Controller Specification Sheet

Transcription

1 Controller Specification Sheet MC9320AXXXBX Proportional Inhibitor Dosing, Conductivity Bleed Control, Redox Control of Oxidising Biocide and Secondary Biocide Dosing PULSAtrol Controllers are microprocessor based units specifically designed for a wide range of water treatment control and monitoring options. PULSAtrol 9000 units offer ease of installation as the controller and standard flow assembly housing all the relevant sensors and flow switches is supplied pre-mounted on a polypropylene backboard. MC9320AXXXBX is designed to dose inhibitor, on a timed or proportional basis, control bleed via conductivity control and control the addition of an oxidising biocide via Redox control. The unit also has spare timers available to be utilised as required. For example, a secondary non-oxidising biocide can be dosed on a 28 day cycle with up to 24 hour bleed lockout and pre-bleed. The controller allows the optimum dosage regime to be maintained in a cooling tower. The standard unit has a number of upgrade options to enable it to perform additional functions. Key Features Microprocessor based for accurate and reliable control Modular flow assembly with flow switch, quick release sensors and sample port mounted on a polyethylene panel Convenient keypad menu access, display contrast adjustment and Hand/Off/Auto relay control Self charging capacitor to maintain time and history for up to two weeks in the event of power loss to the controller DIN connections for conductivity sensor Panel mounted assembly for ease of installation Modular hardware and software for easy access and servicing IP65 High Impact Resistant PVC enclosure for protection against harsh environments Publication WTP/Ptrol/MC9320/03/08

2 Operation The treated water conductivity and Redox is continuously monitored by the integral cells in the Controller flow assembly which also incorporates a flow switch. The flow switch ensures that all the following controls are only activated when there is flow through the assembly. The ranges of the controller are; 0 to 1000 mv Redox and a selectable range for conductivity between 0 to 500, 2000, 5000, 10,000 and 20,000 microsiemen/cm. Factory setting is 5000 µs/cm. The Set point will be either Rising or Falling. Rising or Falling relates to the natural tendency of the treated water. For the Redox level the Set Point (factory set at 400 mv) will be Falling and oxidising biocide will be dosed when the set point is reached. For conductivity the required Set Point (factory set at 1500 µs/cm) will be Rising. This is because in a cooling tower the concentration of the circulating water will tend to rise and without any blowdown will continue to rise. The Redox control has a limit timer assigned to it. Blowdown Control The correct level of cooling water concentration is maintained by conductivity control. When the set point is reached the solenoid blowdown valve is opened. The solenoid valve will continue to be activated until the level falls below the set point by the Differential (factory set at 100 µs/cm). Then the solenoid valve will close. This is to prevent chattering of the output relay about the set point. Redox Control Redox "Falling" Set Point Redox Control Time The correct level of oxidising biocide within the cooling water system is maintained by Redox control Conductivity Dosage De-activated Dosage Activated "Rising" Set Point Conductivity Control Blowdown Activated Blow dow n De-activated Time High Alarm Differential Set Point Low Alarm High Alarm Set Point Differential Low Alarm As the treated water loses oxidising biocide reserve the Redox level will fall and without any dosage of oxidising biocide the reserve will continue to fall. When the Redox set point is reached the Redox limit timer will either open a solenoid valve on the inlet to a bromine dispenser or start metering pump(s) to inject the oxidising biocide reactant(s) - dependant on method of chemical addition being employed. The solenoid valve or metering pump(s) will continue to be activated until the level rises above the set point by the Differential (adjustable, factory set at 50 mv) then the control device(s) will be switched off. This is to prevent chattering of the output relay about the set point. However, if the Redox output is activated for the period set in the Redox limit timer (adjustable in 1 minute increments up to 23 hours 59 minutes, factory set at 1 hour 30 minutes) but the set point has not been satisfied then activation will be cut off and unit will go into alarm until it is re-set The system will also re-start if treated water condition is satisfied - e.g. if the water is manually dosed to adjust Redox level and satisfy the set point.

