Precision Digital ISO 9001:2000 Certified Quality System

Setup	Calibration	Decimal Point Selection	Loop Connections

Dimensions	Specifications	Ordering Information	Documentation

FM & CSA LOOP-POWERED METER

Features

4-20 mA Input
NEMA 4X
1 V Drop
3½ Digit LCD 1" (25.4 mm) High
Operating Temperature Range: -40 to 85°C
½ Conduit Hole Provided
Intrinsically Safe with Entity
Class I, II, III; Div. 1; Gp A, B, C, D, E, F, G
Non-incendive:
Class I, II, III; Div2; Gp A, B, C, D, F, G

The PD686 can be installed just about anywhere in North America: indoors, outdoors, hot, cold, safe or hazardous area. It has been approved by FM and CSA as instrinsically safe and non-incendive, will operate from –40 to 85°C, and adds only 1V to the loop. Its big 1 inch high display means it can be read from considerable distance. Calibration is a quick two-step process involving the adjustment of only two non-interacting potentiometers.

Note: For complete installation information see instruction manuals below

Setup

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 per Figure 1 to the right.

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.

Figure 1: Calibrator Connected to Input Signal PCB

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 for further details. Wall mounting holes are located in each corner of the enclosure (Figure 1 shown above).

Loop Connections

Loop-Powered Indicator PD686 FM Approved & CSA Certified Meter Intrinsic Safety Barrier Connections Diagrams

Figure 2: Control loop Connected to Input Signal PCB

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

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

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 in a non-hazardous area. 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 "S+" and "S-" wires on the Display PCB. Refer to Figure 3 to the right.

The Display PCB may be removed from the enclosure for bench calibration. Loop Jumper must be installed on Input Signal PCB to maintain loop.

Loop Powered Indicator PD686 FM Approved & CSA Certified Meter Display PCB Outside the Loop

Figure 3: Calibrator Connected to Display PCB

Dimensions and Wall Mounting Information

Loop-powered Indicator Dimensions and Mounting Spec for PD686

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)

Figure 4

Specifications

General

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
Approvals: 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: V_max= 30 V, I_max = 175 mA, C_i= 0 µF, Li = 0 µH, P_i = 1.3 W
FM Approved: Intrinsically Safe, Class I Zone 0
See Control Drawing LIM686-2 for complete installation instructions.
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
Extended Warranty: 1 or 2 years

Disclaimer
The Information contained in this document is subject to change without notice. Precision Digital Corporation makes no representations or warranties with respect to the contents hereof, and specifically disclaims any implied warranties of merchantability or fitness for a particular purpose.

ORDERING INFORMATION Products
Model	Description	Price
Blue dot denotes item as a Quick Ship product
PD686	FM Approved & CSA Certified Loop-Powered Meter NEMA 4X; ½" Hole Bottom	$309.00
PD686-X	FM Approved & CSA Certified Loop-Powered Meter NEMA 4X; ½" Hole Rear	$309.00
PD686-Y	FM Approved & CSA Certified Loop-Powered Meter NEMA 4X; ½" Hole Top	$309.00
PD686-Z	FM Approved & CSA Certified Loop-Powered Meter NEMA 4X; No Holes	$309.00

Accessories
Model	Description	Price
PDA6845	Zinc Plated Pipe Mounting Kit with 2 Holes	$49.00
PDA6845-SS	Stainless Steel Pipe Mounting Kit with 2 Holes	$79.00
PDA-SSTAG	Stainless Steel Tag	$25.00
PDA6844	Panel Mounting Kit for PD675, PD685, PD686 and PD697	$49.00