*IMPORTANT*
It is very important (if you do not know already) to find the cause of failure. The three most common causes of
drive destruction are:
1) Overvoltage
2) Overcurrent
3) Overheating
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OVERVOLTAGE |
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35 VDC is the absoulte maximum the drive board can handle without being permamnently damaged. It is the system integrators responsibility to ensure that the drive system is protected from overvoltages. The maximum suggested running power supply voltage is 30VDC. |
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An overvoltage condition generally occurs when an energized motor connection breaks. This can be due to connector disconnect or broken wiring. Inspect the connections and wiring for this sort of symptom. Use good connectors that will not come loose during normal operation. Do not allow cabling to repeatedly bend back and forth such that is will cause the wires to break. |
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A more uncommon overvoltage condition can be cause by static discharges. Static charges can be built up by vacuum systems that are not properly grounded. An unshielded, uninsulated flexible wire should run the length of the inside of the vacuum tube and be connected to earth ground. High voltages produced by Plasma cutting arc can also cause problems if the system is not properly grounded and sheilded. |
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Plasma cuttings system must make sure that generated high voltages are not allowed to get to either the system signal wiring (STEP and DIR lines), or to the drive board through the motor cabling. |
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OVERCURRENT |
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An overcurrent can happen when motor wires are improperly wired up (cross connecting the phases) Double checking all the connetions for proper wiring during setup can eliminate this cause. Shorts can also cause this problem. Common causes of this are poor connenctions that leave a small wire strand able to short across to either another phase wire or a connector shell. Finally small chips or metalic dust can land on the board causing a short (this is a frequent cause of failure). Keeping the board in a clean environment can help eliminate this cause. |
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OVERHEAT |
| Overheating can occur if a fan stops working or becomes clogged. If the drive is placed inside an enclosure proper airflow is very important. When using an enclosure consider using two fans: One to pull in cool air into the case, and another to blow directly over the heatsink. Make sure there are adequate venilation holes to allow warm air to exhaust. One fan circulating warm air inside an enclosure will be of little or no help. Overheating can occur if the drives have their Vref set past the maximum or if inadeqaute cooling is provided. |