3 Inhibitor and Non Oxidising Biocide Control PULSAtrol MC9300 Controllers utilise the concept of tagable timers. Tagable timers offer much greater flexibility as they can be used to control any output device such as a metering pump or a solenoid valve in a wide number of alternative methods. In the MC9320AXXXBX Controller four tagable timers are available to operate the required output devices. Actuation can be by any one of the following modes; Limit; or lockout timer. If this timer is utilised, typically the inhibitor pump is actuated simultaneously with blowdown as controlled by the conductivity reading. In this mode the timer limits the length of time the metering pump can run during any single blowdown cycle. This safeguards against overdosing should blockage occur in the blowdown line for example. The timer is adjustable in one minute increments up to 23 hours and 59 minutes with an elapsed time display. Percent; also referred to as a cycle timer. The timer runs continuously on an adjustable time cycle, such as ten minutes, with the output being activated for an adjustable percentage of the time cycle. The timer is adjustable in increments up to 100% and the cycle time is adjustable from one to 120 minutes. Pulse with accumulator; also referred to as water meter or reset timer. This timer is the one normally used to control inhibitor dosing and accepts pulses from a water meter to actuate the inhibitor metering pump. The timer has an adjustable feed time (Run Time) in one second increments up to 59 minutes and 59 seconds with an elapsed time display. It has a built in accumulator that can count pulses up to 255 before activating the out put with an elapsed pulse counter. Also incorporated into the timer is a pulse totaliser that keeps an on-going count of the number of pulses received by the timer. Percent post blowdown; this timer is adjustable in one percent increments up to 100% of the blowdown time. The timer keeps track of the total blowdown time and activates the inhibitor metering pump when the blowdown deactivates for the percent of the total blowdown time set. The minimum feed time will be one minute.

4 28 day biocide timer with blowdown lockout and pre-blowdown is incorporated in the controller. This provides the ability to dose a biocide on a 28 day programme cycle via four individual programs with a wide range of day and week setting combinations. The dosage duration for the biocide metering pumps is adjustable in one minute increments up to 23 hours 59 minutes. (factory set at 1 hour 30 minutes). The time when actuation occurs can be varied as follows; Biocide Settings Month Week Day * No Month * No Week 4 th Week Sunday Thursday Odd Month 1 st Week Even Week Monday Friday Even Month 2 nd Week Odd Week Tuesday Saturday Every Month 3 rd Week Every Week Wednesday Every Day * If these options are selected, no biocide addition will occur. Blowdown Lock-Out; to ensure biocides are allowed their optimum contact time, blowdown can be prevented from occurring for an adjustable period after biocide dosage has ceased. The lockout time starts when biocide dosage is activated and is adjustable in one minute increments up to 23 hours 59 minutes (factory set at zero). Lock-out is common to all four biocide programs. Pre-Blowdown; the pre-blowdown function of this controller allows for the user to pre-blowdown in advance of the blowdown lock-out. This is to reduce the possibility of scaling due to increased levels of conductivity occurring during the blowdown lock-out period. Pre-blowdown is programmed to occur for a programmed length of time or until a pre-set conductivity limit is reached. The duration time is adjustable in one minute increments and is common to all four biocide programmes. Slaving Relays In addition to the above control options, each relay can be slaved to any other relay or combination of relays such that the slave relay actuation will follow exactly the actuation of the relay or relays it is slaved to. This enables more than one output device to be controlled in response to each input signal. Cables Certain cables are supplied with the controller and flow assembly mounted on the backboard. Sensor cables. All sensor cables are cut to the length required for installation into the provided flow assembly. Flow Switch cables. All flow switch cables are cut to length required for installation into the provided flow assembly. Communications cables. If the communications option is included, a 3 metre cable with a DIN connection on one end for plugging into the controller and a standard RJ-45 connection on the other end is supplied. If the communications option includes the modem, an RJ-45 to RJ-11 adaptor is supplied for connecting into a standard telephone jack.

