Hofmann DPH-64 Manuale utente
DIGITAL
pH/mV
CONTROLLER
DPH-64
USERS GUIDE
DPH-64 Instruction manual PAGE 1
TABLE OF CONTENTS
SPECIFICATIONS ................ 3
INTRODUCTION ................. 5
INSTALLATION ................. 8
Instrument ................... 8
Wiring of the DPH-64 ............. 9
Electrodes ................... 9
Starting up the Instrument. .......... 9
CONFIGURATION ................ 10
Default values for the DPH-64 instrument . . 10
Configurations for the DPH-64. ........ 11
Calibrating pH or mV ............. 11
Setting Time and Day ............. 12
Calibrating 4mA and 20mA with a multimeter. 12
Changing mode of operation. ......... 14
Extended Features .............. 16
Timed relays .................. 17
S1 relay used as a TIMER .......... 18
S2 as ALARM RELAY. ............ 18
S3 / S4 with DELAY .............. 18
S3 / S4 Proportional .............. 19
S3 / S4 Temperature ............. 19
4-20mA SETPOINT .............. 20
P1 / P2 Pulse output. ............. 21
Reset to Defaults ............... 22
WIRING GUIDE ................. 23
PAGE 2 DPH-64 Instruction manual
SPECIFICATIONS
Range: 0-14pH 0.01 pH resolution
+1000mV 1mV resolution
Display: Dot matrix 4 line by 20 character backlid LCD display
Electrode: BNC external of housing.
Temperature: (pH only) manual or automatic temp. Compensation
0-100 oC.
Signal output: 4-20mA, electrically isolated from instrument.
4-20mA range software selected between 0 to 14pH
or 0 to +1000mV. Maximum termination impedance to
drive 20mA is 1000 Ohms.
Can also be setup to follow setpoint for signal driven
metering pumps.
Relay outputs: 2 relays (S1 & S2) switched active with neutral and
earth terminals. Contacts rated 240V 5AMPS
(non-inductive)
2 relays (S3 & S4) with potential free changeover
contacts. Timers can be activated to enable / disable
relay outputs for programmed times.
Set points: All relays can be configured for up/down dosing.
Enable a Time delay of 1 to 5 minutes between
S3 & S4 if acid / alkaline dosing is required.
DPH-64 Instruction manual PAGE 3
Clock: Real time clock with AM/PM or 24H mode. Battery
backed up.
Additional
relay functions: S1 can be set up as a timer with real time
ON/OFF timing.
S3 and S4 can operate in proportional mode.
S3 and S4 can also be lprogrammed to track
temperature for temperature control or alarm.
S2 configurable as a high/low alarm.
Pulse output: P1 and P2 are (contact closure) non-polarised pulsed
outputs. Minimum pulse duration 250mS. 500 volt
isolation to instrument output. Maximum voltage
across terminals 100 volts.
Pulse rate: Select maximum pulse rate per minute from 50 to 100
pulses. Slope of pulse frequency 0.5pH to 2pH
above/below SET POINT.
Power supply: 240V/50H 8VA max.
Construction: Fully sealed construction with hinged clear acrylic
front cover. IP55 specifications.
Dimensions: (W)215mm x (H)185mm x (D)115mm.
PAGE 4 DPH-64 Instruction manual
INTRODUCTION
The 4 line by 20-character LCD display allows text messages or
prompts in “real” language without confusing abbreviations.
Encoder knobs are rotated to scroll through different menus, values or
changing set points. Once a mode of operation, calibration value or
setpoint is dialled simply push the encoder knob to select. All custom
configurations are stored in non-volatile memory.
A real time clock is always present and each relay output can be linked
with a timer to operate only at programmed times.
The signal generated from a pH electrode is extremely weak with a very
high impedance and therefore very sensitive to electrical interference.
This necessitates the use of shielded cable for the connection of the
electrode. A coaxial cable with an additional outer layer of carbon must
be used to ensure a steady pH signal. The DPH-64 converts the electrode
signal with a precision input amplifier and then further processes the
electrical signal for display, alarm, signal and set point controls.
.1/
DPH-64 pH / ORP controller
DPH-64 Instruction manual PAGE 5
The DPH-64 features 6 relay outputs with a multitude of configurations
possible to make this instrument suitable for almost every installation
where pH, ORP, temperature control or timer output is required. Default
label names for these outputs are S1, S2, S3, S4 and P1, P2. The DPH-64
is shipped with its basic setup of all four relays set point controlled for up
or down dosing. All other features are ‘hidden’ when scrolling through the
software setup. The appropriate setup window only appears once a
feature is enabled. Scrolling through a setup is therefore much easier to
follow.
Extended features possible are:
All relays linked with the real time clock to operate only at programmed
times.
S1 operating as timer output starting in real time and selected duration.
(biocide dosing etc.)
S2 used as an alarm with separate programmable high, low alarm set
points.
