 mm) C: 2.36" (60 mm) E: 2.56" (65 mm) B: 5.51" (140 mm) D: 4.72" (120 mm) F: 0.79" (20 mm)

LDS685_C 06/09

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