Ebtron Analog Output Scaling and Testing

Hi- A customer was asking about analog output scaling for Ebtron transmitters— Here is a good place to start:

  1. Probe based airflow stations come default as 0-5000 feet per minute (FPM) on the analog output 1 from the transmitter . Note that this is a VELOCITY and not a VOLUME.

  2. Fan inlet airflow stations come default as 0-10,000 FPM since they are generally a faster speed into the inlet cone.

  3. For most systems, we recommend that you bring all of the transmitters velocity analog output (either 0-10v or 4-20ma based on the dipswitch) into your control system Analog Input (AI) as the same analog scaling— that is, regardless of duct size all of your Ebtron probe transmitters will have the same 0-5000FPM scaling into your AI. We like bringing all of the transmitters in with the same scaling to avoid field confusion— at least initially.

  4. Take each AI and multiply it by the duct area to get an AV showing the VOLUME in CFM.

    VELOCITY x DUCT AREA = VOLUME FLOW

    Having the volume flow be an AV allows you to do other operations on it later that you cant do with an AI*. We can lookup the area from the packing slip if you don’t have it— call us if you need this value.

    *Useful AV operations: You can write a “0” to the AV on a windy rooftop when the unit is off, so there aren’t any weird airflows on the screen to distract the operators.

Here is a math example-

If you brought the 0-10v signal in as 0-5000FPM on a 4’x4’ duct:

5000FPM x 16Ft^2 = 80,000CFM at max flow. This means that 5V at the transmitter should show 40,000CFM on your EMCS display.

Here is how the manual describes it, we did the “manual conversion”:

GTC-116 manual description

GTC-116 manual description

20190513_142253.jpg

USING THE TESTOUT BUILT INTO THE TRANSMITTER:

Ebtron gave us a great tool to help commission this- by going into the setup/tools menu you can force the output to a certain %, and verify that we did all of the steps correctly. If I command the output to 50% I can measure 5v on the output and should see the EMCS display change to 40,000CFM in the above example.

As always, please call us if you have any questions.

Ebtron Probe Adjustments

InControl will be happy to measure and mark the mounting locations for all of our airflow stations-- we do it for free and strongly encourage it.  That way you know that you have the correct size and the best mounting location to make sure we get the full accuracy of the device.

There is some mounting flexibility in the brackets, depending on the installation type:

For internal brackets, aproximately +/- .75" by adjusting the set screw on the mounting feet.  DON'T OVERTIGHTEN the screws on the feet, especially on the cable end.

For insertion mount, the probes are cut full size but there is a 1.5" stud on the non-cable end that allows for some adjustment.  About 1", especially to make the probe fit a LARGER duct than measured.

For standoff mounts, the brackets need to go straight back to the damper frame, there isn't much flexibility on these.  It would be best to get these right on or slightly larger than the damper opening.

Insertion Mount Installation

Internal Mount Installation

Standoff Mount Installation

 

Ebtron internal mount feet

Ebtron internal mount feet

Ebtron insertion mount stud-end

Ebtron insertion mount stud-end