FAQ

Frequently Asked Questions (FAQ) about Maidlabs’ products & services.

How can I use Mermaid to calculate my ROI on new pumps?

The default settings of Mermaid’s Evaluation Report shows the efficiency of the pumps of a lift station compared to the most efficient within this lift station. If you know that this new XYZ pump has an efficiency of x gallons per watt of electricity, then in the Cost area in the left pane of the Mermaid’s Evaluation Report analysis, set the “Compare with standard efficiency” to the efficiency of the new pumps. The Evaluation will update itself and show how many dollars per year could be saved using the new pumps.

How can I be sure that abnormal current phase balance is not caused by a faulty or inaccurate sensor?

Connect all 3 current sensors on the same wire. If you read the same value in Mermaid’s Real Time, then you know that the current sensors are accurate and if unbalanced displayed are really there.

Why ARE all LEDs off on the Mermaid every time I get back to the download its data?

The default setting of the Mermaid data logger is to have its LED’s operating when in communication with a computer, then up to half an hour after the end of the communication. It was set this way to maximize the battery operation. If the Mermaid is connected to AC, this setting can be set to Always ON.

What is the difference between a SCADA software and Mermaid or MaidMaps?

SCADA means Supervisory Control And Data Acquisition, therefore it is made to remotely control equipment and record data. There is nothing in this word related to processing the recorded data and the quantity of data required to do this processing.

A SCADA software is a generic software, like Excel customized specifically for the need of its user. If its basic programming isn’t done, you’ll get a blank sheet like in Excel. The quality of the SCADA software is directly related to the capacity of the engineers who specified its functions and the integrators who programmed them. Most
engineering firms use specifications prepared by suppliers or integrators.

Maid Labs has invested 20 years in the development of volumetric algorithms, which is why softwares like Mermaid and Maid Maps exist. Maid Labs’ software go further and show where money can be saved, what might break next, and where the infiltration is, etc.

Can I use a cellular modem to download my data?

Yes, through the Ethernet port.

What is the difference between your Volucalc and the one I bought 15 years ago, the one that I still use today?

Technology, accuracy, information on display, quality of the reports, Internet connection, USB download, etc.

What is the difference between Volucalc and Volucalc RT.

Volucalc is able to calculate flow in and out of a pump station, at the end of a pump cycle, but it could also takes a few cycles, depending of the conditions. So Volucalc’s flow isn’t in real time, which is not the case for Volucalc RT. The flow algorithm within Volucalc RT is more sophisticated. Also, its algorithm can be used to calculate the volumetric capacity of the pipes feeding the lift station, which is something Volucalc cannot do. If the goal is to have the lift station flow calculated by Mermaid at a later time, then both products can do the job.

Why are you the only manufacturer of new models of volumetric flow meters?

We are not the only one, but we are the only manufacturer that is selling a model created by our staff back in 1992! Another major flow meter manufacturer had one on the market, but removed it after only 2 years. Why? Calculating a volumetric flow under perfect conditions is very easy, but 99% of the lift stations do not operate under these conditions all the time. Maid Labs’ staff invested over 20 years on improving their “what if” functions, in order to compensate for possible abnormal behaviors. It simply takes too much time and investment to create an accurate volumetric flow meter.

How do I select the right current sensor model for the type of equipment monitored?

Ultimately, the goal is to maximize the resolution of the current reading without missing any valuable data. With motors, the problem is that the starting current peak is 5 to 6 times higher than the normal current draw. This means that if you want to record the current peak, the normal operation current readings will be 5 times less accurate then they could have been if the current sensor selected would have been targeted at maximizing the accuracy of the normal operation current. Suppose that you have a 10 HP pump using about 10 Amps when operating normally.

If the goal is to maximize the accuracy under normal operation, then a current sensor 50% higher than the capacity of the pump would be ideal. If the goal is to record the peak, then a current sensor slightly higher than the maximum peak will do the job. MAID Labs current sensors have the following capacities: 5A, 15A, 75A, 150A, 300A and 1500A. Custom orders can be placed.

Do I need the voltage transformer unit to calculate the pump efficiency?

Using the voltage transformer increases the accuracy of the power consumption calculated. However, because the voltage is usually very stable, it is possible to manually enter the voltage in Mermaid, Volucalc and in Volucalc RT. This slightly reduces the accuracy of the power consumption used by the pumps, and therefore the accuracy of the pump efficiency. Still, this power consumption is better than not having this valuable information.

What is the difference between the Overflowmeter and an open channel flowmeter?

Open channel flow meters usually have all the formulas preprogrammed in their software, while Overflowmeter only has those required by their specific application.

