FAQ
Yes. The cable is custom but it’s just shielded cable. It’s not like a pressure transducer where the cable cannot be cut because of a vent tube. You can cut the cable and wire into a junction box and then use the remaining cable to wire from the junction box to the control panel.
It’s often the first question asked by someone who works with lift stations. The FOGRod should be hung in the turbulent part of the well, near the inflow (but not directly under it). In this part of the well the grease is all broken up and causes a lot less problems than the grease in the quietest part of the well – where the floats are usually sitting.
The turbulence and agitation of the rod keeps it cleaner – but of course, grease still builds up on the rod. Because the grease is broken up, liquid still gets through to allow an electrical connection between the wastewater and the metal contacts on the FOGRod.
Here’s a bad well in Tennessee. The photos show just after installation and around two months after the last clean. The FOGRod is still working fine in the left hand photo!
Level sensor replacing floats, covered with grease, and working fine
Eventually the buildup does get so bad that the measurements are affected. The LIT detects these problems and provides a visual alarm as well as a relay contact closing (or opening) to give you a telemetry alarm (or an alarm on top of the panel). How long does it take before this happens? It depends on the well, the grease, the location of the FOGRod – but a typical guide is 3 months for a bad well, 12 months for an “average” well and never for some wells. And the key point is that the FOGRod can very easily be cleaned – using the cleaning pad or “squeegee” in the mounting bracket. It’s much easier to clean than floats.
We sell the FOGRod through a network of exclusive distributors in some regions and direct elsewhere. If you see a distributor for your state in this list, please contact them to purchase a FOGRod. If there is no distributor please contact us on 406 545 3023 or sales@wastewater-level.com.
And of course, we are always delighted to talk to customers and prospective customers – so you are welcome to contact us directly even if there is a FOGRod distributor in your state (but all purchase orders will need to go through the distributor).
Just email us at support@wastewater-level.com, or call us on 406 545 3023 and we’ll send you an electronic copy of the manual (pdf format).
Changing a bubbler system to the FOGRod is pretty simple. The important question – is the bubbler actually doing pump control as well as measuring level?
The LIT gives a level output (10 relays + analog output), but doesn’t do pump control.
If the bubbler is not doing pump control then it’s very easy – it is probably feeding an analog signal into something else (e.g. a pump controller, a PLC). Connect the analog of the LIT into the same place and you have replaced the bubbler.
One important point – if it’s an analog output, the range of the bubbler may be different from the range of the LIT. Our unit gives 1mA steps for each 6″ or 9″ (depending on the length of the FOGRod). Someone may have to change the setpoints in the PLC or pump controller. It’s the exact same issue when replacing a pressure transducer.
If the bubbler is doing pump control then you need to add something along with the LIT. Usually an alternating relay will be all you need – the additional cost is under $100 and there are lots to choose from. Anyone who has wired up or maintained lift station panels will be able to take care of this.
For completeness.. a note that the LIT can do basic pump control without alternation. You just use the auxiliary on the starter to hold in the run signal once the pump starts. For example, suppose contact 5 is your start point and contact 1 is your stop point. Relay 1 will break the circuit – i.e., stop the pumps. Relay 5 will start a pump – that is, be wired to one of the starters. The auxiliary from the starter will hold in the starter once the pump is running (and the level drops below contact 5).
The FOGRod hangs from its own cable – it is designed for this. It comes with a mounting bracket that you fix under the hatch so that the FOGRod can hang in the turbulent part of the well – near the inflow. The mounting bracket also comes with an S-hook and a zip tie – loop the cable so that the FOGRod will hang near the bottom of the well, use the zip tie and hang it from the S-hook:
You can see more installation photos here
The cable to FOGRod connection can support at least 180 lbs of weight so there’s no problem with the weight of the rod, even with huge buildup – or with pulling the FOGRod up through the squeegee that is part of the bracket.
You can see the cost on the pricing page. These prices include delivery within the continental US. The standard system of the FOGRod and LIT costs $1,080.
We are often asked – “we are replacing a float system, do we need anything else apart from the FOGRod and LIT?“. The answer – no, so long as you have 12v or 24v dc available in the panel to power the LIT. Otherwise you will also need a mains to 12v or 24v dc power supply. We supply one for $50 (slim, DIN-rail mounted) – or you can use any power supply so long as the output is at least 4W.
