Precision Digital Corporation ProtEx Max Series User manual

PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
PRECISION DIGITAL CORPORATION
233 South Street • Hopkinton MA 01748 USA
Tel [phone] • Fax [phone]
www.predig.com
•Explosion-Proof Process & Temperature Meter
•4-20 mA, ± 10 V, TC & RTD Field Selectable Inputs
•Full 4-Digit Display, 1.20" (30.5 mm)
•SafeTouch Through-Glass Button Programming
•Display Mountable at 0°, 90°, 180°, & 270°
•Isolated 24 VDC @ 200 mA Transmitter Power Supply Option (AC powered meters only)
•2 Relays + Isolated 4-20 mA Output Option
•Free PC-Based MeterView Programming & Monitoring Software
•Sunlight Readable Display
•Operating Temperature Range: -40 to 65°C (-40 to 149°F)
•FM Approved as Explosion-Proof / Dust-Ignition-Proof / Flame-Proof
•CSA Certified as Explosion-Proof / Dust-Ignition-Proof / Flame-Proof
•ATEX and IECEx Certified as Flame-Proof
•Input Power Options: 85-265 VAC / 90-265 VDC or 12-36 VDC / 12-24 VAC
•Duplex Pump Controller with Alternation Capability
•External Contacts for Remote Button Operation
•On-Board RS-485 Serial Communications
•Modbus®RTU Communication Protocol Standard
•Copy Meter Settings to Other PD8-765 Meters
•Password Protection
•Max/Min Display
•High & Low Alarms with Multiple Reset Actions
•Flanges for Wall or Pipe Mounting
•Explosion-Proof, IP68, NEMA 4X Die-Cast Aluminum Enclosure
•Four 3/4" NPT Threaded Conduit Openings (Two Plugs Installed)
•Pipe Mounting Kits
•Stainless Steel Tag Available
•3-Year Warranty

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ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
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Disclaimer
The information contained in this document is
subject to change without notice. Precision Digital
makes no representations or warranties with
respectto the contents hereof and specifically
disclaims any impliedwarranties of merchantability
or fitness for a particular purpose. See Warranty
Information and Terms & Conditions on
www.predig.com for complete details.
•Read complete instructions prior to installation
and operation of the meter.
•Risk of electric shock or personal injury.
•This product is not recommended for life support
applications or applications where malfunctioning
could result in personal injury or property loss.
Anyone using this product for such applications
does so at his/her own risk. Precision Digital
Corporation shall not be held liable for damages
resulting from such improper use.
•Failure to follow installation guidelines could
result in death or serious injury. Make sure only
qualified personnel perform the installation.
•Never remove the meter cover in explosive
environments when the circuit is live.
•Cover must be fully engaged to meet
explosion-proof/dust-ignition-proof/flame-proof
requirements.
WARNING
Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Limited Warranty
Precision Digital Corporation warrants this product
against defects in material or workmanship for the
specified period under “Specifications” from the date of
shipment from the factory. Precision Digital’s liability
under this limited warranty shall not exceed the
purchasevalue,repair,orreplacementofthedefective
unit. See Warranty Information and Terms &
Conditions on www.predig.com for complete details.
Registered Trademarks
All trademarks mentioned in this document are the
property of their respective owners.
© 2022 Precision Digital Corporation.
All rights reserved.
FREE MeterView
Programming Software
Note: PD8-765 meter is not powered from USB connection
and requires external power to be programmed.
The PD8-765 is easily setup and programmed without
removing the cover by using the four through-glass
SafeTouch buttons or by removing the cover and
using the front panel push buttons. The meter can
also be programmed using a PC and Precision
Digital’s free MeterView software or “cloned” with the
Copy function. Programming the PD8-765 with
MeterView software requires removing the front cover
and connecting to the electronics module to the PC
via the PDA8006 Trident USB serial adapter.
MeterView programming software is intuitive, and
most customers can get their meter programmed as
they like without even looking in the manual.
Watch MeterView Software Video at
http://www.predig.com/meterview
In addition to programming, the software, with the use
of additional devices, may be used for:
•Monitoring
•Datalogging using your PC
•Generating and saving programming files for
later use
Once your meter is programmed the way you want it,
you can wire it up for your application per the
instructions in this manual and install it. If you find that
you need to make adjustments to the programming
after the meter is installed, you can use the
programming buttons and the instructions in this
manual to do so.