What is the short version of how volumetric flow is calculated?

The patent describing the flow algorithm developed by Maid Labs has 30 pages and does not include the other formulas used when abnormal pump, level or electrical behaviors occur. There is no short way to explain how Maid Labs calculates flow in every possible situation.

What is pump efficiency and how can I use this?

The pump efficiency is the volume pumped per unit of energy used. For pumps, it’s the number of liters or gallons per watt of electricity. 90% of the cost of a pump over its life time is electricity. If a pump costs twice as much to operate as before, even if it pumps the same flow as before it would be important to know this. Other than increased electric bill, a major variation of the pumps’ efficiency indicates that something other than flow is highly abnormal.

I only get 3 days of data in the Mermaid but I was expecting 3 weeks. What is going on?

Mermaid records about 500,000 triphase and analog readings before the memory rolls over. For most lift stations, this represents 3 to 6 weeks of data. If a highly variable sensor is connected to the analog input and the percentage of variation required to trigger a record is set to maximum precision, then it is possible to generate over 500,000 records in as little as 3 days. The solution is simply to reduce the accuracy of the analog input.

How can I erase all THE data in the Mermaid instrument?

In the Tool menu of the Mermaid software, under Device Setup, two of the functions are to set the time to the user’s computer time (Update Time), but one of them also indicates it will erase the instrument memory.

How is the data recorded in the Mermaid?

Every tenth of a second, Mermaid reads all of its inputs, compares the readings to the values in memory, and then records those that have changed by more than 0.2%. The 4-20mA/0-5V analog input of the Mermaid is the only input that the user can specify and the percentage of variation required in order to generate a record.

I want to record the quantity of water lost during a sewage overflow event. Which product do you suggest?

The Overflowmeter records level from 4-20 mA analog level sensors. The Manning formula or any other formula can be programmed in the instrument. With this algorithm it is possible to evaluate the quantity of liquid lost during a sewage overflow event.

I simply want to record when an event occurs. HOW do I do this and how difficult is it to retrieve my data?

The EE-400 is a battery or AC operated data logger which records when events occur. The watertight EE-400 will operate for more than one year on batteries under normal conditions. It has one digital input display to show each event and a cumulative per day and month display. Also, it generates detailed and summary reports in Excel format.Data is simply copied to a USB drive.

Can I use MAID Labs’ algorithm within my own telemetry software.

There are so many telemetry softwares available and making our algorithm compatible to every one of them is simply impossible. But if it was possible, the quantity of data required to be transferred from the RTUs would be so great that the communication channels would not leave any space to report emergencies. We do not know of any RTUs with the memory or processing capacity doing what the Volucalc RT does.

We already have a state of the art telemetry system with brand new RTUs. Why would I need your product?

SCADA software is the base of the telemetry system. This software is usually programmed by an integrator to reflect the requirements of the engineers who have specified the features. 99% will specify that the pump status shall be remotely visible and a remote control possible. The staff at Maid Labs have invested near 20 years in the development of their accurate flow algorithms. We have intergrated hundreds of potential scenarios into the algorithm so it can perform properly. Lift stations change daily and for a telemetry system to be constantly correct we assume nothing changes at the lift stations, this is impossible. Maid Labs Volucalc RT is a state of the art volumetric flowmeter and has the entire flow algorithm within the instrument. Accessing the instrument’s processed data can be done using the same Ethernet access that is used to communicate to the RTU.

Volucalc RT has an analog output proportional to flow, which can be connected to the RTU. It is important to remember that an RTU is not a flowmeter. It does not have the processing capacity or the memory required to do the type of flow calculation performed by Volucalc RT. The next question explains why it should not be done in the telemetry software.

I’ve been using the hour meter for decades to figure out the flow. How is your system different?

Like any electrical component hour meters can become defective but not broken, and record an abnormal number of hours. When was the last time you verified the precision of your hour meters? if they are not reliable the flow or cumulative volumes are based on defective equipment. If the hour meters are operating properly how exact are the pump capacities used in the derived flow formula? A difference on 10% of capacity between 2 pumps, could cause one of them to run 50% longer than the other and it could be normal. How do you know that the difference in run times of the pumps is normal or abnormal without knowing its present flow rate? In today’s technological world, using hour meters is like using horses vs. cars.

Can you calculate flow with current?

Yes and no. In theory, current is proportional to the effort made by the pump, therefore its flow. In reality, the height of the level in the well, the pressure on the other side of the pump, and the liquid viscosity, also the deterioration of the pumps and even the voltage influence the current being used by a pump. So in a highly controlled lab, it could be possible to use current to calculate flow, but in a lift station it is not reliable.