Yes, you can replace a Multitrode® “probe” with a FOGRod.
The FOGRod has 10 metal contacts like the “probe”, and 11 wires instead of 10 (so you don’t connect the 11th wire: FS).
Multitrode usually calls the top contact “1” and the bottom contact “10”, whereas we call the bottom contact “1” and the top contact “10”.
So when connecting up a FOGRod to a Multitrode unit, connect wire 1 (black) into their input 10, wire 2 (red) into their input 9 and so on. You can see the color code for the FOGRod in this question.
For reference, the 11th wire from the FOGRod allows the LIT (a Wastewater Level product) to carry out a loop-back test to check cable integrity – you don’t wire this 11th core into a Multitrode unit.
The FOGRod is a “simple apparatus” as described in NEC 504.4 and therefore does not need to be listed. It just needs to be installed in an intrinsically safe circuit. (See Division 1 Classification of the FOGRod). This is easily achieved with an appropriate off-the-shelf barrier.
Wastewater Level has tested two barriers and approved them:
– R Stahl: 9002/77-220-146-001
– Pepperl & Fuchs: Z967
Both of these are 2-channel barriers, so you need 6 in an installation (10-channels + 1 channel for the cable loopback test), however, their footprint is quite small, each barrier is about the size of a deck of playing cards. Each Stahl barrier is 0.5″ x 4.1″ x 2.8″ (WxHxD).
And we’ve negotiated some good pricing when these are purchased for a FOGRod system. Contact us for more information.
An installation in Illinois – the LIT and 24v power supply in the top right and the intrinsically safe barriers at the bottom:
Yes. The LIT works on the same principle as the Multitrode® controllers – it applies a low a.c. voltage to each of 10 contacts on the level device (FOGRod or “probe”) and looks for current flow to ground.
So if you have a Multitrode “probe” in a well in good condition and you need to replace a Multitrode controller the LIT can be installed. There are two important points to note:
a) the LIT is expecting to “see” a 60kOhm resistance between input 10 and FS (50kOhm to 70kOhm will be fine). You can buy a 60kOhm resistor from somewhere like Radio Shack for a few cents. Connect it between FOGRod input 10 and FS. (If you don’t, the LIT will measure level just fine, but you will have an alarm light on the LIT).
b) Multitrode controllers range from the simple MTR relay, the MTIC indicator controller, the MT2PC pump controller through to the MultiSmart pump controller. The LIT does not replace the control function, only the level measurement.
Contact us if you would like to find out how to replace your Multitrode controller with the LIT. As an example, the MT2PC has been replaced by the LIT and an alternating relay and in another case by the LIT and a Healy Ruff controller and in both cases the cost saving was considerable. The MT2PC typically costs around $2300, whereas the LIT costs $520.
That’s a good question and we say it’s definitely a good recommendation – even though the LIT & FOGRod have “internal backups”, where any problem with one (or even more) contacts will not stop the system working (read how we do it). So the high level float backup is only needed for complete failure of the LIT or of its power supply. The LIT is a very tough unit but everything electronic ultimately fails, even if it takes 30 years.
Here is our thinking on a redundant high level float..
Generally, adding redundancy isn’t trouble free, as many people who have spent time trying to design redundant systems will testify. It seems counter-intuitive, but often redundancy can add complexity and create more opportunities to fail.
However, the case of a high level float has two factors in its favor – first, it is low cost; and second, the “redundancy” is simple, because we have a very simple “switch” wired in parallel into an on/off circuit (e.g. red light on top of the panel).
Basically, floats are very reliable when they are not in wastewater, so as an occasional “once in a blue moon” alarm it can be expected to work. It is almost never in wastewater so you aren’t going to get a false “on” reading. It will just stay hanging there, in the “off” position.
Wiring it into the panel is also very simple. You don’t need a complex redundancy controller, or complex PLC software to determine which system has failed. You just wire the two cores from the one float into the red light circuit so when the float tips, the light comes on – easy to wire up, easy to understand and easy to test. Alternatively, you can wire it the same way into a telemetry system to call out an operator.