•The meter should only be connected to a
computer while it is located in a safe area.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
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Table of Contents
Introduction......................................................................................................... 7
Ordering Information.......................................................................................... 7
Helpful Videos..................................................................................................... 8
Key Features....................................................................................................... 9
Useful Tools...................................................................................................... 15
Specifications................................................................................................... 16
General .......................................................................................................... 16
Process Inputs.............................................................................................. 17
Temperature Inputs ...................................................................................... 17
Relays Option................................................................................................ 18
External Button Contacts............................................................................. 18
Isolated 4-20 mA Transmitter Output Option ............................................. 18
RS-485 Serial Communications................................................................... 18
Modbus®RTU Serial Communications....................................................... 18
Compliance Information................................................................................... 19
Electromagnetic Compatibility .................................................................... 19
EU Declaration of Conformity.......................................................................... 20
Safety Information............................................................................................ 20
Product Ratings and Approvals .................................................................. 19
Installation......................................................................................................... 20
Unpacking ..................................................................................................... 20
Mounting........................................................................................................ 21
MeterView Software...................................................................................... 23
Connections.................................................................................................. 29
Required & Factory Wired Connection........................................................ 29
PD765 Trident Electronics Module Layout................................................. 30
Connector Labeling ..................................................................................... 30
Power Connections ..................................................................................... 31
Signal Connections ..................................................................................... 31
Relays and 24 V Output Connections ......................................................... 32
Switching Inductive Loads........................................................................... 32
RS-485 Connections ................................................................................... 33
RS-485 Multi-Drop Connection.................................................................... 33
4-20 mA Output & Input Signal Connections............................................... 34
External Button Contacts............................................................................. 34
Setup and Programming.................................................................................. 35
Overview........................................................................................................ 35
LED Status Indicators................................................................................... 35
Programming Buttons.................................................................................. 36
SafeTouch Buttons....................................................................................... 36
Display Functions and Messages ............................................................... 37
Main Menu ..................................................................................................... 38
Setting Numeric Values................................................................................ 38
Setting Up the Meter (setu).......................................................................... 38
Setting the Input Signal (inpt)..................................................................... 38
Setting the Decimal Point (dc.pt) ................................................................. 39
Setting the Temperature Scale (F C)......................................................... 39
Programming the Meter (prog)..................................................................... 39
Scaling the Meter (scal).............................................................................. 39
Calibrating the Meter (Cal).......................................................................... 40
Recalibrating Temperature Inputs (Cal) ...................................................... 40
Recalibrating Process Inputs (ICal)............................................................ 40
Setting the Relay Operation (rely).............................................................. 41
Acknowledging Relays ................................................................................ 41
Relay and Alarm Operation......................................................................... 42
Scaling the 4-20 mA Analog Output (Aout).................................................. 46
Program the Sensor Break Output Value (SEbr) ........................................ 46
Analog Output when Display is Out of Range ............................................ 46
Setting Up the Password (pass)................................................................... 47
Locking the Meter........................................................................................ 47
Unlocking the Meter .................................................................................... 47

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
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Advanced Features Menu ............................................................................ 47
Advanced Features Menu & Display Messages.......................................... 47
Offset Adjustment (Adj)............................................................................... 48
Noise Filter (fltr) ....................................................................................... 48
Noise Filter Bypass (byps)........................................................................... 48
Serial Communications (serl)..................................................................... 49
Protocol Selection Menu (Prot)................................................................... 49
Select Menu (SElc)...................................................................................... 49
Linear or Square Root Function (linr or Sqrt)........................................... 49
Low-Flow Cutoff (cutF)................................................................................ 49
Display Intensity (inty) ............................................................................... 50
Meter Copy Function (Copy) ........................................................................ 50
Internal Calibration (ICal)............................................................................ 51
Meter Operation................................................................................................ 52
Buttons Operation ........................................................................................ 52
Maximum/Minimum Readings ..................................................................... 52
Remote Operation of Meter Buttons ........................................................... 52
Troubleshooting............................................................................................... 53
Diagnostics Menu (diag) .............................................................................. 53
Determining Software Version..................................................................... 53
Reset Meter to Factory Defaults.................................................................. 53
Factory Defaults & User Settings ................................................................ 54
Troubleshooting Tips................................................................................... 55
Quick Interface Reference Guide.................................................................... 57

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
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Table of Figures
Figure 1. Enclosure Dimensions –Front View................................................... 21
Figure 2. Enclosure Dimensions –Side Cross Section View ........................... 21
Figure 3: Integrated PD765 Trident Required Connections.............................. 29
Figure 4. PD765 Trident Electronics Module Layout......................................... 30
Figure 5. Connector Labeling for PD8-765-6X0-10 ............................................ 30
Figure 6. Connector Labeling for PD8-765-6X3-20 ............................................ 30
Figure 7. Connector Labeling for PD8-765-7X0-00 ............................................ 30
Figure 8. Connector Labeling for PD8-765-7X5-00 ............................................ 30
Figure 9. Power Connections.............................................................................. 31
Figure 10. Transmitter Powered by Internal Supply.......................................... 31
Figure 11. Transmitter Powered by External Supply or Self-Powered............. 31
Figure 12. Voltage Input Connections ................................................................ 31
Figure 13. Thermocouple Input Connections..................................................... 31
Figure 14. Three-Wire RTD Input Connections.................................................. 31
Figure 15. Two-Wire RTD Input Connections..................................................... 32
Figure 16. Four-Wire RTD Input Connections.................................................... 32
Figure 17. Relay & 24 V Output Connections..................................................... 32
Figure 18. AC and DC Loads Protection............................................................. 32
Figure 19. Low Voltage DC Loads Protection.................................................... 32
Figure 20. RS-485 Connections........................................................................... 33
Figure 21. Three-Wire RS-485 Connections....................................................... 33
Figure 22. 4-20 mA Output & Input Signal Powered by PD8-765-6X3-20........ 34
Figure 23. 4-20 mA Output Signal Powered by PD8-765-6X5-10 ..................... 34
Figure 24. 4-20 mA Output Powered Externally................................................. 34
Figure 25. PD8-765-6X5-10 Powers Both the Heater Input Signal.................... 34

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
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Introduction
The ProtEX-MAX PD8-765 explosion-proof,
large-display, process and temperature meter offers
all the functionality of the PD765 Trident as a fully FM,
CSA, ATEX, and IECEx approved explosion-proof
product. PD8-765's huge 1.2" (30.5 mm) sunlight
readable display is visible from over 30 feet away.