5 Additional Equipment Requirements The MC9320AXXXBX Controller is a stand alone unit. To operate as a complete system the following equipment must be in place either existing or supplied in addition to the controller. Dosage Pumps The number of dosage pumps required will be dependant on the exact water treatment programme being employed. One pump will be required for the inhibitor. If liquid oxidising biocide is being employed, one or two pumps will be required dependant on then type of oxidising biocide. If nonoxidising biocides are being utilised, one pump for each chemical will be required. Care must be taken to ensure that the pumps are capable of delivering the chemical requirements specified by the controller. Chemical Storage Treatment chemicals will normally be stored in a chemical storage tank. Dosage can be from the container that the chemical is supplied in, but it should be ensured that a means of monitoring usage is available. Solenoid Valve A normally closed solenoid valve will be required for bleed control. If a solid oxidising biocide is being employed, a solenoid valve on the inlet to the dispenser will be required. Impulse Water Meter An impulse water meter will be required, for the cooling tower make up line, to monitor the rate of make up flow into the cooling tower. The K factor, i.e. the volume of water passing through the water meter between impulses generated, will depend on the individual operating parameters. Cables Depending on the options included in the relevant controller, certain cables are supplied separately to order. Water Meters All water meters inputs are available from a single DIN on the controller. When you order a cable for water meters, one end is terminated with the mating DIN for connecting to the controller. The cable is 8-conductor twisted pair. The other end of the cable has no terminals. Colourcoded stripped leads are available for wiring to your specific water meter. Analogue (4-20mA) Outputs All 4-20 ma outputs are available from a single DIN on the controller. When you order a cable for 4-20mA outputs, one end is terminated with the mating DIN for connecting to the controller. The cable is 8-conductor twisted pair. The other end of the cable has no terminals. Colour-coded stripped leads are available for wiring to your analogue output device. Volt-free contact Alarm All volt-free contact alarm outputs are available from a single DIN on the controller. When you order cable for volt-free contact alarms, one end is terminated with the mating DIN for connecting to the controller. The cable is 8-conductor twisted pair. The other end of the cable has no terminals. Colour-coded stripped leads are available for wiring to your alarm input. Options The MC9320AXXXBX is the standard control unit to perform the tasks defined above. If additional features are required, the following options are available at additional cost. Two 4-20 ma recorder outputs are available to drive chart recorders to provide hard copy of the measured Conductivity and Redox readings. Spanish, German or French language displays The PULSAworks communications package can be employed to provide remote or local accountability.

6 Specification Feature MC9320AXXXBX MC9320 Four tagable timers, two water meter totalisers user configured as either a volt-free contact or hall effect, alarm output relay, volt free contact alarm output, conductivity and Redox control with sensors and flow switch mounted in a flow assembly. Controller and flow assembly mounted on a polythene backboard. A Conduit which signifies cable gland connections on base of controller. X No ph settings X English. Varying the 9 th Digit calls up Default language options. A = Spanish, B = German, C = French No remote communications. Varying the 10 th Digit calls up additional cost Communications options. X A = Serial line communications including software. B = Internal modem communications including software. B CE approval X Standard panel with flow assembly Power input 90 to /60 Hz 100 VA Control Output Line 600 VA Display 8 line,64 x 128 Pixels Dot Matrix, Back Lit Graphics Display Electronic Environment to + 52 o C, 100% Humidity Shipping Weight of Backboard, Controller and Flow Assembly (kg) 9.2 Maximum Backboard Width (mm) Maximum Backboard Height (mm) 330.2

7 Cooling Tower Alarm Controller Heat Exchanger Circulating Pump Drain Chemical 1 Inhibitor *Chemical 2 Bromine Reactant A *Chemical 3 Bromine Reactant B Chemical 4 Alternative Biocide Make Up Water Schematic Illustrating Typical Installation Arrangement for PULSAtrol MC9320AXXXBX Inhibitor, Conductivity Bleed and Dual Biocide Dosage Controller - Cooling Tower Application Water Meter Dosage Pumps Union Flow Switch Y Strainer Redox Probe Conductivity Probe Input Power Not all items shown will be present in every application *Note; Method of bromination may be via a solid dispenser, in which case the two dosing pumps are replaced by a solenoid valve on the inlet to a bromine dispenser. Alternatively, the liquid oxidising biocide may be a single chemical, in which case only one pump would be employed. Solenoid Valve Y Strainer

8