Precision Digital PD686 - Manual (Page 2)

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Precision Digital corPoration
89 October Hill Rd • Holliston MA 01746 USA • Tel (800) 343-1001 • Fax (508) 655-8990
LDS686_E 06/09
Model Pd686 3½ digit NeMA 4X looP-PoWeRed MeteR
SIDE VIEW
Wall
Mounting
Holes
Beneath
Cover
Screws
E
F
FRONT VIEW
D
A C
B
Figure 4
Dimensions and Wall Mounting Information
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)
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+
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
HAZARDOUS AREA NON-HAZARDOUS AREA
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-
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
Note: To maintain hazardous area protection, the input signal must always be connected to the Input Signal PCB, and not directly to the Display PCB.
Warning: Electrostatic hazard. Clean only with a moist cloth. Protect enclosure from exposure to chemical solvents and excessive ultraviolet (UV) light (e.g. sunlight).
Note 1: If any of the following operations are performed in the
hazardous area, all appropriate hazardous area procedures must be
followed.
Note 2: to prevent damage to electronic components caused by
electrostatic discharge, a grounding strap should be worn when
servicing the display.
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.
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 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 (see Figure 4).
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, as shown in Figure 1.
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.
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.
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.
©2009 Precision Digital Corporation. All rights reserved.