How do you maintain EMC with cabinetÆs open?
How do you maintain EMC with cabinetÆs open?
(OP)
I was wondering if anyone has heard of anyone addressing the problem of maintaining EMC when the cabinet that contains EMI/RFI sensitive equipment is open for maintenance or testing. All the Regulations (Regulatory Guide 1.180, EPRI TR-102323, FCC, etc.) talk about the limits that must be maintained in order to maintain EMC, and to get to that limit you must provide shielding (EMI cabinet). But the issue of opening these cabinets to perform maintenance, while the equipment is in use, is not addressed. Has anyone heard anything on this issue?
RE: How do you maintain EMC with cabinetÆs open?
If it's more a question of adjustment, then ideally your design should include suitable adjustment control points, test connectors, etc., brought to a controlled shielded area. This allows adjustment without "opening the box" and the test area is covered with a flap or similar, once the equipment has been adjusted, just to make sure.
RE: How do you maintain EMC with cabinetÆs open?
I guess I should restate my original question a bit clearer. I was wondering if anyone out there knows why it seems that the EMC community seems to ignore real world situations that require the equipment, within a cabinet, to be tested/maintained while still fully functioning. I work at a nuclear power plant and it is not feasible to just deactivate equipment to perform testing/maintenance (say for example a redundant power supply within a cabinet fails). Not only do standards and regulations “seem” to ignore this; they don’t even cover why it is not an issue. The closest thing I have found that touches on this issue is that the FCC has a disclaimer that manufactures put on their products. “…shall caution the user that changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment” i.e. the equipment has exceeded FCC limits (FCC Part 15.21) It seems to me that if you have to shield equipment to meet EMC limits, that the issue of opening the cabinet should also be covered in standards/regulations.
RE: How do you maintain EMC with cabinetÆs open?
RE: How do you maintain EMC with cabinetÆs open?
such matters are addressed in your design objectives as they relate to maintenence.
RE: How do you maintain EMC with cabinetÆs open?