Which button is pressed first and which pump starts first is often covered by a single line in the site operating instructions. The order itself, however, has a purpose: power on, heating, pulling the vacuum, charging the oil. Each step solves a specific problem, and if the order is wrong the effect of every later step is reduced.
First step: power on and self-test
After the supply is closed, the machine carries out a self-test, and at this stage nothing moves yet. The phase failure and phase sequence protection confirm that the supply conditions are right, the door interlock confirms that the door is closed, the infrared level detection confirms that there is oil in the chamber, the foam detection confirms that there is no abnormal foam, and the over-pressure audible and visual alarm circuit confirms that it works. The power supply of the ZYD-100 is three-phase 380V / 50Hz, and a phase failure or a wrong phase sequence should be stopped at this point rather than becoming visible after the pumps have started.
The self-test is passed before the work continues because every later step rests on those conditions. If the machine is carried on with a phase missing or a door open, none of the data measured afterwards can serve as a basis for judgement.
Second step: heat up to the control range
The oil temperature decides the atomisation and the flow that follow. The control range is 45–80 °C, and the upper limit is reduced to 70 °C when the water content is high. The heating uses far-infrared carbon fibre and needs time to bring the oil up. The point of heating in advance is that the viscosity has already fallen when the oil enters the degassing chamber, so the atomisation is finer and the resistance through the filtration section is lower.
If this step is skipped and cold oil is charged, the oil has to be heated inside the chamber afterwards, and that heating is both slow and uneven, so the degassing efficiency is clearly lower in the first part of the run. The machine looks as if it is working, the gas content stays close to the ≤0.01% line of GB/T 423, and it becomes hard to tell whether this is a process problem or simply that the temperature has not been reached yet.
Third step: pull the vacuum and charge the oil
The X-100 vacuum pump starts, the JRP-500 roots blower is brought in as booster in the correct order, and the oil is charged only after the vacuum level has been established in the chamber. The reason for pulling the vacuum first is that once the oil is in the chamber it is filled with an oil vapour mixture, and reaching the ultimate vacuum from that state takes noticeably longer.
After charging, the ZH screw oil pump delivers the oil to the degassing chamber, where it is atomised. The gas and the water dissolved in the oil are released, separated in the condensing section and drawn off by the vacuum section. This is the stage at which the machine starts to deliver real throughput, and once the circulation has settled the machine can run continuously.
| Step that is skipped | What appears immediately | What has to be paid for later |
|---|---|---|
| Charging without heating | Low degassing efficiency at the start, the gas content stays high | The oil heats up slowly inside the chamber and the whole period runs at reduced efficiency |
| Charging without pulling the vacuum | More gas in the chamber, the vacuum level builds slowly | The time needed to pull the vacuum again is longer |
| Carrying on after a failed self-test | Unreliable data, or running with a fault present | The machine is stopped and restarted, and the fault is hidden |
| Charging before the temperature has settled | The temperature keeps climbing during the run | Once the set point is reached, a further settling period is still needed |
Stopping and starting again
- The stop sequence is the reverse of the start sequence: stop the oil feed first and let the oil in the chamber finish circulating, then stop the pumps one by one, and switch the power off last so that the heating section cools down on its residual heat.
- When starting again after a short stop, check whether the oil level in the chamber and the temperature are still within the set values, which saves a heating period.
- After a long period out of use, the checks before starting are not the same as in normal running; go through the restart routine first.
- Record the temperature setting, the actual oil temperature and the vacuum reading on every start. Put several of these records side by side and deviations show up most easily in them.
The exact operating steps follow the documentation supplied with the machine, because the configuration differs from model to model. The reasoning behind the order is general, though: confirm the conditions first, establish the state second, apply the load last. If any one of them is missing, the judgement made afterwards loses its basis.
The startup order is not a formality; it is what makes every reading credible from the first minute.
