Lowrance EP 60R calibration

msgchef · Posted: Sun Jul 26, 2015 12:34 pm Post subject: Lowrance EP 60R calibration

Hi
I have discovered that there is a substantial variance between my analog fuel gauge and the lowrance EP 60R in line fuel monitor. The data is displayed on a Raymarine a98 MFD. The Lowrance manual describes how to calibrate to actual usage however only on a Lowrance device with its corresponding menu. In looking at my Raymarine setup menu there is no such calibration menu.
Anyone have thoughts on how to get this device to be accurate to my analog fuel gauge.
thanks
Paul

thataway · Posted: Sun Jul 26, 2015 1:18 pm Post subject:

The lowrance EP 60R is a fuel flow sensor. You need a minimum of a LMF-200 (2" display) to calibrate the fuel flow.

You are talking about an analogue fuel gauge, vs fuel flow. How accurate is the fuel flow? This has to be accurate first, then you can calibrate the size of tank, and with the fuel flow it will give you a close correlation with the amount of fuel in the tanks. I have had the Lowrance fuel flow sensors on several boats, and they work fine.

This is one of the issues of combining NMEA 2000 devices from one manufacture, with a display from another brand. Use the new LMF-200 as your fuel flow and tank display…Probably not what you wanted to hear.

msgchef · Posted: Sun Jul 26, 2015 2:12 pm Post subject:

Thx Dr. Bob. Not what I was hoping but not too unexpected after researching a bit
Paul

journey on · Posted: Sun Jul 26, 2015 3:04 pm Post subject:

I'm curious. On Journey On the fuel gauge reads a float level in the gas tank. This device is a float at the end on a swinging arm, which moves a resistor. The gauge reads the current through the resister. At least in Journey On, that whole system is non-linear. I can get another 10 gal in the tank after the gauge reads full and I probably only have 40 gal in the tank when the gauge is half full.

Is this the analog fuel gauge to which you're referring? It's not something I'd use as a standard.

I installed a Navman 3100 fuel flow system, which uses a fuel driven turbine and counts the revolutions. It's been fairly accurate, even at the low flow rates Journey On sees. So the EP-60R is a similar turbine with a NMEA 2000 interface, with which the Raymarine a98 MFD will interface and, I take it, reads. The NMEA message that the sensor transmits is NMEA 2000 PGN 12489, Engine Parameters, Dynamic, where field 6 is the fuel rate. There is no field for the total fuel used, that parameter is calculated in the display, which is why Lowrance says it's proprietary.

Nevertheless, if the fuel flow comes in as a standard NMEA 2000 sentence and the Raymarine MFD can display it, the MFD should be able to give a total value, which it gets by integrating the flow rate. This could be/is? the output total you presently see. So try comparing that total with the gas you use and see what you get. The gas you use estimate shouldn't come from the gauge, but what it takes to refill your tank. If that doesn't agree, talk to Raymarine ( if possible,) and see how you can recalibrate the fuel total. If you can't do it in the MFD, use a factor and mentally multiply the reading shown on the MFD.

Boris

msgchef · Posted: Sun Jul 26, 2015 5:22 pm Post subject:

Your description is accurate. I am reading the results of the float sensor. My recent refill was 55 gal actual, which pretty close matches the gauge. however the MFD reading from the lowrance indicated that I would only need 33 gal. a significant difference. This test was started with actual full tanks to reset the MFD to 100%. At least I know my gauge is working well and certainly sufficient to operate with though I do like my technology. I do have a question on the Raymarine Tech forum to see what that might yield.
Paul

thataway · Posted: Sun Jul 26, 2015 8:14 pm Post subject:

You are under reading the flow, this has to be adjusted. Once adjusted, you will be fine.

journey on · Posted: Sun Jul 26, 2015 8:41 pm Post subject:

OK, what Bob said is true.

Used=55 (by refill?) Indicated= 33 (by flowmeter?)

So try a factor of 55/33= 1 2/3. That certainly seems high, but try it and see if it works. If it does, now all you have to do is see if you can change the Raymarine input to output factor.

BTW, how does the flowrate look. As an example, for Journey On, loaded, at 15 knts in smooth water, a reading of 2.25 nmi/gal is normal. At 7 knts (just above hull speed,) its 4 nmi/gal. That equated to 6.7 gph @ 15 knts and 1.8 @ 7 knts. I also assume that's a very low flow rate for the flow sensor, so I only use that as a reference set of units..

The difference may be in the gal per turbine blade revolution difference between the Raymarine and the Lowrance unit. I assume that the NMEA output is in gal and either the NMEA net or the MFD supplies the time.

Anyway, if you can get a flowrate from the MFD, there's got to be a way to calibrate the device. Read the manual? Download a Raymarine flowmeter manual? Call Raymarine?

As an idle comment the NMEA 2000 bus is built on CAN technology and CAN is used by the auto industry. I'd like to get a CAN to USB adapter and see what the data looks like. If I get into nmea 2000.

Boris

thataway · Posted: Mon Jul 27, 2015 12:57 am Post subject:

I spent a little time on RayMarine, and other forums about this issue:
This seems to give the answer from RayMairne support:

journey on · Posted: Mon Jul 27, 2015 5:36 pm Post subject:

Well, Bob, it turns out that Raymarine doesn't sell a fuel flow sensor. I looked at the a98 MFD instruction manual (not too deeply, mind you) and it shows that it supports NMEA 2000 PGN 12489 (pg 153) and third party fuel sensors (pg 19) as well as shared preferences, such as flow units (pg 90.) And here's a reference on How to Install fuel Flow with Raymarine devices.

It indicates that one needs a NMEA 2000 network, which I assume that Paul has. Note that this doesn't mean the NMEA 2000 compatible Seatalk network, but a true NMEA etc. And then the article goes on to say that Raymarine supports fuel flow, etc. A discussion with Raymaarine is in order. They should help, since they don't sell flowmeters.

I also looked at the EP-60R calibration procedure and it only consists of resetting the total fuel used. I assume that's a running count in the EP-60R. The rest of the calibration concerns only the display unit. So finding the units the EP-60R puts out would help and I assume that means a call to Lowrance. That makes sense since flow rate needs time and a sensor is complicated by reading time and doing the calculation, then outputting the result. Especially since the MFD easily does those things.

And Judy is looking at me as if I'm going crazy, so it's up to you and Paul now. I explain I'm learning about boating networks, which doesn't do any good.

Boris