Using a high level float to start a pump (instead of generating an alarm) is a little more complex because now you want to turn the pump off at some point, otherwise you might run the pump dry and do some damage. Now you have two options, either run the pump for a fixed time or have an off float. In either case, you have a little more design work to do, but it’s still a pretty simple system. If you use two floats you definitely need to have the off float above the normal operation of the well, otherwise you will end up with the off float coated in grease and perhaps stuck in position when you needed it to take over.
In summary, if you can have a backup which is simple, easy to understand, easy to test periodically and won’t compromise normal operation then it’s a good choice. A high level alarm float definitely fits this category.
No, we think it’s a bad choice, here’s why..
Generally, adding redundancy isn’t trouble free, as many people who have spent time trying to design redundant systems will testify. Often, redundancy can add complexity and create more opportunities to fail.
The low level float is in wastewater the whole time and even though it is sitting below the worst of the grease, it still has plenty of opportunities to get grease buildup – and if not, plenty of opportunities for other debris in the wetwell to get tangled up around it.
If you use the low level float only as a telemetry alarm (or for the red light on top of the panel) then you aren’t compromising the reliability of starting and stopping the pumps – and it’s not a bad choice, the downside is it might create some false alarms. But you can judge that over time and remove it with little consequence later.
If you use the low level float to stop the pumps then you might be compromising the reliability of starting and stopping the pumps – and it will probably be a bad choice.
One of the great features of the FOGRod is the reliability of the OFF signal. Once the water drops off the bottom of the rod there is no way for current to flow through fresh air to ground. The low voltage applied to each contact on the FOGRod has to jump through fresh air to the receding water level below. This means you will always get an OFF signal and you can always rely on your pumps stopping.
Even if the LIT fails (or power fails to the LIT) you will get an OFF signal because the level relays will all spring open. That’s why a low level float is unnecessary.
Even though it seems on the surface like a good idea, we suggest not having a low level alarm, here’s why..
One of the great features of the FOGRod is the reliability of the OFF signal. Once the water drops off the bottom of the rod there is no way for current to flow through fresh air to ground. The low voltage applied to each contact on the FOGRod has to jump through fresh air to the receding water level below. This means you will always get an OFF signal and you can always rely on your pumps stopping.
Even if the LIT fails (or power fails to the LIT) you will get an OFF signal because the level relays will all spring open.
With the right combination of grease buildup it’s possible to get the situation where contacts 1 and 2 are shorted together (by water held inside the grease). It doesn’t cause any problem without a low level alarm – but if you have used 1 for low level and 2 for OFF, you might get low level alarms – even though the pump would still stop at the low level alarm point. This is why we recommend not having a low level alarm with the FOGRod.
Even though it seems on the surface like a good idea, we suggest not having a low level alarm, here’s why..
One of the great features of the FOGRod is the reliability of the OFF signal. Once the water drops off the bottom of the rod there is no way for current to flow through fresh air to ground. The low voltage applied to each contact on the FOGRod has to jump through fresh air to the receding water level below. This means you will always get an OFF signal and you can always rely on your pumps stopping.
Even if the LIT fails (or power fails to the LIT) you will get an OFF signal because the level relays will all spring open.
With the right combination of grease buildup it’s possible to get the situation where contacts 1 and 2 are shorted together (by water held inside the grease). It doesn’t cause any problem without a low level alarm – but if you have used 1 for low level and 2 for OFF, you might get low level alarms – even though the pump would still stop at the low level alarm point. This is why we recommend not having a low level alarm with the FOGRod.
The FOGRod relies on conductivity for measurement. So it doesn’t measure petrochemical levels – like oil and diesel. And if there is a mix of oil and water it is unlikely the FOGRod will work properly – basically the oil in the water will coat the unit and insulate the contacts from the water.
Sludge is another bad application – but it does depend on the amount of sludge. If you have “enough” wet sludge, it will coat the rod and form a conductive layer, preventing the FOGRod from making good measurements.
The reason the FOGRod works great in wastewater applications – even though it is not obvious or easy to see – is the grease usually gets broken up and so does not form a perfect insulator over the FOGRod contacts. We designed the FOGRod (actually the software in the LIT that connects to the FOGRod) to detect if one or more of the contacts has got insulated and still keep the pumps starting and stopping. So if you have an application where you think the liquid mix might cause this problem please call us on 406 545 3023 to discuss it.
