User manual HANNA INSTRUMENTS BL 7916

[. . . ] Instruction Manual BL 7916 · BL 7917 pH and ORP Measuring & Dosing System www. hannainst. com Dear Customer, Thank you for choosing a Hanna product. Please read this instruction manual carefully before using the pump. If you need additional technical information, do not hesitate to e-mail us at tech@hannainst. com. These instruments are in compliance with the directives. PRELIMINARY EXAMINATION Remove the pump from the packing material and examine it carefully to make sure that no damage has occurred during shipping. [. . . ] The contact available on the terminals can be normally open or closed. It can be used as a switch to drive an external mixer when the pump is dosing, or can activate an auxiliary pump or any other device. With BL 7916, the contact can be selected to remain open when the pH value is within the set limits (the pump is not dosing) and closed when the pump is dosing or viceversa. By shorting the Common (middle) terminal with the NO or NC terminal on the driving circuit inside the controller section, a normally open or a normally closed state can be achieved, as shown below: · Adjust the SET FINE trimmer to display the exact setpoint value. · Once the desired setpoint is achieved, move the display selector switch back to MEASURE. ACID OR BASE SELECTION (BL 7916 only) If an acid chemical is to be dosed, move the ACID/BASE switch to ACID. This means that the pump will dose when pH measurements are higher than the setpoint. If an alkaline chemical is to be dosed, move the ACID/BASE switch to BASE. This means that the pump will dose when pH measurements are lower than the setpoint. ALARM CONTACT If the reading drifts from the setpoint by more than ±2. 00 pH in BL 7916 and ±200 mV in BL 7917, an external alarm can be activated. The contact is rated at 2 amps at 220VAC. No power is supplied through the system and it is an open/closed contact only. With BL 7916, the contact can be selected to be closed when the alarm is activated and open when the alarm is off or viceversa. Short the middle terminal located on the driving circuit inside the controller section with the NO or NC terminal (see above). REDUCING OR OXIDIZING SELECTION (BL 7917 only) If a reducing chemical is to be dosed, move the RED/OXID switch to RED. This means that the pump will dose when redox measurements are higher than the setpoint. If an oxidizing chemical is to be dosed, move the RED/OXID switch to OXID. This means that the pump will dose when the redox measurements are lower than the setpoint. The wires and cables needed for all connections can be fed through the two cable fittings located below the terminals. It is important to attach these cables properly because pump vibrations could loosen them. Replace the transparent cover and fasten the screws. 21 4-20 mA ISOLATED OUTPUT A 4-20 mA proportional output is available in these connections: 4 mA=0 pH; 20 mA=14 pH (BL 7916) and 4 mA=-999 mV; 20 mA=+999 mV (BL 7917). The output is optically isolated. 20 pH CALIBRATION BL 7916 only: · Ensure that the display selector switch is set to MEASURE and dip the electrode tip in a neutral buffer solution (pH 7. 01). TROUBLESHOOTING GUIDE ELECTRICAL The pump does not operate when turned ON: · Check the power supply and connections. Voltage should be between 100 - 130 VAC for 115 V models and between 200 - 250VAC for 230 V models. · See Installation section on page 11 or call your dealer or the nearest Hanna Customer Service Center for technical assistance. · Adjust the OFFSET trimmer to display 7. 01 on the LCD. OPERATING Display does not indicate: · Check that the pump is properly plugged in · Check the fuse. Display shows 1 on the far left hand side: · Check electrode and/or electrode cable. "No Dosage" LED is lit: · Check the tank where the level controller is working or verify the connection on the terminals (they must be short for the pump to dose). · Rinse the electrode with clean water and dip the electrode tip in pH 4. 01 (acidic) or pH 10. 01 (alkaline) buffer solution. [. . . ] This can be achieved by installing the electrode in such a way that it is constantly in a well filled with the sample (stream or tank). The protective cap can also be filled with HI 70300 storage solution if the electrode is not being used at all. Note: With industrial applications, it is always recommended to keep at least one spare electrode handy. When anomalies are not resolved with a simple maintenance, change the electrode to see if the problem is alleviated. 31 CHEMICAL COMPATIBILITY GUIDE PARTIAL LISTING OF CHEMICALS THAT CAN BE USED WITH BLACKSTONE PUMPS (Rated for 45°C. [. . . ]