Shenzhen Hpmont Technology Co., Ltd.
Chapter 4 Electrical Installation
HD3N-L Series User Manual V1.0
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4.6.4
Ground Connection
The grounding terminals PE must be connected to ground properly for the controller has leakage
current to the ground. The grounding point should be as close to the controller as possible, and the
grounding area should be as large as possible to make sure that the grounding resistance should be
less than 10Ω.
Do not share the grounding wire with other devices (A). HD3N-L can share grounding pole with other
devices (C). It achieves the best effect if HD3N-L and other devices use dedicated grounding poles (B),
as shown in Figure 4-7.
Figure 4-7 Grounding method
When using more than one controller, be careful not to loop the ground wire as shown in Figure 4-8.
Figure 4-8 Prohibited grounding method
4.6.5
EMI Filter
The EMI filter should be used in equipment that may generate strong EMI or equipment that is
sensitive to external EMI. The EMI filter is a dual-way low pass filter through which lower frequency
current can flow while higher frequency current can hardly flow.
Function of EMI filter
1.
The EMI filter ensures the equipment not only satisfy the conducting emission and conducting sensitivity in
EMC standard but also suppress the radiation of the equipment.
2.
It can prevent the EMI generated by equipment from entering the power cable and the EMI generated by
power cable from entering equipment.
Common Mistakes in Using EMI Filter
1.
Too long the power cable is between the EMI filter and the controller.
The filter inside the cabinet should be located near to the input power source. The length of the power cables
should be as short as possible.
2.
Too close the input and output cables of the EMI filter.
The distance between input and output cables of the filter should be as far apart as possible. Otherwise the
high-frequency noise may be coupled between the cables and bypass the filter. Thus, the filter will become
ineffective.
Controller
Other
Controller
PE
PE
A. Sharing grounding wire
PE
PE
B. Dedicated grounding pole
PE
PE
C. Sharing grounding pole
Other
Controller
Other
Controller
Controller
Controller
Controller
PE
PE
PE
PE
Prohibited grounding method
4
