G
georgi
Hi everyone.
I'm trying to figure out an issue with electromagnetic interference caused by equipment at a store above which I live. No formal qualifications here though I've studied some of this in the past. The store's cooling shelves are switched on and off by a timer. When the equipment is on (6am-11pm every day) I can pick up really strong RF emissions which make for a fine buzz all over the long wave and medium wave radio spectra, jamming every weak station. Apparently the "noise" is strong enough to disrupt broadband (adsl) services on the phone line (150khz-1mhz), I guess the unshielded phone wires make for a fine antenna. Strong harmonics at 100, 200, 300, 400, etc. Hz of any signal my radio picks up.
I suspected the store's main lights (ballast or dimmer issue), but it looks like it's the cooling units (been investigating what I can all of last week). In addition to cooling the shelves have fluorescent lights behind their transparent sliding doors. I would state the model if I knew it. Anyway, store people aren't keen on fault-finding at all and are not cooperating.
I'm curious as to the standards these things must adhere to, regarding EM emissions? I tried browsing for a suitable BS (standard) but the list is a maze to a layman like me. Surely RF emissions must be kept under control even on commercial high-powered units?
I'd really appreciate if someone could point out the regulation involved, and maybe advise on standard solutions to kill EM emissions at source? Grateful for any info!
I'm trying to figure out an issue with electromagnetic interference caused by equipment at a store above which I live. No formal qualifications here though I've studied some of this in the past. The store's cooling shelves are switched on and off by a timer. When the equipment is on (6am-11pm every day) I can pick up really strong RF emissions which make for a fine buzz all over the long wave and medium wave radio spectra, jamming every weak station. Apparently the "noise" is strong enough to disrupt broadband (adsl) services on the phone line (150khz-1mhz), I guess the unshielded phone wires make for a fine antenna. Strong harmonics at 100, 200, 300, 400, etc. Hz of any signal my radio picks up.
I suspected the store's main lights (ballast or dimmer issue), but it looks like it's the cooling units (been investigating what I can all of last week). In addition to cooling the shelves have fluorescent lights behind their transparent sliding doors. I would state the model if I knew it. Anyway, store people aren't keen on fault-finding at all and are not cooperating.
I'm curious as to the standards these things must adhere to, regarding EM emissions? I tried browsing for a suitable BS (standard) but the list is a maze to a layman like me. Surely RF emissions must be kept under control even on commercial high-powered units?
I'd really appreciate if someone could point out the regulation involved, and maybe advise on standard solutions to kill EM emissions at source? Grateful for any info!