This explosion-proof indicator can be field
programmed to accept process voltage (0-5 V, 1-5 V,
etc.) and current (4-20 mA) inputs, 100 Ohm RTDs,
and the four most common thermocouples.
The intensity of the display can be adjusted to
compensate for various lighting conditions, including
direct sunlight. The meter can be programmed and
operated without opening the housing by using the
built-in SafeTouch through-glass buttons or the
RS-485 serial communication port with free Modbus®
protocol. Options for the PD8-765 process and
temperature indicator include 2 relays, a 4-20 mA
output, and a 24 V transmitter power supply.
SafeTouch Buttons
To make it possible to program and operate the
ProtEX-MAX in a hazardous area, the programming
buttons that are located behind the glass window can
be operated without removing the cover by using the
SafeTouch through-glass buttons. The operator puts
their finger on the glass over the button and the
button is actuated.
To learn more about SafeTouch buttons,
see this video:
predig.com/videos/Safetouch_Buttons
Ordering Information
85-265 VAC Models
Model
Options Installed
PD8-765-6X0-10
24 VDC Transmitter Supply
PD8-765-6X3-20
4-20 mA Out
Dual 24 VDC Transmitter Supplies
PD8-765-6X5-10
2 Relays
4-20 mA Output
24 VDC Transmitter Supply
12-36 VDC Models
Model
Options Installed
PD8-765-7X0-00
No options
PD8-765-7X5-00
2 relays
4-20 mA output
Accessories
Model
Description
PDA7420
PD8-765 Copy Cable, 7' (2.1 m)
PDA8006*
USB Serial Adapter for Programming
Meter with MeterView Software
PDAPLUG75
3/4" Metal Conduit/Stopping Plug
PDA-SSTAG
Custom Stainless Steel Tag (see
website for convenient ordering form)
PDA6848
2" U-Bolt Kit Zinc Plated Steel
PDA6848-SS
2" U-Bolt Kit Stainless Steel
*See Free 8006 to receive PDA8006 at no charge.
Notes:
1. 24 VDC transmitter supply available only on
AC powered meters.
2. RS-485 Communications is standard on all
products

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
8
Helpful Videos
There are several videos that will help you get a
better understating of the features and functionality of
the ProtEX-MAX products. Since the PD8-765 meters
have the same general features and functionality of
the PD765 Trident meters, appropriate videos for the
PD765 Trident meter are also included.
ProtEX-MAX Products Overview
Learn about the complete line of ProtEX-MAX products.
predig.com/videos/ProtEXMAX_Overview
Programming a Thermocouple Input
This video details how to program a thermocouple
input on a PD765 Trident Series meter.
predig.com/Program_Trident_Thermocouple
PD765 Trident Display Advantages
The PD765 Trident digital panel meter's 1.2" LED
display makes it the ideal choice when upgrading your
panels. Watch this video and see real examples of the
PD765 Trident improving existing panels with its huge
display!
predig.com/videos/Trident_X2_Display_Advantages
PD765 Trident Demonstration
Watch this live demonstration of the PD765 Trident
digital panel meter and see how it can improve your
process. This video will show you the advantage of
the large 1.2" display and simulate a level application.
predig.com/videos/Trident_X2_Live_Demo
MeterView Serial Communications
The PD765 Trident series is one of Precision Digital's
most trusted and proven meters ever, and it now has
new serial communications capabilities to make it
easier to use than ever before. Watch this short video
for more information.
predig.com/MV_Serial_Comm_PDA8006
Use ProtEX-MAX for Pump Control
Learn how to use the PD765 Trident (ProtEX-MAX)
meter as an explosion-proof pump controller. See
how two relays can be used to control two pumps with
alternation capability.
predig.com/videos/Pump_Controller_Key_Features

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
9
Key Features
The Only Explosion-Proof Process & Temperature Meter You Will Ever Need
The PD8-765 ProtEX-MAX is an explosion-proof
version of the popular PD765 Trident process and
temperature meter. It can satisfy a wide variety of
process applications. The PD8-765 can be field
programmed to accept process voltage (0-5V, 1-5V,
etc.) and current (4-20 mA) inputs, 100 Ohm RTDs,
and the four most common thermocouples. It is
housed in an IP68 NEMA 4X rated explosion-proof
die cast aluminum enclosure and is a fully approved
product carrying FM, CSA, ATEX, and IECEx
approvals.
There are two power options for the ProtEX-MAX:
85 to 265 VAC or 12-36 VDC and the AC powered
versions can provide 24 VDC to power the transmitter
if needed. Programming and setup can be performed
with the four SafeTouch through-glass buttons, free
MeterView software, or using the Copy function.
