Georg Fischer 5700 Operating Manual

Signet 5700 pH/ORP Monitor - ORP Instructions

d

English

*3-5700.090-1*

3-5700.090-1 Rev. K 3/06 English/ORP

Contents

1. Power Connections

2. Compatible Electrode/Preamp Wiring

3. 4 - 20 mA Current Output Connections

4. Relay Connections

5. Relay Operation

Remove terminal blocks for easy wiring

1.

Freq. IN

Sen. Pwr.

Open Collector
Sensor

12-24 V

10 W

+

+

Iso. Gnd

output

1 2 3 4

2

1

Gnd

+

Gnd

Total

AUX

PLS

reset

output

-

1 2 3 4 5 6

Std. Sensor

LISTED

U

L

77CJ

1 2

Freq. IN

Flow

Patent No. D376,328

2.

CAUTION!

• Refer to instruction manual for more details.

• Remove power to unit before wiring input and output
connections.

• Follow instructions carefully to avoid personal injury.

6. Menu Functions

7. Parts and Accessories

8. Specifi cations

9. Quick Reference Menu Parameters

10. Troubleshooting

11. Maintenance

3.

1 2

Std. Sensor

U

L

1 2

1 2 3 4 5 6

Freq. IN

LISTED
77CJ

Freq. IN

Sen. Pwr.

Open Collector
Sensor

12-24 V

10 W

+

+

Iso. Gnd

output

1 2 3 4

1

Gnd

+

Gnd

Total

AUX

PLS

reset

output

-

2

Flow

Patent No. D376,328

1. Power Connections 2. Compatible Electrode/Preamp Wiring

CAUTION!
Never connect 110 VAC or 220 VAC to

rear power terminals. High voltage AC
will damage instrument and void warranty.

5700

12-24 V

10 W

Terminals

External power

+

-

= Double Insulate

= DC or AC power

supply

-

+

12 - 24 VDC

OR

12 - 24 VAC

Technical Notes:

• To reduce the possibility of noise interference, isolate AC power lines from signal lines.

• Maximum 4-20 mA loop impedance (sec. 3) is affected by the supply voltage.

• Use six conductor shielded cable for cable extensions up to 120 m (400 ft) max. (#5523-0064)

• Cable shield must be maintained through cable splice.

Silver (earth ground)

Brown

Blue

Green

White

Red

Black

T -

T +

Green wire

V +

White wire

Red Wire

Blue wire

Brown wire

Iso. Gnd

mV Input

V -

Black wire

+

4-20

mA

Preamp:
Signet 2720

Twist-Lock

-

Electrodes

pH/ORP

5700
Terminals

Preamp:
Signet 2760-1
Signet 2760-2

DryLoc
Electrodes

3. 4 - 20 mA Current Output Connections

Technical Notes:

**1/8A fuse recommended (customer supplied)
* 4-20 mA output is internally powered (non-isolated), maximum

loop impedance 350 Ω with a 12 V instrument supply voltage,
950 Ω with a 24 V instrument supply voltage.

To isolate output and prevent ground loop problems:

1. Use monitor device with isolated inputs, or

2. Use separate DC supply for 5700 and monitor device, or

3. Power 5700 with12 - 24 VAC step down transformer

Fuse**

1/8A

+

4-20

mA

4 - 20 mA

+

*

-

-

pH/ORP

5700
Terminals

4. Relay Connections

Two internal relay contact sets (COM, NO, and NC) may be used
for external device control. Front panel LED annunciators indicate
the activation status of each relay. Each relay can control up to
two devices simultaneously, as shown. Relay operation modes
include Low alarm, High alarm, and Proportional Pulse (sec. 5).

Common device connections include:

• Pulse mode - metering pump control

• Pulse mode - solenoid valve control

• Low or High mode - warning lamps

• Low or High mode - bells or sirens

• Low or High mode - external heavy-duty relay

Wiring Example Right

Device A IS powered when relay 2 is de-energized (front panel
LED “off”). Power is discontinued when the relay 2 setpoint is
reached (front panel LED “on”). Device B IS NOT powered when
the relay 2 is de-energized. Power is applied after the relay 2
setpoint is reached.

5. Relay Operation

A. LOW alarm mode

The relay is energized when the ORP drops
below the setpoint, and is de-energized when
the ORP rises above the setpoint plus
hysteresis (sec. 6.3D, 6.3E).

Low setpoint=

Adjustable hysteresis=

Relay energized=

Relay de-energized=

ORP

Relay

Energized

C

NO

NC

5700

Terminals

NO

C

NC

+

External AC/DC

Relay 1Relay 2

NO

power

Relay

De-energized

C

NO

NC

C

NC

Device

+

A

-

-

-

Device

B

+

Technical Notes:

• Maximum relay contact ratings: 5 A @ 30 VDC, 5 A @ 125
VAC, or 3 A @ 250 VAC

• An external heavy-duty relay must be used for devices with
surge currents or operating currents that exceed the above
specifi cations.

B. HIGH alarm mode

The relay is energized when the ORP rises
above the setpoint and is de-engergized
when the ORP falls below the setpoint plus
hysteresis (sec. 6.3D, 6.3E).

High setpoint=

Adjustable hysteresis=

Relay energized=

Relay de-energized=

ORP

C. Proportional PULSE mode
The proportional pulse relay configuration is primarily designed for metering pump control. The
operator is prompted to enter a minimum and maximum ORP setpoint and maximum pulse rate for
the assigned relay (sec. 6.3F, 6.3G). Relay pulse width is fixed at 130 ms. Refer to the operation
examples below.

