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12 electromagnetic/induction noise, 13 environmental condition – Delta BLD-E1 brushless DC motor drive BLD-E1 Series User Manual

Page 156

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| BLD-E1 Series

Revision May 2009, 00DE, V0.50

5-9

5.12 Electromagnetic/Induction Noise

Many sources of noise surround brushless DC motor drives and penetrate it by radiation or

conduction. It may cause malfunction of the control circuits and even damage the brushless DC

motor drive. Of course, there are solutions to increase the noise tolerance of a brushless DC motor

drive. But this has its limits. Therefore, solving it from the outside as follows will be the best.

1.

Add surge suppressor on the relays and contacts to suppress switching surges.

2.

Shorten the wiring length of the control circuit or serial communication and keep them

separated from the power circuit wiring.

3.

Comply with the wiring regulations by using shielded wires and isolation amplifiers for

long length.

4.

The grounding terminal should comply with the local regulations and be grounded

independently, i.e. not to have common ground with electric welding machines and other

power equipment.

5.

Connect a noise filter at the mains input terminal of the brushless DC motor drive to filter

noise from the power circuit.

In short, solutions for electromagnetic noise exist of “no product”(disconnect disturbing equipment),

“no spread”(limit emission for disturbing equipment) and “no receive”(enhance immunity).

5.13 Environmental Condition

Since the brushless DC motor drive is an electronic device, you should comply with the

environmental conditions. Here are some remedial measures if necessary.

1.

To prevent vibration, the use of anti-vibration dampers is the last choice. Vibrations must

be within the specification. Vibration causes mechanical stress and it should not occur

frequently, continuously or repeatedly to prevent damage to the brushless DC motor drive.

2.

Store the brushless DC motor drive in a clean and dry location, free from corrosive

fumes/dust to prevent corrosion and poor contacts. Poor insulation in a humid location

can cause short-circuits. If necessary, install the brushless DC motor drive in a dust-proof

and painted enclosure and in particular situations, use a completely sealed enclosure.

3.

The ambient temperature should be within the specification. Too high or too low

temperature will affect the lifetime and reliability. For semiconductor components, damage

will occur once any specification is out of range. Therefore, it is necessary to periodically

check air quality and the cooling fan and provide extra cooling of necessary. In addition,

the microcomputer may not work in extremely low temperatures, making cabinet heating

necessary.