1. What happens if the controller or the critical point sensor (P3 sensor) temporarily lose their GSM signal, e.g. because a truck has parked in the way?
The controller will continue to use the existing control algorithm to set P2 without any problem. This can continue as long as there are no major changes in the DMA. However there will be no continuous improvement of the algorithm. In the meantime, the P3 sensor or controller will keep trying to make contact at regular intervals. If after a few days, contact has not been re-established, an i2O service engineer will be alerted and will carry out a local inspection.
2. What happens if there is no GSM signal at all in the vicinity of the controller or the critical point sensor (P3 sensor)?
Data will be collected manually from both the controller and P3 sensors. The data will be used to generate the control algorithms using a portable version of the i2O server software installed on a local PC. Once the algorithm has been created, it can be uploaded manually to the controller. This process will need to be repeated at fixed regular intervals to take account of any changes in the DMA.
3. What happens if the controller or Advanced Pilot Valve (APV) malfunctions? Could the pressure go dangerously high or could the flow into the DMA be cut off?
A watchdog continuously monitors the health of the controller and the correct operation of the APV. If it detects a malfunction in either the controller or APV, it puts the whole system into safe mode. In safe mode, P2 is either maintained at a safe predetermined pressure or is varied according to a safe pre-determined pressure profile. The controller also sends out an alarm so that the fault can be investigated.
4. What happens if the DMA flow meter malfunctions? Could the pressure go dangerously high or could the flow into the DMA be cut off?
As soon as the flow meter begins to malfunction, the watchdog puts the system into safe mode i.e. P2 is set to a fixed, safe pressure and an alarm is sent out.
5. What happens if the PRV malfunctions? Could the pressure go dangerously high or could the flow into the DMA be cut off?
Unfortunately, this could still happen if the PRV failed. However, if this occurred, the controller would send out an immediate real time alarm. This would prompt emergency action to deal with the problem. A quick response prompted by a real time alarm would minimise the damage to the mains in the DMA or disruption to customers.
6. What happens if there is a fire at night when the PRV output pressure (P2) is low?
The controller would immediately sense the increasing flow rate into the DMA and would start increasing P2. If necessary, it would open up the PRV to give maximum P2. Once the fire had been put out, the controller would start to close the PRV to bring P2 back down again to its normal level.
7. Can the i2O system interface with existing data loggers that have already been installed on the network?
The i2O P3 sensor is an integrated component in the i2O system. The server interacts with the P3 device adjusting logging frequency, upload schedules and alarm thresholds. High accuracy and resolution are also essential to the system performance. Existing loggers will not provide the control capacity and accuracy.
8. Will the i2O system continue to operate if the valve chamber floods?
Yes. The controller and APV are IP68 and have been tested down to a depth of 4m.
9. What is the typical controller battery life?
This depends on the number of GPRS transmissions and pressure adjustments per day. The more often the pressure is adjusted, the more water is saved but the faster the battery is depleted. The controller settings are varied to give the optimum number of pressure adjustments depending on the conditions. A typical installation with 100 adjustments per day would have a battery life of five years with a single primary cell. However, i2O would normally be responsible for supplying and replacing batteries as part of its managed service.
10. What happens if the controller main batteries fail?
This shouldn't happen as the battery state is reported on regularly to give ample time to change them. However, if the main batteries do approach the end of their life, the controller goes into back-up power mode before the main batteries actually fail. In back-up power mode, the controller is powered by its internal back-up battery. P2 remains fixed at a safe, pre-determined level and no further adjustments are made. The controller continues to record new data and retains all existing data and settings in its large 2Mb memory. However, it stops communicating with the i2O server.
11. What happens if the P4 or P3 sensor main batteries fail?
This shouldn't happen as the battery state is reported on regularly to give ample time to change them. However, if the main batteries do approach the end of their life, the sensor goes into back-up power mode before the main batteries actually fail. In back-up power mode, the sensor is powered by its internal back-up battery. The sensor continues to record new data and retains all existing data and settings in its large 2Mb memory. However, it stops communicating with the i2O server.
If the P4 sensor main battery fails, this has no effect on the performance of the controller. However, if the P3 sensor main battery fails, the server will be unable to update the control algorithm. This will have a minimal effect as long as the P3 sensor battery is replaced within a reasonable time.
12. What happens if both the controller main battery and back-up battery fail?
This is very unlikely but if it did occur, the watchdog circuit would put the system into safe mode immediately. Data and parameters recorded in the controller would be lost.
13. Can batteries be changed in the field?
Batteries may easily be replaced in situ. Back-up batteries mean that no data or settings are lost.