The relays and isolated 4-20 mA output option
increases the utility of the PD8-765. The relays can be
used for alarm or control applications. The 4-20 mA
output provides an isolated retransmission of the input
signal; especially useful for temperature inputs like
thermocouples and RTDs. Now you can have an
explosion-proof temperature transmitter with a huge,
bright display!
The PD8-765 ProtEX-MAX display height is an
astounding 1.2" (30.5 mm). It can be read easily from
distances of up to 30 feet away! The display intensity
function allows the selection of eight levels of intensity
for various lighting conditions, including direct
sunlight.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
10
Easy Programming Methods
The PD8-765 is easily setup and programmed without
removing the cover by using the four through-glass
SafeTouch buttons or by removing the cover and
using the front panel push buttons. The meter can
also be programmed using a PC and Precision
Digital’s free MeterView software or “cloned” with the
Copy function. Programming the PD8-765 with
MeterView software requires removing the front cover
and connecting to the electronics module to the PC
via the PDA8006 Trident USB serial adapter.
MeterView software allows all PD8-765 setup
parameters to be programmed from a PC and to save
the configuration settings to a file for reporting or
programming other meters. For programming
purposes, MeterView software connects to the
PD8-765 meter via the low-cost PDA8006 USB serial
adapter pictured above. We will even send you a
PDA8006 USB adapter, normally sold for $43.00, at
no cost if you register your meter at
http://www.predig.com/free8006 (limit one per
customer). You can program the PD8-765 you just
bought with the front panel buttons and have the
PDA8006 on hand for programming future meters.
Advanced Display Features
Super-Bright Display
The ProtEX-MAX comes standard with a super-bright
display, with LEDs that are visible even in direct
sunlight. The display also has up to eight levels of
adjustable intensity for optimum visibility in any
lighting condition.
Four Full Digits
The display on the PD8-765 is four full digits which
means it can display numbers up to 9999. Many digital
devices have displays of only 3½ digits which means
they can display only to 1999. In practical terms, this
means the PD8-765 can display type K thermocouples
to 2300ºF and 4-20 mA signals up to 9,999.
Front Panel LEDs
The meter is supplied with two alarm points that
include front panel LEDs to indicate alarm conditions.
This standard feature is particularly useful for alarm
applications that require visual-only indication.
Large Display Size
The display height on the ProtEX-MAX PD8-765 is an
astounding 1.2" (30.5 mm). It can be easily read from
distances of up to 30 feet!
Meter Copy
The Copy function is used to copy (or clone) all the
settings from one PD8-765 meter to other PD8-765
meters in less than 10 seconds. The Copy feature
does not require a serial communication adapter, it
only requires the optional cable assembly (PDA7420).
Note: The PD8-765 modules must be removed from the enclosures
to connect the copy cable.
Display & Toggle Max / Min Reading
The main function of the front panel buttons during
operation is to display the maximum and minimum
readings reached by the process or temperature
inputs. The PD8-765 allows you to toggle between the
maximum and minimum readings of the process
values. To display the maximum and minimum
readings since the last reset/power-up, use the
Up arrow/Max button.
Display & Toggle Maximum Value
Display & Toggle Minimum Value
ProtEX-MAX PD8-765
Actual Size Digit
1.2"
(30.5 mm)

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
11
Physical Features
The ProtEX-MAX is designed for ease-of-use in safe
and hazardous applications. The ProtEX-MAX is
housed in a rugged NEMA 4X explosion-proof
enclosure, can operate over a wide temperature
range, includes removable screw terminal connectors,
has worldwide approvals for use in hazardous areas,
and features through-glass buttons for easy meter
operation without the need to remove the cover.
All of these features are backed by a 3-year warranty.
Super-Bright LED Display
The ProtEX-MAX features a 4-digit display with
super-bright LEDs, our brightest ever. These allow the
display to be read in any lighting condition, even in
direct sunlight.
SafeTouch Through-Glass Buttons
The ProtEX-MAX is equipped with four sensors that
operate as through-glass buttons so that it can be
programmed and operated without removing the
cover (and exposing the electronics) in a hazardous
area. These buttons can be disabled for security by
selecting the DISABLE setting on the NO-CONTACT
BUTTONS switch located on the back of the
electronics module, inside the enclosure.
Rugged, Heavy-Duty Enclosure
The ProtEX-MAX is housed in a rugged NEMA 4X, 7,
& 9, IP68 die-cast aluminum enclosure, designed to
withstand harsh environments in safe and hazardous
areas over a wide temperature range.
Wide Viewing Angle
Customers can’t always look at the display from
straight on, so the window and display module have
been optimized to provide a wide viewing angle of
approximately ± 40°; nearly twice that of the
competition.
Built-In Mounting Flanges
The ProtEX-MAX is equipped with four slotted flanges
for wall mounting or NPS 1½" to 2½" or DN 40 to 65
mm pipe mounting.
Flexible Mounting & Wiring
The ProtEX-MAX features four ¾" NPT threaded
conduit openings so that wiring can be routed to the
most convenient conduit connection(s). Two ¾" NPT
metal conduit plugs with 12 mm hex key fitting come
installed.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
12
Rotatable Display
The ProtEX-MAX rotatable display, along with four
available conduit connections, provide for numerous
installation options. The display can be rotated in 90°
increments. Rotate it 90° for horizontal mounting.