• Metering pump chemical addition (dry contact activation type required)

Example 1 (right):
As the process ORP rises above the minimum pulse setpoint (-500 mV) the relay
begins pulsing; triggering the metering pump for chemical addition. As the ORP
continues to rise, pulsing accelerates proportionally until the maximum programmed
pulse rate of 300 pulses/minute and setpoint (+500 mV) are reached, forcing the
process ORP back down to intended levels (e.g. ≤ -500 mV).

ORP

-1000
mV

Example 2 (right):
As the process ORP falls below the minimum pulse setpoint (+500 mV) the relay
begins pulsing; triggering the metering pump for chemical addition. As the ORP
continues to decrease, pulsing accelerates proportionally until the maximum
programmed pulse rate of 300 pulses/minute and setpoint (-500 mV) are
reached, forcing the process ORP back up to intended levels (e.g. ≥ +500 mV).

-1000
mV

2

300 pulses

0 pulses

Relay 1 Rate:

300 Pulses/min >

Relay 1 or
Relay 2

-500 mV

3

300 pulses

Relay 1 or
Relay 2

-500 mV

Signet 5700 pH/ORP Monitor - ORP Instructions

+500 mV

0 pulses

+500 mV

+1000

ORP

+1000

mV

mV

6. Menu Functions

ENTER

To access either CALIBRATE or OPTIONS menus, press and hold
the ENTER key as illustrated below:

Menus:

• VIEW menu (sec. 6.1): The VIEW menu is displayed during

standard operation. The operator can navigate freely through
the menu by pressing either UP or DOWN arrow keys.

VIEW

(sec. 6.1)

CALIBRATE

(sec. 6.3)

OPTIONS

6.1 VIEW Menu

1

Choose:

↓G

A.

ORP mV/Raw mV

(sec. 6.4)

Press & hold ENTER key
for access:

ENTER

2

seconds

seconds

Change:

• CALIBRATE Menu (sec. 6.3): The CALIBRATE menu contains
all critical display setup and output parameters. A simple secu­rity code feature prevents unauthorized tampering. The operator
is required to enter a simple access code for menu access. The
same code also unlocks OPTIONS menus.

• OPTIONS Menu (sec. 6.4): The OPTIONS menu contains
setup and display features that are seldom accessed for minor

5

display or output adjust­ments.

• Reversible Dial

Your 5700 includes a

reversible dial face for
pH use. See enclosed
pH manual for opera-

BA

0 - 14 pH

ALARM 1

pH

ALARM 2

0

D

14

C

ALARM 1

ORP

ALARM 2

-

1000

+1000

tion details.

2

3

Save:

Menu Displays A - G:
(Factory default displays shown in
menu column 1)

A. Shows calibrated solution ORP

mV and Raw (uncalibrated) input
mV from ORP electrode/preampli­fi e r

B.

C.

D.

E.

F.

Last calibration

G.

Buffer calibration

Loop output

Range

Relay 1

Relay 2

Press and release to access
EASY CAL Procedure

↑A

See EASY CAL Procedure (Section 6.2)

B. Loop output display: shows the

loop current output level.

C. ORP range display: shows the

programmed min and max meter
range (sec. 6.3A)

D. Relay 1 display: this display

shows the programmed opera­tion mode and setpoint for relay 1
(sec.

6.3D-E)

E. Relay 2 display: this display

shows the programmed opera­tion mode and setpoint for relay 2
(sec.

6.3D-E)

F. Last calibration: this display

shows a user defi ned setup date
for

maintenance records. This

feature is not an internal timer or
calender.

G. EASY CAL: press the right arrow

key to access the EASY CAL
buffer calibration procedure (sec.

6.2).

Signet 5700 pH/ORP Monitor - ORP Instructions

3

6.2 EASY CAL Procedure

Requirements

• This procedure simplifi es system calibration using standard pH 4.0 and 7.0 buffers saturated with
Quinhydrone (customer supplied). If standard pH 4.0 and 7.0 buffers and Quinhydrone are not
available, the system can be calibrated using the CALIBRATE menu standard and slope settings

(sec. 6.3B, 6.3C).

• Quinhydrone (customer supplied) is the oxidizer measured by the ORP electrode and is essen­tial for EASY CAL calibration. To guarantee saturation with pH 4.0 and 7.0 buffers, mix 1/8 g (1/4
mL) of Quinhydrone powder for each 50 mL of pH buffer solution (sec. 7).

1

To Calibrate:

Place electrode tip in
first pH buffer saturated
with Quinhydrone;

pH 7.0 ≈ 87 mV
pH 4.0 ≈ 264 mV

Place electrode tip in
second (different) pH
buffer saturated with
Quinhydrone;

Press keys in sequence

will appear during code entry.

2

Response:

Allow for stabilization Press

1

30 seconds*

Allow for stabilization

to continue,

3

To Accept:

ENTER

to accept

first buffer calibration.

ENTER

Press

second buffer calibration.

to accept

Displayed Data

• ORP mV: Shows the calibrated
solution oxidation reduction
potentioal (ORP).

• Input mV: Shows the actual
Raw (uncalibrated) preamplifi er
ORP electrode input

For best results, gently stir the
submerged electrode for
approximately 5 seconds during
the stabilization period (step 2).

pH 4.0 ≈ 264 mV
pH 7.0 ≈ 87 mV

To exit EASY CAL at any time
without saving changes:

2

30 seconds*

quick

press

Display returns to VIEW
Menu in 3s

Technical Note:

The differences between input mV and ORP mV is a good indication of the electrode's condition.
Differences in excess of 50 mV may indicate a need to service the electrode. Refer to electrode
manual for maintenance recommendations.

Theoretical mV values
pH @ 25 °C mV
2 +296
3 +237
4 +177
5 +118
6 +59
7 0
8 - 59
9 - 118
10 - 177
11 - 237
12 - 296

4

Signet 5700 pH/ORP Monitor - ORP Instructions