Don’t learn from the butterfly fluttering aimlessly from flower to flower in a garden.
Think and work in logical order and literally follow the direction of the current whether talking about hydraulic or electrical currents.
1. Start with the beginning: Is there any oil in the tank?
Are there pressure and flow at all on the hydraulic installation? If there are abnormal conditions here the error may be either hydraulic or electrical.
Therefore: Determine whether the error is electrical or hydraulic, but remember:
Without specified pressure and flow it is not easy to find the cause of failure.
2. Next item: Power supply.
Don’t ask if there is current on the accumulator/battery – the answer will always be:
“Yes, of course”.
This would also be the reply if we asked whether there is oil in the tank.
It is safer to check whether the battery voltage is correct.
Also check whether there is water on the battery cells. If a lot of water is missing the terminal voltage of the battery may be o.k. in unloaded condition, but loaded it will drop many volts.
3. Are the fuses intact and emergency stop and/or key contacts, if any connected?
Has a lead perhaps been shaken loose in a terminal board in the mix box?
4. Are the leads from the power supply correctly polarized, plus to plus and minus to minus?
A PVE of the ON/OFF type will e.g. work correctly even if plus and minus has been switched whereas a PVE of the proportional type in that case will be completely dead.
Therefore, try to switch the Hirschmann plugs on an ON/OFF and a proportional PVE, respectively and check the functions again.
These totally fundamental conditions must naturally be all right before we start looking at the individual components and their inlines.
• The kind of failure and influence on the system
• For how long has he noticed that something was going wrong
• Has he been “fiddling” with leads and plugs himself, and
• Has he got hydraulic and electrical diagrams at his disposal?
Such diagrams are often enclosed with the directions for use following the installation. Unfortunately, they are often so schematic that they are not very useful anyway in a trouble shooting situation; still, they do show the order and the connections between the individual components.
Finally, a piece of good advice:
THINK before ACTING
Take NOTES – they might turn out to be useful the next time.
In that way you gather EXPERIENCE