Vertical Mounting Horizontal Mounting
Perfect & Secure Fit Every Time
The internal cast rails ensure the ProtEX-MAX
assembles together perfectly, quickly and securely;
and everything lines up for optimal viewing every
time. There are no standoffs to worry about breaking
or getting out of alignment. Two spring-loaded,
self-retaining, thumbscrews make the assembly a
snap, while pressing the display as close to the glass
as possible to improve wide angle viewing.
Stainless Steel Tags
PDA-SSTAG is a laser etched stainless steel tag
accessory for any of your Precision Digital meters.
The tag features custom text for equipment
identification, instruction, or whatever else is needed
in your facility. Each tag comes with a stainless steel
wire and lead seal for easy mounting wherever you
need it.
Removable Screw Terminals
Industrial applications require screw terminal
connections for easy field wiring and the ProtEX-MAX
goes one step further in convenience by also making
them removable.
Note: The terminals on the External Contacts connector
are wired to the connector on the electronics module
to enable the SafeTouch buttons so the meter can be
programmed without removing the cover.
Program Meter from USB Port
Hazardous Area Approvals
The ProtEX-MAX's approvals allow it to be used in
hazardous areas around the world. These include:
FM Approved as Explosion-Proof / Dust-Ignition-Proof /
Flame-Proof, CSA Certified as Explosion-Proof /
Dust-Ignition-Proof, and ATEX and IECEx Certified as
Flame-Proof.
Wide Operating Temperature Range
The ProtEX-MAX can operate from -40 to 60°C
(-40 to 140°F) meaning it can be installed in a wide
variety of indoor and outdoor industrial applications.
Use the PDA8006 Trident
USB Serial Adapter for
Programming with MeterView
Easy Plug-in Removable
Terminal Connectors

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
13
Transmitter Power Supplies
Meter Powers Transmitter
One of the most useful features of AC powered
PD8-765s is their built-in, isolated, 24 V @ 200 mA
power supply to power the transmitter. This feature
saves money by eliminating an external power supply
and also simplifies wiring.
The following diagrams illustrate how to wire an AC
powered PD8-765 so it will power the transmitter:
Connections for PD8-765-6X0-10 & PD8-765-6X5-10
Meter Powers 4-20 mA Output
Not only can the AC powered PD8-765 power the
4-20 mA input signal, but an additional power supply
of 24 V @ 40 mA is available to power the 4-20 mA
output.
Connections for PD8-765-6X3-20
Isolated Transmitter Output
The PD8-765's isolated 4-20 mA output option
converts the meter into a transmitter / loop isolator
with a digital display; perfect for temperature
applications!
Fuse Prevents Current Overload
Another very useful aspect of the PD8-765 is that the
current input is protected against current overload by
a resettable fuse. The fuse limits the current to a safe
level when it detects a fault condition, and
automatically resets itself when the fault condition is
removed.
Other Uses for Power Supplies
The most common use for these two power supplies
is for the 200 mA transmitter power supply to power
the field transmitter and 40 mA power supply to power
the 4-20 mA output from the meter. However, these
two power supplies can be used in other ways. For
instance, some level transmitters require the use of a
heated lens. The PD8-765’s 200 mA power supply
could be used to power both the heated lens and the
4-20 mA signal from the transmitter.
PD8-765-6X5-10 Powers Both the Heater
and 4-20 mA Input Signal
External Power Supply for Loop
For applications that require an external transmitter
power supply, the same PD8-765 is used and merely
wired in a different fashion as the following diagrams
illustrate:

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
14
Exp-Proof Temperature
Transmitter with Big Display
The PD8-765, with an optional 4-20 mA output, can
be used as an isolated temperature transmitter with a
big display by converting the thermocouple or RTD
input into an isolated 4-20 mA output.
Input Signal Conditioning
To satisfy applications that require scaling in ways
other than the usual 2-point linear method, the
ProtEX-MAX can also be scaled for square root
(DP flow).
Square Root Linearization
The square root function can be used to linearize the
signal from a differential pressure transmitter and
display flow rate in engineering units.
Exp-Proof Dual-Pump Alternation
The ProtEX-MAX can be used as an explosion-proof
pump controller when combined with a continuous
level transmitter. The most common pump control
application is shown below: controlling and alternating
two pumps. In addition, the ProtEX-MAX provides the
24 V to power the transmitter.
Relay #1 turns the main pump on at 6000 gallons and
turns it off at 1000 gallons.
With the Pump Alternation feature activated, the next
time the level reaches 6000 gallons, relay #2 starts
the backup pump.
If the active pump is not able to keep up, and the level
reaches 7000 gallons, the other relay will start the
inactive pump as well.
When the level falls below 1000 gallons, both pumps
will turn off.
Learn how to use the PD765 Trident
(ProtEX-MAX) meter as an explosion-proof
pump controller. See how the four relays
can be used to alternate two pumps and
provide high and low alarms.
predig.com/videos/PumpControl

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
15
Useful Tools
PD9501 Multi-Function Calibrator
This PD9501 Multi-Function Calibrator has a variety
of signal measurement and output functions, including
voltage, current, thermocouple, and RTD.