When should I not use a volumetric flow meter?

Volumetric flow is related to the use of a mathematical formula requiring a constant volume between two levels in the wet well. Most of the time it is not possible to get this constant volume when the influent pipe is between the operating levels of the pumps. This situation requires the derived flow algorithm. The Mermaid software uses both the volumetric and derived flow algorithms to generate all of its analysis and reports. Mermaid can also use the volumetric formula for part of the pump cycle and the derived flow formula for other parts of the cycle.

How accurate is volumetric flow?

Volumetric flow meters use a constant volume within know levels in the wet well to calculate a 100% accurate average flow, this is done during the filling portion of the lift station pump cycle. Assuming that the entered dimensions or volume is accurate, volumetric flow meters are the only flow meter able to claim 100% accuracy. When the pumps run interpolations, averages, quadratic equations and other mathematical algorithms are used to estimate the most probable flow in the station. Selecting the algorithm that reflects the most accurate real flow for this portion of the pump cycle is a trade secret, and it is the key to the accuracy of a volumetric flow meter. Over the last 20 years, Maid Labs’ staff have written multiple patents related exclusively to this technology.

Why is MaidLabs power meter different?

Like multimeters, there are many power meters, MaidLabs’ is the only battery operated (or AC) unit recording current and voltage for weeks, on multiple triphase equipment.

Is it intrinsically safe?

An “intrinsically safe” classification and design means that an electronic circuit and it’s wiring will not cause any sparking or arcing and cannot store sufficient energy to ignite a flammable gas or vapor, and cannot produce a surface temperature high enough to cause ignition. Such a design is not explosion proof, nor does it need to be. High-power circuits such as for electric motors cannot use intrinsic safety methods for protection. When our instruments are installed in the same location as motor controls, “intrinsically safe” is not required. If our instruments is located in a hazardous area having explosive gas or vapor, most of the time, a cellular modem or external battery will be part of the installation and those are not “intrinsically safe”. The sensors supplied with the instruments are sealed, therefore no gas or vapor could get to any area of the sensor that could generate ignition conditions.

Is it CSA or UL approved?

Most electronic product manufacturers (Acer, Epson, etc) do not have the CSA or UL approvals directly on their main equipment because they operate on low voltage … like the MerMaid, Volucalc, etc. It is on the power supply of their products, which are connected to higher voltage, that you can see the CSA/UL sign. To have a CSA or UL approved panel, everything that should be approved must be approved, but it is not everything. Most low voltage/low current equipment are not required to have it, but many do not know this.

How can I setup my COM port to communicate with MerMaid?

It is possible to find and to change the COM port number used by the computer to communicate with MerMaid … or any serial devices.

Simply download the following instruction:

 Mermaid_USB-to-serial.pdf

What are the steps to set up a new station file in MerMaid Software?

      • Click on the icon “New Station File”
      • You first need to name the pump station (General Information window).
      • For a fast set up, click on “Create a general station”.
      • In the Datalogger Device window, click on the text in blue “Select connected datalogger” or “Connection”. You then must select the port to connect your datalogger.
      • In the “Simplified sensors setup” window, select the options that you used on the installation at the pump station. But in any case, you can still change it later. For example: 2 motors count, 3 phases, voltage input on motor 3, system WYE, standard sensors MLCT5-15-75 (choose between 5A, 15A and 75A).
      • In the next window, select the appropriate power source.
      • In the “Time” window, make sure to update the time and erase events of the recorder, especially if you intend to monitor different pump stations with the same datalogger.
      • You can add the missing information afterwards, like the dimensions of the wells or the start and stop levels of the pumps.

Here are the steps to see if everything is working correctly:

              • Click on the icon “Real Time” (you need to be connected to a datalogger to see real time values).
              • If the Motor 3 is connect on Voltage sensors, it should always show something at M3 or on the Motor 3 dial.
              • Check if each pump is detected by the Software. When a motor starts, you should see the needle of this motor moving. For example, if you choose to connect the MLCT5-15-75 (set to 75A) to the datalogger and the values showed in the dial are too small, it means that you should probably set the sensor to 15A.
              • In the same window, check if the date and time are correct.
              • In the same window, check also if the batteries are good. If there is no power supply connected to the data logger, be sure to have batteries over 2.6 volts for a few weeks of data logging.
              • In the same window, when the rain gauge is connected, check if there is a pulse count recorded. You can simulate one by rocking.

To produce the reports, you need to download the events (click on the icon) while connected to the datalogger.