The same complaint that the oil purifier is not working properly takes very different lengths of time to locate, depending on whether it arrives with six pieces of information or only with a statement that there is a problem with the machine. Ten minutes spent organising the information before calling for service saves the time spent on repeated questions afterwards. The six items are the equipment number, the nameplate parameters, the installation date, the oils that have been processed, the most recent abnormal symptom, and the checks that have already been carried out.
Equipment number: one communication, one machine
The equipment number is the only field that can tie a verbal description to a specific machine. Machines of the same model may differ in configuration in actual service, and their running hours, the oils they have processed and their maintenance condition differ as well. Once the number is established, the factory test records, the documentation pack, the spare part specifications and the previous service records can all be pulled up together, and the information changes from guesswork into verification.
The number is normally on the nameplate on the frame or the control cabinet, a small metal plate, and the number on it agrees with the number on the certificate of conformity and on the test records. Taking a photograph of it once and keeping it is a measure that saves all further trouble: every subsequent call for service can simply include the image, so there is no need to go out to the site each time to find the plate, and no need to quote a string of numbers from memory. Photographing the number together with the nameplate also captures the model and the parameters below it.
Nameplate parameters: confirming whether the site conditions match the machine
The three most important items on the nameplate are the model, the flow rate and the power supply conditions. The ZYD-100 has a flow rate of 6000 L/h, a total power of 72 + 5 kW, a three-phase 380V / 50Hz supply and dimensions of 1200×1400×1800 mm. Going through these parameters against the site situation often rules out a batch of hypotheses straight away: if the voltage at the site is chronically low, or if the quantity of oil the customer actually has to process is far beyond the rated flow of the machine, then some of the behaviour is a matter of operating conditions rather than a fault.
The nameplate is also the basis for checking the spare parts. The filter element models and their accuracy specifications are closely tied to the configuration, for instance the 150-500-5 fine filter element, the 150-250-50 and 110-250-50 coarse filter elements, the 110-400-20 secondary filter element and the 110-600-5 fine filter element. Bringing the nameplate photograph when calling for service makes it much less likely that the wrong spare part model is sent. If the accuracy and the specification are chosen wrongly, the element cannot reach the original indicators even after it is fitted, and a whole outage window is wasted, and this kind of mistake is very hard to detect in the store by checking against memory.
Installation date and the oils processed: judging the condition of use
The installation date is used to work out how long the consumable parts have been in service. How long the seals have been in use, when the pump oil was last changed, how many batches of filter elements have been replaced, these calculations are directly relevant to deciding whether the situation is normal wear or abnormal damage. If the installation date cannot be remembered, it is normally in the documentation pack and the installation record supplied at delivery; looking it up and checking it once is enough.
The oils that have been processed have to be provided as well: the type of oil, the water content situation, and whether oils of different grades have been mixed. The oil determines the viscosity and the state of the dissolved gas and water, and the viscosity directly affects the load on the pump and the flow performance, while the water content and the gas content are directly related to the degassing load on the vacuum system. If a machine intended for insulating oil is used continuously on hydraulic oil with a high water content, a fluctuation in the vacuum level is not surprising.
The most recent abnormal symptom and the checks already carried out
The more specific the description of the symptom, the better. Which readings are out of order, when it started, whether it was there from the moment of start-up or appeared only after the machine had been running for a while, and whether it was accompanied by any change in noise or smell, these few items save a large amount of question-and-answer work. At the same time, state the checks that have already been carried out so that the work is not repeated: for example that the pump oil has been changed, that the seals have been inspected, that the inlet strainer has been cleaned, all of which should be written down, including what the result was.
| Information to prepare | Where to get it | What it helps to rule out |
|---|---|---|
| Equipment number | The nameplate on the machine or the control cabinet; a photograph is recommended | Identifying the specific configuration and the factory records |
| Nameplate parameters | Photograph of the nameplate | Confirming whether the duty and the power supply match |
| Installation date | The documentation pack or the installation record | Working out how long the consumable parts have been in service |
| Oils processed | The operating records | Judging whether the application is outside the specified range |
| The abnormal symptom | Readings and observation on site | Narrowing down the direction of the fault |
| The checks already carried out | The operator's records | Avoiding repeating a path that has already been verified |
How much faster the remote diagnosis can be when the information is complete
Take a common case. A customer reports that the vacuum level will not come up, with a measured value of around -0.06 MPa. With a one-line description the only advice that can be given is to check the seals, top up the pump oil, check the filter element, and then wait for a reply. With the six items the direction is far clearer: the installation date indicates whether the seals are due for replacement, the oils processed show whether the water content of the incoming oil is abnormal, the point at which the abnormality appeared distinguishes a low value from the moment of start-up from a fall after a period of running, and the checks already carried out confirm whether the pump oil has just been changed.
- Vacuum level low from the moment of start-up: points first to the system sealing, the pumping speed of the pump set or the pipe connections.
- Fall after a period of running: points first to gas in the incoming oil, insufficient heating temperature or a change in the differential pressure across the filter element.
- Accompanied by abnormal noise from the pump set: check the condition of the pump oil and the alignment of the coupling first, then look at the valve positions.
- Accompanied by a protection trip: record the moment of the trip and the readings at that time, so that the trigger conditions can be located.
Remote diagnosis always has its limits, and the final confirmation usually still has to be made on site. With the information complete, however, the technician can set off with a clear suspect and a list of spare parts instead of a set of general tools and a hope of finding the fault. Making these six items a fixed routine before every call for service is the least costly step towards shortening the downtime.
Ten minutes spent sorting out the six items before the call for service saves the half day of question and answer that follows; when the information is incomplete, the investigation starts at the most likely place and takes the long way round.