PD9502 Low-Cost Signal
Generator
The PD9502 is a low-cost, compact, simple to use
4-20 mA or 0-10 VDC signal generator. It can easily
be set for 0-20 mA, 4-20 mA, 0-10 V or 2-10 V
ranges. Signal adjustment is made with a one-turn
knob. A 15-27 VDC wall plug is provided with the
instrument. Optional USB power bank is available.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
16
Specifications
Except where noted all specifications apply to
operation at +25°C.
General
Display
1.20" (31 mm), red LED,
Four digits (-1999 to 9999),
automatic lead zero blanking.
Display
Intensity
Eight user selectable intensity levels.
Default intensity is six.
Display
Update Rate
Process/RTD: 3.7-5/second
Thermocouple: 1.8-2.5/second
LED Status
Indicators
See LED Status Indicators on page 35
for details.
Overrange
Display flashes 9999
Underrange
Display flashes -1999
Programming
Methods
Four SafeTouch through-glass buttons
when cover is installed. Mechanical
buttons can be used with the cover
removed. Cloning with Copy feature.
Free PC-based USB MeterView
programming software, and Modbus®
registers.
Noise Filter
Programmable from 2 to 199
(0 will disable filter)
Filter Bypass
Programmable from 0.1 to 99.9% of
calibrated span
Recalibration
All ranges are calibrated at the factory.
Recalibration is recommended at least
every 12 months.
Max/Min
Display
Max/min readings reached by the process
are stored until reset by the user or until
power to the meter is turned off.
Password
Restricts modification of programmed
settings
Non-Volatile
Memory
All programmed settings are stored in
non-volatile memory for a minimum of ten
years if power is lost.
Power
Options
85-265VAC,50/60Hz;90-265VDC,20Wmax
or 12-36 VDC; 12-24 VAC, 6 W max
Fuse
Required external fuse: UL Recognized,
5 A max, slow blow; up to 6 meters may
share one 5 A fuse
Normal Mode
Rejection
64 dB at 50/60 Hz
Isolation
4 kV input/output-to-power line
500 V input-to-output
or output-to-P+ supply
6X5 models only:
100 V output-to-24 VDC supply
Overvoltage
Category
Installation Overvoltage Category II:
Local level with smaller transient
overvoltages than Installation Overvoltage
Category III
Environmental
T6 Class operating temperature range
Ta = -40 to 60°C
T5 Class operating temperature range
Ta = -40 to 65°C
Storage temperature range:
-40 to 85°C (-40 to 185°F)
Relative humidity:
0 to 90% non-condensing
Connections
Power, signal, relays, mA out: Removable
screw terminal blocks accept 12 to 22
AWG wire
RS-485: Removable screw terminal block
accepts 16 to 30 AWG wire
Enclosure
Explosion-proof die cast aluminum with
glass window, corrosion resistant epoxy
coating, color: blue
NEMA 4X, 7, & 9, IP68
Default conduit connections: Four ¾" NPT
threaded conduit openings and two ¾"
NPT metal conduit plugs with 12 mm hex
key fitting installed. Additional conduit
opening configurations may be available;
verify quantity and sizes on specific device
labeling during installation.
Mounting
Wall Mounting:
Four (4) mounting holes provided for
mounting meter to wall. See Wall
Mounting Instructions on page 21 for
additional details.
Pipe Mounting:
Optional pipe mounting kit (PDA6848)
allows for pipe mounting. Sold separately.
See Pipe Mounting Instructions on page
22 for additional details.
Tightening
Torque
Screw terminal connectors:
5 lb-in (0.56 Nm)
Overall
Dimensions
6.42" x 7.97" x 8.47" (W X H X D)
(163 mm x 202 mm x 215 mm)
Weight
16.0 lbs (7.26 kg)
Warranty
3 years parts & labor. See Warranty
Information and Terms & Conditions on
www.predig.com for complete details.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
17
Process Inputs
Inputs
0-20 mA, 4-20 mA, 1-5 V, ±10 V
Transmitter
Supply
Isolated, one or two transmitter
supplies P1: 24 VDC ±10% @ 200 mA
max (-10 option) P1 & P2: 24 VDC
±10% @ 200 mA & 40 mA max
(-20 option)
Accuracy
±0.05% FS ±1 count;
±0.1% FS ±2 counts for square root
Function
Linear or square root
Low-Flow
Cutoff
0 to 9999 (0 disables cutoff function)
Point below at which display always
shows zero
Decimal Point
Up to 3 decimals
Calibration
Scale without signal or calibrate with
signal source
Calibration
Range
User programmable over entire range
of meter
Input
Impedance
Voltage range: greater than 1 MΩ,
Current range: 50-100 Ω, varies with
resettable fuse impedance
Input
Overload
Protected by automatically resettable
fuse
HART
Transparency
The meter does not interfere with
existing HART communications; it
displays the 4-20 mA primary variable
and it allows the HART communications
to pass through without interruption.
The meter is not affected if a HART
communicator is connected to the loop.