Time delay between S3 & S4 to avoid overshoot when dosing acid and
alkaline simultaneously
S3 and S4 used in proportional mode with adjustable gradient of
pulsing.
S3 and S4 linked to temperature with programmable temperature
setpoint and deadband.
The 4-20mA current output configured for set point control. Used with
a current signal controlled pump.
P1 and P2 are used with dosing pumps requiring a trigger pulse input.
Additional features
Temperature compensation is set for 20oC by default. This can be
changed in the configuration program from 0 to 100oC.
A TP150 temperature electrode connected to the terminals enables
the option for automatic compensation.
PAGE 6 DPH-64 Instruction manual
The inherent accuracy and range configuration of the 4-20mA constant
current output together with full electrical isolation make it possible to
interface into a microprocessor, logic controller or data logger to further
expand the combination of installations with the DPH-64.
An “activity indicator” in the top right corner of the LCD display continu-
ously averages the electrode input and displays an increase, decrease or
steady pH / mV. This is handy as it enables an operator to see instantly
if a dosing cycle is changing the pH or mV in a system.
All setpoints, modes and calibration values are stored separately for pH
and mV therefore a complete configuration for each mode is possible and
is saved in memory. Switching from pH to mV or visa versa will therefore
instantly return a previous setup.
.1/
Subpanel and terminal layout..
DPH-64 Instruction manual PAGE 7
INSTALLATION
Instrument
Select a position for the controller to be mounted on a wall, not facing
into direct sunlight and protected from the weather elements as much as
possible.
The DPH-64 should be installed near the treatment plant. Maximum
length of the co-axial cable used should not exceed 10 metres because
of the very high input impedance characteristic of a pH electrode.
(See Signal input)
The metal electrodes used for redox measurements are of much lower
resistance and longer coaxial cables can be used without any special
precautions.
Insert a round headed screw into the panel where the instrument is to
be attached. This screw determines the centre of the instrument location.
(Fig.3) Slide the instrument over the slot opening at the back, check that
the unit hangs level and secure it with two screws inserted through the
slots at the two bottom corners.
.1/ !
Attaching the DPH-64 to a wall
PAGE 8 DPH-64 Instruction manual
Wiring of the DPH-64
S1 and S2 have 240VAC active neutral and earth terminals, S3 and S4
are potential free with NO, C and NC contacts. A three way terminal
supplies 240VAC next to S3 and S4, thus simplifying wiring if a 240VAC
output is required for S3 and S4. Look up page 23 for wiring options.
It is imperative that all connections are wired through the cable gland
and the transparent lid is always tight to ensure that no corrosive liquids
inadvertently splash into the instrument.
Electrodes
The co-axial cable used to connect the electrode to the DPH-64 must
be of the type supplied with a carbon sleeve between the center core and
shield as any standard co-axial cable will cause a very erratic digital
display. An impedance converter must be used if the location between
electrode and controller exceeds 10 meters. Special consideration also
must be given when placing an electrode in a treatment bath or pool. The
point of injection of neutralising agent and placement of the electrode
(distance between them) largely determines the dosing characteristics of
the DPH-64.
FOnly use special co-axial cable to connect a pH electrode to the DPH-64.
Starting up the Instrument.
After you have installed the instrument and checked all the wiring and
connections open the isolation valves to the sensor to allow water flow
across it. Plug the power cord into the supply and switch on the DPH-64.
The LCD display lights up and shows pH and Time. Some LED’s may light
up depending on the electrode or simulator input present.
FAlways exit by pressing MODE when looking at configurations in the
various setup menus to ensure no unwanted changes are saved.
DPH-64 Instruction manual PAGE 9
CONFIGURATION
Both knobs (encoders) can be rotated and pressed to perform various
functions.
Pressing ‘MODE’ moves through Manual Dosing, Calibration/Set
Clock Time returning to the main window.
Pressing ‘VALUE’ is the shortcut to quickly change setpoints for any of
the relays outputs. (See Fig.4)
Default values for the DPH-64 instrument
The DPH-64 is shipped with a standard default configuration pro-
grammed in non-volatile memory.
Of course all values can be customised through the configuration setup.
Entered values are stored in non-volatile memory and are not lost through
power failure. An internal battery runs the real time clock if power is not
present.
Relays S1 to S4 enabled
Dosing Mode = SETPOINT (normal dosing)
Dosing S1 and S3 = UP
Dosing S2 and S4 = DOWN
Setpoint S1 and S3 = 6.00pH
Setpoint S2 and S4 = 8.00pH
P1 and P2 pulse output is disabled.
Temperature Compensation Manual (+20.0oC)
Temperature hidden from display
4-20mA normal output
Range 4mA = 0.00pH 20mA = 14.00pH
The DPH-64 automatically returns to themainwindowafter2minutesif,
for some reason, left anywhere in the configuration or calibration menu.
FThe DPH-64 automatically returns to the main window after 2 minutes if
left anywhere in the configuration or calibration menu.
PAGE 10 DPH-64 Instruction manual
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