If we don’t think something will work – we will tell you.
The FOGRod comes in three lengths – 7.5 ft, 5 ft and 3 ft. The separation between each contact is 9″ for the 7.5′, 6″ for the 5′ and 3″ for the 3′ Fogrod. They are the same price.
For longer Fogrods, see the next question – we use two Fogrods..
The FOGRod comes in three lengths – 7.5, 5 and 3 ft. For longer than 7.5 ft we use two Fogrods.
The longer rod (7.5 ft) covers the operating range of most lift stations. The usual reason for requesting something longer than 7.5 ft is to provide a “high-high alarm”.
We recommend using a high level float for this high-high alarm because floats are very reliable when they aren’t hanging in wastewater. So one float, just for occasional use, is a good choice.
For those occasions where the operating range is actually greater than 7.5 ft, we offer two FOGRods. Hang one above the other and connect every 2nd wire into the LIT (the FOGRod control panel unit).
The reason we don’t manufacture individual 10 ft or 15 ft Fogrods is because they are very expensive to freight and much more easily broken.
Here is an example installation with 2 Fogrods:
We try and ensure we always have stock available.
A lot of companies try to run on very little stock and they make you wait 8 weeks after you place a purchase order before they ship your product.
We have a different philosophy and our aim is to ship your PO next day, and most of the time we have stock of all of our part numbers.
Of course, day to day, the situation changes and we can’t always achieve this. If you need to know our delivery time, please call us on 406 545 3023, or email us: sales@wastewater-level.com. We will always do everything we can to get your order to you for when you need it.
Our US inventory is warehoused in Lancaster, Pennsylvania and we typically ship by Fedex ground. This means that shipments usually arrive within 2-3 days in most of the eastern half of the country, and 4 days in the western half of the country.
Within the US, the price of our system includes delivery by ground shipment to the continental US. If you need something air freighted overnight, we will do it no problem – but of course we need to bill you for the shipping cost. Just ask and we will let you know the options.
10 – gray (top contact)
9 – purple
8 – yellow
7 – brown
6 – blue
5 – orange
4 – green
3 – white
2 – red
1 – black (bottom contact)
and the 11th wire – pink – is a “failsafe” wire to allow the LIT (Level Indicator Transmitter) to check cable integrity.
Both units work on exactly the same principle. But there are some significant differences:
a) Toughness – the FOGRod has been designed to withstand a lot more impact than the Multitrode® probe. You can see a video of the FOGRod being thrown up into the air and bouncing off concrete without cracking. This is due to a number of factors including better design and better materials.
b) Shielded cable – modern instruments have shielded cable to avoid noise, e.g. from motors, affecting their measurements. The FOGRod has a shielded cable, whereas the Multitrode probe does not.
c) Cable integrity – the FOGRod cable is inherently tougher due to its braided shield, but it also has a failsafe core, which allows the LIT to test for cable breaks and cable short-circuits.
d) Price – the FOGRod is about half the price of the Multitrode “probe”.
The FOGRod works in any conductive liquid.
The toughness and simplicity of the product were designed to suit the nasty environment of wastewater – and lots of different organizations apart from municipal organizations also have to deal with wastewater. So the FOGRod is installed in meat processing plants, major casinos, hotels & motels, hospitals, schools, libraries and universities. And probably also in lots of places we haven’t found out about.
There are many process applications in water and wastewater treatment that rely on measuring liquid level and the FOGRod is a great choice in most of those.
The FOGRod is also installed in a craft brewery – in the process. This process can go from a pH of 2 to 11. Our first question was whether there was any PVC in that tank and whether it had been there for a while. When we were told that this was the case we recommended the FOGRod and sure enough it has worked great.
The essential materials in our level sensing device are PVC, PVC cable jacket and AL6XN which is a super-high grade stainless (read about AL6XN here). This means that if you have an application with nasty chemicals we can look up the corrosion rates in standard tables – but if you already have PVC in the application and it has survived, you can be sure the FOGRod will also survive.
The warranty is in our Terms of Sale document on page 4.