The meter does not display secondary
HART variables.
Temperature Drift
0 to 65C
ambient
-40 to 0C
ambient
Current: ±0.20% FS
(50 PPM/C)
Voltage: ±0.02% FS
(1.7 PPM/C)
Current:
±0.80% FS
Voltage:
±0.06% FS
Temperature Inputs
Inputs
Factory calibrated, field selectable:
type J, K, T, or E thermocouples and
100 Ω platinum RTD (0.00385 or
0.00392 curve)
Resolution
1°; type T TC & RTD: 1° or 0.1°
Cold Junction
Reference
Automatic
Temperature Drift
±2°C maximum
Offset
Adjustment
Programmable to ±19.9°. This
parameter allows the user to apply an
offset value to the temperature being
displayed.
Input
Impedance
Greater than 100 k
Accuracy
Input Type
Range
Accuracy
(0 - 65 C)
Accuracy
(-40 - 0 C)
Resolution
J
-58 to 1382F
-50 to 750C
±2°F
±1°C
±5°F
±3°C
1°
K
-58 to 2300F
-50 to 1260C
±2°F
±1°C
±4°F
±2°C
1°
T
-292 to 700F
-180 to 371C
±2°F
±1°C
±13°F
±7°C
1° or 0.1°
E
-58 to 1700ºF
-50 to 927ºC
±2°F
±1°C
±11°F
±6°C
1°
RTD
-328 to 1382F
-200 to 750C
±1°F
±1°C
±5°F
±3°C
1° or 0.1°

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
18
Relays Option
Rating
2 Form C (SPDT); rated 3 A @ 30 VDC
or 3 A @ 250 VAC resistive load;
1/14 HP (≈ 50 watts) @ 125/250 VAC
for inductive loads such as contactors,
solenoids, etc.
Deadband
0-100% FS, user selectable
Electrical Noise
Suppression
A snubber should be connected to
each relay contact switching inductive
loads to prevent disruption to the
microprocessor’s operation.
Recommended snubber value:
0.01 µF/470 , 250 VAC (PDX6901).
High or Low
Alarm
User may program any alarm for high
or low
Relay
Operation
•Automatic (non-latching) and/or
manual reset
•Latching (requires manual
acknowledge) with/without clear
•Pump alternation control
•Off (disable unused relays)
Relay Reset
Front panel button, terminal at back of
meter or through serial communications
Time Delay
0 to 199 seconds, on and off delays;
programmable
Sensor Break
Relay Operation
The sensor break relay condition may
be programmed for each relay as
On (alarm) or Off (non-alarm).
The relays will enter these states when
a sensor break is detected for RTD or
thermocouple inputs. These settings
have no effect when current or voltage
inputs are selected.
Fail-Safe
Operation
Programmable, independent for each
relay. Relay coils are energized in
non-alarm condition. In case of power
failure, relays will go to alarm state.
Auto
Initialization
When power is applied to the meter,
relays will reflect the state of the input
to the meter.
External Button Contacts
Number
Four
Function
Remote operation of front-panel
buttons: programming, reset relays or
view/reset max/min readings
Open State
+5 VDC open contact on button input
terminals
Closed State
Closed contact button input terminal to
common/ground, active low 0 to 0.4 VDC
Isolated 4-20 mA Transmitter
Output Option
Scaling Range
1.00 to 23.00 mA;
reverse scaling allowed
Calibration
Factory calibrated for 4-20 mA
Accuracy
±0.1% FS ±0.004 mA
Temperature Drift
50 PPM/°C
Note: Analog output drift is separate from
input drift.
Isolation
500 V input-to-output or output-to-24
VDC supplies
4 kV output-to-power line
For -6X5 models only:
100 V output-to-24 VDC supply
External Power
35 VDC maximum
Output Loop
Resistance
Power
supply
Minimum
Maximum
24 VDC
10 
700 
35 VDC
(external)
100 
1200 
RS-485 Serial Communications
Compatibility
EIA-485
Connectors
Removable screw terminal connector
Max Distance
3,937' (1,200 m) max
Status Indication
Separate LEDs for Transmit (TX) and
Receive (RX)
Modbus®RTU Serial
Communications
Slave Id
1 –247 (Meter address)
Baud Rate
300 –19,200 bps
Transmit
Time Delay
Programmable between 0 and 199 ms
Data
8 bit (1 start bit, 1 stop bit)
Parity
None (1 or 2 stop bits), even, or odd
(Modbus®only; PDC protocol does not
use parity)
Byte-To-Byte
Timeout
0.01 –2.54 second
Turn Around
Delay
Less than 2 ms (fixed)
Note: Refer to the ProtEX-MAX Modbus®Register Tables located at
www.predig.com for details.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
19
Compliance Information
Electromagnetic Compatibility
Emissions
EN 55011
Group 1 Class A ISM emissions
requirements
Radiated
Emissions
Class A
AC Mains
Conducted
Emissions
Class A
Immunity
EN 61326-1
Measurement, control, and laboratory
equipment
EN 61000-6-2
EMC heavy industrial generic immunity
standard
RFI -
Amplitude
Modulated
80 -1000 MHz 10 V/m 80% AM (1 kHz)
1.4 - 2.0 GHz 3 V/m 80% AM (1 kHz)
2.0 - 2.7 GHz 1 V/m 80% AM (1 kHz)
Electrical Fast
Transients
±2kV AC mains, ±1kV other
Electrostatic
Discharge
±4kV contact, ±8kV air
RFI -
Conducted
10V, 0.15-80 MHz, 1kHz 80% AM
AC Surge
±2kV Common, ±1kV Differential
