SCUBA Diving

How to replace a solenoid from your Poseidon eCCR

Discussion about solenoid replacement on the MKVI eCCR

I understand that a diving company should make all possible actions to ensure that his products remain safe and in perfect order so the user is not endanger.

Nonetheless, there are users that are more than capable of repair or modify equipment following their needs. Actually this is how some old players started in the business.

So, for those mechanics oriented guys you’ll find that with proper training, studies and curiosity, servicing your on equipment, it’s at your reach.

This project begins when one solenoid of my CCR clogged. So if you have an error in one of the “automatic pre-dive tests”, the unit will display an error code number of the failed test and will shoot down. As wrote on the manual: “If a test fails, the test number flashes, and the “spinning wheel” indicator on the right side of the display is replaced by a flashing error code, indicating what aspect of the test failed”.

The standard response to failure is simple: first, check the state of the battery, that it is not under/over charged and that it does not require a learn cycle, so battery issue may lead to trouble. Next, reboot or reset the battery. After that, you need to consult the troubleshooting table.

One interesting suggestion is “reset system parameters”. In some cases, a test may fail because some of the user selected parameters have become corrupted. Thus, for certain tests, the Configuration PC software can be used to reset system parameters.

Anyway, if you are done with all the suggestions and the problem was no fixed, you need to download a logbook called “red” something like a “black-box”that register all tests on your electronic CCR. You must send the file to Poseidon and they will tell you if you can fix it or not.

For example, in my case the unit got an error code on test 53, which means that the unit couldn’t calibrated the sensors, this test is actually based on a a few factors, such as:

  • Temperature of the sensors
  • Percentage of oxygen in the gases used
  • Response time from a sensor
  • Milli voltage reading

As it is wrote on the manual: “the test will start by injecting pure oxygen directly on the primary oxygen sensor for 20 continuous seconds. After the calibration constants for oxygen are established, the system then injects diluent (air) via the diluent calibration solenoid valve. In doing so, this test calibrates the primary sensor, and confirms that the correct gas mixtures are used in the respective cylinders.
This means, that the milli volt reading from a sensor alone can’t be used to establish if an oxygen sensor is working properly or not. The response time of an oxygen sensor differs based on the temperature of the oxygen sensor. This means that the temperature of an oxygen sensor can have a big effect on the success of a Pre Dive calibration.”

To resolve the problem:

  • Verify that the gas cylinders are connected to the correct pneumatic blocks LP connections
  • (DIL/O2). – Make sure the cylinders contain the correct gas mix
  • If winter diving, warm the sensors up, in your pocket
  • If the unit keeps failing test 53, you might have to replace one or both oxygen sensors.
  • If test failure persist, contact an authorized Poseidon Service Center for repair.

So, one clue of what’s happening is the sub-number test: 68. The complete error code number is 53-68. This secondary displayed number (68) tells me: “primary diluent high”. Meaning that the unit is reading a low pO2 regardless the amount of oxygen that the controller is injecting into the unit.

What is forcing the unit to keep a low pO2?

There are 4 solenoids in the unit, and the primary diluent solenoid is not closing, is leaking, thus no matter how much oxygen the unit inject the pO2 will not rise up.

Solution: send the head back HQ or a qualify technician to be replaced. Which not all countries or regions has.

Send the head back is costly, time consuming and so on. At that time, being already a “regular” technician on the unit, I decided to take the matters on my own hands.

I disassembled the head, once the two main pieces of the head were apart; but both computer and electronics boards connected, I started the pre-dive tests. Exactly on the test 53-68 I could heard and felt the gas streaming from the solenoid without stopping. Eureka… I identified the leaking solenoid. Now, I had to continue taking apart the head and electronics to get access to the solenoid and replaced it.

All the procedure must be executed carefully taking special attention to not damage the electronics and cables.

The part number is: 0000-649

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