Surge
1KV (CM)
Power-
Frequency
Magnetic Field
30 A/m 70%V for 0.5 period
Voltage Dips
40%V for 5 & 50 periods
70%V for 25 periods
Voltage
Interruptions
<5%V for 250 periods
Product Ratings and Approvals
FM
Enclosure: Type 4X; IP66
Class I, Division 1, Groups B, C, D
Class II, Division 1, Groups E, F, G
Class III, Division 1, T5/T6
Class I, Zone 1, AEx d, IIC Gb T5/T6
Zone 21, AEx tb IIIC T90°C; Ta -40°C to +65°C
T6 Ta = -40°C to +60°C; T5 Ta = -40°C to +65°C
Certificate Number: 3047283
CSA
Class I, Division 1, Groups B, C, D
Class II, Division 1, Groups E, F, G
Class III, Division 1
Class I Zone 1 Ex d IIC
Zone 21 Ex tb IIIC T90°C
-40°C < Tamb. < +60° C; Temperature Code T6
-40°C < Tamb. < +65° C; Temperature Code T5
Enclosure Type 4X & IP66
Certificate Number: 2531731
ATEX
II 2 G D
Ex d IIC T* Gb
Ex tb IIIC T90°C Db IP68
Ta = -40°C to +*°C
*T6 = -40°C to +60°C
*T5 = -40°C to +65°C
Certificate number: Sira 12ATEX1182
IECEx
Ex d IIC T* Gb
Ex tb IIIC T90°C Db IP68
Ta = -40°C to +*°C
*T6 = -40°C to +60°C
*T5 = -40°C to +65°C
Certificate Number: IECEx SIR 12.0073
Special Conditions for Safe Use:
Use suitably certified and dimensioned cable entry
device and/or plug. The equipment shall be installed
such that the supply cable is protected from mechani-
cal damage. The cable shall not be subjected to ten-
sion or torque. If the cable is to be terminated within
an explosive atmosphere, then appropriate protection
of the free end of the cable shall be provided. Cable
must be suitable for 90°C.
Year of Construction
This information is contained within the serial number
with the first four digits representing the year and
month in the YYMM format.
For European Community: The ProtEX-MAX must
be installed in accordance with the ATEX directive
94/9/EC, and the product certificate Sira
12ATEX1182.

ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
20
EU Declaration of Conformity
EU Declaration of Conformity is available in the
Documentation CD provided with the product under
the EU DoC menu.
Safety Information
•Read complete instructions prior to installation
and operation of the meter.
•Risk of electric shock or personal injury.
•Hazardous voltages exist within enclosure.
Installation and service should be performed only
by trained service personnel.
Installation
Install in accordance with applicable local and
national regulations (e.g. NEC).
For Installation in USA
The ProtEX-MAX must be installed in accordance
with the National Electrical Code (NEC) NFPA
70.
For Installation in Canada
The ProtEX-MAX must be installed in accordance
with the Canadian Electrical Code CSA 22.1. All
power supplies below 36 V and input circuits
must be derived from a CSA Approved Class 2
source.
For European Community
The ProtEX-MAX must be installed in accordance
with the ATEX directive 94/9/EC and the product
certificate Sira 12ATEX1182.
•Disconnect from supply before opening
enclosure.
•Keep cover tight while circuits are live.
•Conduit seals must be installed within 18"
(450mm) of the enclosure or within 2" (50mm)
for Zone installations.
Wiring connectors are accessed by opening the
enclosure. To access electrical connectors,
remove the 2 captive screws and then remove
the electronics module. Connectors are on the
rear of the electronics module.
Unpacking
Remove the meter from box. Inspect the
packaging and contents for damage. Report
damages, if any, to the carrier.
If any part is missing or the meter malfunctions,
please contact your supplier or the factory for
assistance.
Pre-Installed Conduit Plugs
The ProtEX-MAX is supplied with two pre-installed
conduit plugs for installations that do not require the
use of all four conduit entries. The conduit/stopping
plugs include an internal hexagonal socket recess for
removal. The conduit plugs and their factory
installation are included in all hazardous area
approvals of this product.
•In hazardous areas, conduit and conduit/stopping
plugs require the application of non-setting
(solvent free) thread sealant. It is critical that all
relevant hazardous area guidelines be followed
for the installation or replacement of conduit or
plugs.
Cover Jam Screw
The cover jam screw should be properly installed
once the meter has been wired and tested in a safe
environment. The cover jam screw is intended to
prevent the removal of the meter cover in a
hazardous environment without the use of tools.
Using a M2 hex wrench, turn the screw clockwise until
the screw contacts the meter. Turn the screw an
additional 1/4 to 1/2 turn to secure the cover.
•Excess torque may damage the threads and/or
wrench.